Optimize.py 158 KB
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from __future__ import absolute_import

from . import TypeSlots
from .ExprNodes import not_a_constant
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import cython
cython.declare(UtilityCode=object, EncodedString=object, BytesLiteral=object,
               Nodes=object, ExprNodes=object, PyrexTypes=object, Builtin=object,
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               UtilNodes=object)

from . import Nodes
from . import ExprNodes
from . import PyrexTypes
from . import Visitor
from . import Builtin
from . import UtilNodes
from . import Options

from .Code import UtilityCode
from .StringEncoding import EncodedString, BytesLiteral
from .Errors import error
from .ParseTreeTransforms import SkipDeclarations
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import copy
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import codecs

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try:
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    from __builtin__ import reduce
except ImportError:
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    from functools import reduce

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try:
    from __builtin__ import basestring
except ImportError:
    basestring = str # Python 3

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def load_c_utility(name):
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    return UtilityCode.load_cached(name, "Optimize.c")
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def unwrap_coerced_node(node, coercion_nodes=(ExprNodes.CoerceToPyTypeNode, ExprNodes.CoerceFromPyTypeNode)):
    if isinstance(node, coercion_nodes):
        return node.arg
    return node

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def unwrap_node(node):
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    while isinstance(node, UtilNodes.ResultRefNode):
        node = node.expression
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    return node
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def is_common_value(a, b):
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    a = unwrap_node(a)
    b = unwrap_node(b)
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    if isinstance(a, ExprNodes.NameNode) and isinstance(b, ExprNodes.NameNode):
        return a.name == b.name
    if isinstance(a, ExprNodes.AttributeNode) and isinstance(b, ExprNodes.AttributeNode):
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        return not a.is_py_attr and is_common_value(a.obj, b.obj) and a.attribute == b.attribute
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    return False

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def filter_none_node(node):
    if node is not None and node.constant_result is None:
        return None
    return node

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class IterationTransform(Visitor.EnvTransform):
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    """Transform some common for-in loop patterns into efficient C loops:

    - for-in-dict loop becomes a while loop calling PyDict_Next()
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    - for-in-enumerate is replaced by an external counter variable
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    - for-in-range loop becomes a plain C for loop
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    """
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    def visit_PrimaryCmpNode(self, node):
        if node.is_ptr_contains():
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            # for t in operand2:
            #     if operand1 == t:
            #         res = True
            #         break
            # else:
            #     res = False
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            pos = node.pos
            result_ref = UtilNodes.ResultRefNode(node)
            if isinstance(node.operand2, ExprNodes.IndexNode):
                base_type = node.operand2.base.type.base_type
            else:
                base_type = node.operand2.type.base_type
            target_handle = UtilNodes.TempHandle(base_type)
            target = target_handle.ref(pos)
            cmp_node = ExprNodes.PrimaryCmpNode(
                pos, operator=u'==', operand1=node.operand1, operand2=target)
            if_body = Nodes.StatListNode(
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                pos,
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                stats = [Nodes.SingleAssignmentNode(pos, lhs=result_ref, rhs=ExprNodes.BoolNode(pos, value=1)),
                         Nodes.BreakStatNode(pos)])
            if_node = Nodes.IfStatNode(
                pos,
                if_clauses=[Nodes.IfClauseNode(pos, condition=cmp_node, body=if_body)],
                else_clause=None)
            for_loop = UtilNodes.TempsBlockNode(
                pos,
                temps = [target_handle],
                body = Nodes.ForInStatNode(
                    pos,
                    target=target,
                    iterator=ExprNodes.IteratorNode(node.operand2.pos, sequence=node.operand2),
                    body=if_node,
                    else_clause=Nodes.SingleAssignmentNode(pos, lhs=result_ref, rhs=ExprNodes.BoolNode(pos, value=0))))
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            for_loop = for_loop.analyse_expressions(self.current_env())
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            for_loop = self.visit(for_loop)
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            new_node = UtilNodes.TempResultFromStatNode(result_ref, for_loop)
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            if node.operator == 'not_in':
                new_node = ExprNodes.NotNode(pos, operand=new_node)
            return new_node

        else:
            self.visitchildren(node)
            return node
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    def visit_ForInStatNode(self, node):
        self.visitchildren(node)
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        return self._optimise_for_loop(node, node.iterator.sequence)
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    def _optimise_for_loop(self, node, iterator, reversed=False):
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        if iterator.type is Builtin.dict_type:
            # like iterating over dict.keys()
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            if reversed:
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                # CPython raises an error here: not a sequence
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                return node
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            return self._transform_dict_iteration(
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                node, dict_obj=iterator, method=None, keys=True, values=False)
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        # C array (slice) iteration?
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        if iterator.type.is_ptr or iterator.type.is_array:
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            return self._transform_carray_iteration(node, iterator, reversed=reversed)
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        if iterator.type is Builtin.bytes_type:
            return self._transform_bytes_iteration(node, iterator, reversed=reversed)
        if iterator.type is Builtin.unicode_type:
            return self._transform_unicode_iteration(node, iterator, reversed=reversed)
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        # the rest is based on function calls
        if not isinstance(iterator, ExprNodes.SimpleCallNode):
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            return node

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        if iterator.args is None:
            arg_count = iterator.arg_tuple and len(iterator.arg_tuple.args) or 0
        else:
            arg_count = len(iterator.args)
            if arg_count and iterator.self is not None:
                arg_count -= 1

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        function = iterator.function
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        # dict iteration?
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        if function.is_attribute and not reversed and not arg_count:
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            base_obj = iterator.self or function.obj
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            method = function.attribute
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            # in Py3, items() is equivalent to Py2's iteritems()
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            is_safe_iter = self.global_scope().context.language_level >= 3
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            if not is_safe_iter and method in ('keys', 'values', 'items'):
                # try to reduce this to the corresponding .iter*() methods
                if isinstance(base_obj, ExprNodes.SimpleCallNode):
                    inner_function = base_obj.function
                    if (inner_function.is_name and inner_function.name == 'dict'
                            and inner_function.entry
                            and inner_function.entry.is_builtin):
                        # e.g. dict(something).items() => safe to use .iter*()
                        is_safe_iter = True
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            keys = values = False
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            if method == 'iterkeys' or (is_safe_iter and method == 'keys'):
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                keys = True
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            elif method == 'itervalues' or (is_safe_iter and method == 'values'):
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                values = True
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            elif method == 'iteritems' or (is_safe_iter and method == 'items'):
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                keys = values = True
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            if keys or values:
                return self._transform_dict_iteration(
                    node, base_obj, method, keys, values)
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        # enumerate/reversed ?
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        if iterator.self is None and function.is_name and \
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               function.entry and function.entry.is_builtin:
            if function.name == 'enumerate':
                if reversed:
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                    # CPython raises an error here: not a sequence
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                    return node
                return self._transform_enumerate_iteration(node, iterator)
            elif function.name == 'reversed':
                if reversed:
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                    # CPython raises an error here: not a sequence
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                    return node
                return self._transform_reversed_iteration(node, iterator)
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        # range() iteration?
        if Options.convert_range and node.target.type.is_int:
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            if iterator.self is None and function.is_name and \
                   function.entry and function.entry.is_builtin and \
                   function.name in ('range', 'xrange'):
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                return self._transform_range_iteration(node, iterator, reversed=reversed)
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        return node
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    def _transform_reversed_iteration(self, node, reversed_function):
        args = reversed_function.arg_tuple.args
        if len(args) == 0:
            error(reversed_function.pos,
                  "reversed() requires an iterable argument")
            return node
        elif len(args) > 1:
            error(reversed_function.pos,
                  "reversed() takes exactly 1 argument")
            return node
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        arg = args[0]

        # reversed(list/tuple) ?
        if arg.type in (Builtin.tuple_type, Builtin.list_type):
            node.iterator.sequence = arg.as_none_safe_node("'NoneType' object is not iterable")
            node.iterator.reversed = True
            return node

        return self._optimise_for_loop(node, arg, reversed=True)
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    PyBytes_AS_STRING_func_type = PyrexTypes.CFuncType(
        PyrexTypes.c_char_ptr_type, [
            PyrexTypes.CFuncTypeArg("s", Builtin.bytes_type, None)
            ])

    PyBytes_GET_SIZE_func_type = PyrexTypes.CFuncType(
        PyrexTypes.c_py_ssize_t_type, [
            PyrexTypes.CFuncTypeArg("s", Builtin.bytes_type, None)
            ])

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    def _transform_bytes_iteration(self, node, slice_node, reversed=False):
        target_type = node.target.type
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        if not target_type.is_int and target_type is not Builtin.bytes_type:
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            # bytes iteration returns bytes objects in Py2, but
            # integers in Py3
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            return node

        unpack_temp_node = UtilNodes.LetRefNode(
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            slice_node.as_none_safe_node("'NoneType' is not iterable"))
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        slice_base_node = ExprNodes.PythonCapiCallNode(
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            slice_node.pos, "PyBytes_AS_STRING",
            self.PyBytes_AS_STRING_func_type,
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            args = [unpack_temp_node],
            is_temp = 0,
            )
        len_node = ExprNodes.PythonCapiCallNode(
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            slice_node.pos, "PyBytes_GET_SIZE",
            self.PyBytes_GET_SIZE_func_type,
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            args = [unpack_temp_node],
            is_temp = 0,
            )

        return UtilNodes.LetNode(
            unpack_temp_node,
            self._transform_carray_iteration(
                node,
                ExprNodes.SliceIndexNode(
                    slice_node.pos,
                    base = slice_base_node,
                    start = None,
                    step = None,
                    stop = len_node,
                    type = slice_base_node.type,
                    is_temp = 1,
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                    ),
                reversed = reversed))
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    PyUnicode_READ_func_type = PyrexTypes.CFuncType(
        PyrexTypes.c_py_ucs4_type, [
            PyrexTypes.CFuncTypeArg("kind", PyrexTypes.c_int_type, None),
            PyrexTypes.CFuncTypeArg("data", PyrexTypes.c_void_ptr_type, None),
            PyrexTypes.CFuncTypeArg("index", PyrexTypes.c_py_ssize_t_type, None)
        ])

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    init_unicode_iteration_func_type = PyrexTypes.CFuncType(
        PyrexTypes.c_int_type, [
            PyrexTypes.CFuncTypeArg("s", PyrexTypes.py_object_type, None),
            PyrexTypes.CFuncTypeArg("length", PyrexTypes.c_py_ssize_t_ptr_type, None),
            PyrexTypes.CFuncTypeArg("data", PyrexTypes.c_void_ptr_ptr_type, None),
            PyrexTypes.CFuncTypeArg("kind", PyrexTypes.c_int_ptr_type, None)
        ],
        exception_value = '-1')
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    def _transform_unicode_iteration(self, node, slice_node, reversed=False):
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        if slice_node.is_literal:
            # try to reduce to byte iteration for plain Latin-1 strings
            try:
                bytes_value = BytesLiteral(slice_node.value.encode('latin1'))
            except UnicodeEncodeError:
                pass
            else:
                bytes_slice = ExprNodes.SliceIndexNode(
                    slice_node.pos,
                    base=ExprNodes.BytesNode(
                        slice_node.pos, value=bytes_value,
                        constant_result=bytes_value,
                        type=PyrexTypes.c_char_ptr_type).coerce_to(
                            PyrexTypes.c_uchar_ptr_type, self.current_env()),
                    start=None,
                    stop=ExprNodes.IntNode(
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                        slice_node.pos, value=str(len(bytes_value)),
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                        constant_result=len(bytes_value),
                        type=PyrexTypes.c_py_ssize_t_type),
                    type=Builtin.unicode_type,  # hint for Python conversion
                )
                return self._transform_carray_iteration(node, bytes_slice, reversed)

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        unpack_temp_node = UtilNodes.LetRefNode(
            slice_node.as_none_safe_node("'NoneType' is not iterable"))

        start_node = ExprNodes.IntNode(
            node.pos, value='0', constant_result=0, type=PyrexTypes.c_py_ssize_t_type)
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        length_temp = UtilNodes.TempHandle(PyrexTypes.c_py_ssize_t_type)
        end_node = length_temp.ref(node.pos)
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        if reversed:
            relation1, relation2 = '>', '>='
            start_node, end_node = end_node, start_node
        else:
            relation1, relation2 = '<=', '<'

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        kind_temp = UtilNodes.TempHandle(PyrexTypes.c_int_type)
        data_temp = UtilNodes.TempHandle(PyrexTypes.c_void_ptr_type)
        counter_temp = UtilNodes.TempHandle(PyrexTypes.c_py_ssize_t_type)
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        target_value = ExprNodes.PythonCapiCallNode(
            slice_node.pos, "__Pyx_PyUnicode_READ",
            self.PyUnicode_READ_func_type,
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            args = [kind_temp.ref(slice_node.pos),
                    data_temp.ref(slice_node.pos),
                    counter_temp.ref(node.target.pos)],
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            is_temp = False,
            )
        if target_value.type != node.target.type:
            target_value = target_value.coerce_to(node.target.type,
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                                                  self.current_env())
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        target_assign = Nodes.SingleAssignmentNode(
            pos = node.target.pos,
            lhs = node.target,
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            rhs = target_value)
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        body = Nodes.StatListNode(
            node.pos,
            stats = [target_assign, node.body])

        loop_node = Nodes.ForFromStatNode(
            node.pos,
            bound1=start_node, relation1=relation1,
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            target=counter_temp.ref(node.target.pos),
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            relation2=relation2, bound2=end_node,
            step=None, body=body,
            else_clause=node.else_clause,
            from_range=True)

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        setup_node = Nodes.ExprStatNode(
            node.pos,
            expr = ExprNodes.PythonCapiCallNode(
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                slice_node.pos, "__Pyx_init_unicode_iteration",
                self.init_unicode_iteration_func_type,
                args = [unpack_temp_node,
                        ExprNodes.AmpersandNode(slice_node.pos, operand=length_temp.ref(slice_node.pos),
                                                type=PyrexTypes.c_py_ssize_t_ptr_type),
                        ExprNodes.AmpersandNode(slice_node.pos, operand=data_temp.ref(slice_node.pos),
                                                type=PyrexTypes.c_void_ptr_ptr_type),
                        ExprNodes.AmpersandNode(slice_node.pos, operand=kind_temp.ref(slice_node.pos),
                                                type=PyrexTypes.c_int_ptr_type),
                        ],
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                is_temp = True,
                result_is_used = False,
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                utility_code=UtilityCode.load_cached("unicode_iter", "Optimize.c"),
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                ))
        return UtilNodes.LetNode(
            unpack_temp_node,
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            UtilNodes.TempsBlockNode(
                node.pos, temps=[counter_temp, length_temp, data_temp, kind_temp],
                body=Nodes.StatListNode(node.pos, stats=[setup_node, loop_node])))
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    def _transform_carray_iteration(self, node, slice_node, reversed=False):
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        neg_step = False
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        if isinstance(slice_node, ExprNodes.SliceIndexNode):
            slice_base = slice_node.base
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            start = filter_none_node(slice_node.start)
            stop = filter_none_node(slice_node.stop)
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            step = None
            if not stop:
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                if not slice_base.type.is_pyobject:
                    error(slice_node.pos, "C array iteration requires known end index")
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                return node
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        elif isinstance(slice_node, ExprNodes.IndexNode):
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            assert isinstance(slice_node.index, ExprNodes.SliceNode)
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            slice_base = slice_node.base
            index = slice_node.index
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            start = filter_none_node(index.start)
            stop = filter_none_node(index.stop)
            step = filter_none_node(index.step)
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            if step:
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                if not isinstance(step.constant_result, (int,long)) \
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                       or step.constant_result == 0 \
                       or step.constant_result > 0 and not stop \
                       or step.constant_result < 0 and not start:
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                    if not slice_base.type.is_pyobject:
                        error(step.pos, "C array iteration requires known step size and end index")
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                    return node
                else:
                    # step sign is handled internally by ForFromStatNode
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                    step_value = step.constant_result
                    if reversed:
                        step_value = -step_value
                    neg_step = step_value < 0
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                    step = ExprNodes.IntNode(step.pos, type=PyrexTypes.c_py_ssize_t_type,
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                                             value=str(abs(step_value)),
                                             constant_result=abs(step_value))
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        elif slice_node.type.is_array:
            if slice_node.type.size is None:
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                error(slice_node.pos, "C array iteration requires known end index")
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                return node
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            slice_base = slice_node
            start = None
            stop = ExprNodes.IntNode(
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                slice_node.pos, value=str(slice_node.type.size),
                type=PyrexTypes.c_py_ssize_t_type, constant_result=slice_node.type.size)
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            step = None
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        else:
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            if not slice_node.type.is_pyobject:
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                error(slice_node.pos, "C array iteration requires known end index")
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            return node

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        if start:
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            start = start.coerce_to(PyrexTypes.c_py_ssize_t_type, self.current_env())
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        if stop:
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            stop = stop.coerce_to(PyrexTypes.c_py_ssize_t_type, self.current_env())
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        if stop is None:
            if neg_step:
                stop = ExprNodes.IntNode(
                    slice_node.pos, value='-1', type=PyrexTypes.c_py_ssize_t_type, constant_result=-1)
            else:
                error(slice_node.pos, "C array iteration requires known step size and end index")
                return node
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        if reversed:
            if not start:
                start = ExprNodes.IntNode(slice_node.pos, value="0",  constant_result=0,
                                          type=PyrexTypes.c_py_ssize_t_type)
            # if step was provided, it was already negated above
            start, stop = stop, start

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        ptr_type = slice_base.type
        if ptr_type.is_array:
            ptr_type = ptr_type.element_ptr_type()
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        carray_ptr = slice_base.coerce_to_simple(self.current_env())
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        if start and start.constant_result != 0:
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            start_ptr_node = ExprNodes.AddNode(
                start.pos,
                operand1=carray_ptr,
                operator='+',
                operand2=start,
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                type=ptr_type)
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        else:
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            start_ptr_node = carray_ptr
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        if stop and stop.constant_result != 0:
            stop_ptr_node = ExprNodes.AddNode(
                stop.pos,
                operand1=ExprNodes.CloneNode(carray_ptr),
                operator='+',
                operand2=stop,
                type=ptr_type
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                ).coerce_to_simple(self.current_env())
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        else:
            stop_ptr_node = ExprNodes.CloneNode(carray_ptr)
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        counter = UtilNodes.TempHandle(ptr_type)
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        counter_temp = counter.ref(node.target.pos)

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        if slice_base.type.is_string and node.target.type.is_pyobject:
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            # special case: char* -> bytes/unicode
            if slice_node.type is Builtin.unicode_type:
                target_value = ExprNodes.CastNode(
                    ExprNodes.DereferenceNode(
                        node.target.pos, operand=counter_temp,
                        type=ptr_type.base_type),
                    PyrexTypes.c_py_ucs4_type).coerce_to(
                        node.target.type, self.current_env())
            else:
                # char* -> bytes coercion requires slicing, not indexing
                target_value = ExprNodes.SliceIndexNode(
                    node.target.pos,
                    start=ExprNodes.IntNode(node.target.pos, value='0',
                                            constant_result=0,
                                            type=PyrexTypes.c_int_type),
                    stop=ExprNodes.IntNode(node.target.pos, value='1',
                                           constant_result=1,
                                           type=PyrexTypes.c_int_type),
                    base=counter_temp,
                    type=Builtin.bytes_type,
                    is_temp=1)
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        elif node.target.type.is_ptr and not node.target.type.assignable_from(ptr_type.base_type):
            # Allow iteration with pointer target to avoid copy.
            target_value = counter_temp
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        else:
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            # TODO: can this safely be replaced with DereferenceNode() as above?
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            target_value = ExprNodes.IndexNode(
                node.target.pos,
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                index=ExprNodes.IntNode(node.target.pos, value='0',
                                        constant_result=0,
                                        type=PyrexTypes.c_int_type),
                base=counter_temp,
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                is_buffer_access=False,
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                type=ptr_type.base_type)
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        if target_value.type != node.target.type:
            target_value = target_value.coerce_to(node.target.type,
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                                                  self.current_env())
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        target_assign = Nodes.SingleAssignmentNode(
            pos = node.target.pos,
            lhs = node.target,
            rhs = target_value)

        body = Nodes.StatListNode(
            node.pos,
            stats = [target_assign, node.body])

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        relation1, relation2 = self._find_for_from_node_relations(neg_step, reversed)

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        for_node = Nodes.ForFromStatNode(
            node.pos,
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            bound1=start_ptr_node, relation1=relation1,
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            target=counter_temp,
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            relation2=relation2, bound2=stop_ptr_node,
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            step=step, body=body,
            else_clause=node.else_clause,
            from_range=True)

        return UtilNodes.TempsBlockNode(
            node.pos, temps=[counter],
            body=for_node)

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    def _transform_enumerate_iteration(self, node, enumerate_function):
        args = enumerate_function.arg_tuple.args
        if len(args) == 0:
            error(enumerate_function.pos,
                  "enumerate() requires an iterable argument")
            return node
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        elif len(args) > 2:
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            error(enumerate_function.pos,
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                  "enumerate() takes at most 2 arguments")
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            return node

        if not node.target.is_sequence_constructor:
            # leave this untouched for now
            return node
        targets = node.target.args
        if len(targets) != 2:
            # leave this untouched for now
            return node

        enumerate_target, iterable_target = targets
        counter_type = enumerate_target.type

        if not counter_type.is_pyobject and not counter_type.is_int:
            # nothing we can do here, I guess
            return node

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        if len(args) == 2:
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            start = unwrap_coerced_node(args[1]).coerce_to(counter_type, self.current_env())
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        else:
            start = ExprNodes.IntNode(enumerate_function.pos,
                                      value='0',
                                      type=counter_type,
                                      constant_result=0)
        temp = UtilNodes.LetRefNode(start)

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        inc_expression = ExprNodes.AddNode(
            enumerate_function.pos,
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            operand1 = temp,
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            operand2 = ExprNodes.IntNode(node.pos, value='1',
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                                         type=counter_type,
                                         constant_result=1),
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            operator = '+',
            type = counter_type,
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            #inplace = True,   # not worth using in-place operation for Py ints
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            is_temp = counter_type.is_pyobject
            )

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        loop_body = [
            Nodes.SingleAssignmentNode(
                pos = enumerate_target.pos,
                lhs = enumerate_target,
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                rhs = temp),
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            Nodes.SingleAssignmentNode(
                pos = enumerate_target.pos,
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                lhs = temp,
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                rhs = inc_expression)
            ]
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        if isinstance(node.body, Nodes.StatListNode):
            node.body.stats = loop_body + node.body.stats
        else:
            loop_body.append(node.body)
            node.body = Nodes.StatListNode(
                node.body.pos,
                stats = loop_body)
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        node.target = iterable_target
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        node.item = node.item.coerce_to(iterable_target.type, self.current_env())
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        node.iterator.sequence = args[0]
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        # recurse into loop to check for further optimisations
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        return UtilNodes.LetNode(temp, self._optimise_for_loop(node, node.iterator.sequence))
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    def _find_for_from_node_relations(self, neg_step_value, reversed):
        if reversed:
            if neg_step_value:
                return '<', '<='
            else:
                return '>', '>='
        else:
            if neg_step_value:
                return '>=', '>'
            else:
                return '<=', '<'
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    def _transform_range_iteration(self, node, range_function, reversed=False):
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        args = range_function.arg_tuple.args
        if len(args) < 3:
            step_pos = range_function.pos
            step_value = 1
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            step = ExprNodes.IntNode(step_pos, value='1',
                                     constant_result=1)
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        else:
            step = args[2]
            step_pos = step.pos
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            if not isinstance(step.constant_result, (int, long)):
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                # cannot determine step direction
                return node
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            step_value = step.constant_result
            if step_value == 0:
                # will lead to an error elsewhere
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                return node
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            if reversed and step_value not in (1, -1):
                # FIXME: currently broken - requires calculation of the correct bounds
                return node
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            if not isinstance(step, ExprNodes.IntNode):
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                step = ExprNodes.IntNode(step_pos, value=str(step_value),
                                         constant_result=step_value)
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        if len(args) == 1:
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            bound1 = ExprNodes.IntNode(range_function.pos, value='0',
                                       constant_result=0)
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            bound2 = args[0].coerce_to_integer(self.current_env())
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        else:
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            bound1 = args[0].coerce_to_integer(self.current_env())
            bound2 = args[1].coerce_to_integer(self.current_env())
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        relation1, relation2 = self._find_for_from_node_relations(step_value < 0, reversed)

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        if reversed:
            bound1, bound2 = bound2, bound1
            if step_value < 0:
                step_value = -step_value
        else:
            if step_value < 0:
                step_value = -step_value

        step.value = str(step_value)
        step.constant_result = step_value
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        step = step.coerce_to_integer(self.current_env())
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        if not bound2.is_literal:
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            # stop bound must be immutable => keep it in a temp var
            bound2_is_temp = True
            bound2 = UtilNodes.LetRefNode(bound2)
        else:
            bound2_is_temp = False

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        for_node = Nodes.ForFromStatNode(
            node.pos,
            target=node.target,
            bound1=bound1, relation1=relation1,
            relation2=relation2, bound2=bound2,
            step=step, body=node.body,
            else_clause=node.else_clause,
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            from_range=True)
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        if bound2_is_temp:
            for_node = UtilNodes.LetNode(bound2, for_node)

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        return for_node

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    def _transform_dict_iteration(self, node, dict_obj, method, keys, values):
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        temps = []
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        temp = UtilNodes.TempHandle(PyrexTypes.py_object_type)
        temps.append(temp)
        dict_temp = temp.ref(dict_obj.pos)
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        temp = UtilNodes.TempHandle(PyrexTypes.c_py_ssize_t_type)
        temps.append(temp)
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        pos_temp = temp.ref(node.pos)
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        key_target = value_target = tuple_target = None
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        if keys and values:
            if node.target.is_sequence_constructor:
                if len(node.target.args) == 2:
                    key_target, value_target = node.target.args
                else:
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                    # unusual case that may or may not lead to an error
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                    return node
            else:
                tuple_target = node.target
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        elif keys:
            key_target = node.target
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        else:
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            value_target = node.target
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        if isinstance(node.body, Nodes.StatListNode):
            body = node.body
        else:
            body = Nodes.StatListNode(pos = node.body.pos,
                                      stats = [node.body])

        # keep original length to guard against dict modification
        dict_len_temp = UtilNodes.TempHandle(PyrexTypes.c_py_ssize_t_type)
        temps.append(dict_len_temp)
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        dict_len_temp_addr = ExprNodes.AmpersandNode(
            node.pos, operand=dict_len_temp.ref(dict_obj.pos),
            type=PyrexTypes.c_ptr_type(dict_len_temp.type))
        temp = UtilNodes.TempHandle(PyrexTypes.c_int_type)
        temps.append(temp)
        is_dict_temp = temp.ref(node.pos)
        is_dict_temp_addr = ExprNodes.AmpersandNode(
            node.pos, operand=is_dict_temp,
            type=PyrexTypes.c_ptr_type(temp.type))

        iter_next_node = Nodes.DictIterationNextNode(
            dict_temp, dict_len_temp.ref(dict_obj.pos), pos_temp,
            key_target, value_target, tuple_target,
            is_dict_temp)
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        iter_next_node = iter_next_node.analyse_expressions(self.current_env())
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        body.stats[0:0] = [iter_next_node]

        if method:
            method_node = ExprNodes.StringNode(
                dict_obj.pos, is_identifier=True, value=method)
            dict_obj = dict_obj.as_none_safe_node(
                "'NoneType' object has no attribute '%s'",
                error = "PyExc_AttributeError",
                format_args = [method])
        else:
            method_node = ExprNodes.NullNode(dict_obj.pos)
            dict_obj = dict_obj.as_none_safe_node("'NoneType' object is not iterable")
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        def flag_node(value):
            value = value and 1 or 0
            return ExprNodes.IntNode(node.pos, value=str(value), constant_result=value)
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        result_code = [
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            Nodes.SingleAssignmentNode(
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                node.pos,
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                lhs = pos_temp,
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                rhs = ExprNodes.IntNode(node.pos, value='0',
                                        constant_result=0)),
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            Nodes.SingleAssignmentNode(
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                dict_obj.pos,
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                lhs = dict_temp,
                rhs = ExprNodes.PythonCapiCallNode(
                    dict_obj.pos,
                    "__Pyx_dict_iterator",
                    self.PyDict_Iterator_func_type,
                    utility_code = UtilityCode.load_cached("dict_iter", "Optimize.c"),
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                    args = [dict_obj, flag_node(dict_obj.type is Builtin.dict_type),
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                            method_node, dict_len_temp_addr, is_dict_temp_addr,
                            ],
                    is_temp=True,
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                )),
            Nodes.WhileStatNode(
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                node.pos,
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                condition = None,
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                body = body,
                else_clause = node.else_clause
                )
            ]

        return UtilNodes.TempsBlockNode(
            node.pos, temps=temps,
            body=Nodes.StatListNode(
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                node.pos,
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                stats = result_code
                ))

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    PyDict_Iterator_func_type = PyrexTypes.CFuncType(
        PyrexTypes.py_object_type, [
            PyrexTypes.CFuncTypeArg("dict",  PyrexTypes.py_object_type, None),
            PyrexTypes.CFuncTypeArg("is_dict",  PyrexTypes.c_int_type, None),
            PyrexTypes.CFuncTypeArg("method_name",  PyrexTypes.py_object_type, None),
            PyrexTypes.CFuncTypeArg("p_orig_length",  PyrexTypes.c_py_ssize_t_ptr_type, None),
            PyrexTypes.CFuncTypeArg("p_is_dict",  PyrexTypes.c_int_ptr_type, None),
            ])

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class SwitchTransform(Visitor.CythonTransform):
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    """
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    This transformation tries to turn long if statements into C switch statements.
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    The requirement is that every clause be an (or of) var == value, where the var
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    is common among all clauses and both var and value are ints.
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    """
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    NO_MATCH = (None, None, None)

    def extract_conditions(self, cond, allow_not_in):
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        while True:
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            if isinstance(cond, (ExprNodes.CoerceToTempNode,
                                 ExprNodes.CoerceToBooleanNode)):
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                cond = cond.arg
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            elif isinstance(cond, ExprNodes.BoolBinopResultNode):
                cond = cond.arg.arg
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            elif isinstance(cond, UtilNodes.EvalWithTempExprNode):
                # this is what we get from the FlattenInListTransform
                cond = cond.subexpression
            elif isinstance(cond, ExprNodes.TypecastNode):
                cond = cond.operand
            else:
                break
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        if isinstance(cond, ExprNodes.PrimaryCmpNode):
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            if cond.cascade is not None:
                return self.NO_MATCH
            elif cond.is_c_string_contains() and \
                   isinstance(cond.operand2, (ExprNodes.UnicodeNode, ExprNodes.BytesNode)):
                not_in = cond.operator == 'not_in'
                if not_in and not allow_not_in:
                    return self.NO_MATCH
                if isinstance(cond.operand2, ExprNodes.UnicodeNode) and \
                       cond.operand2.contains_surrogates():
                    # dealing with surrogates leads to different
                    # behaviour on wide and narrow Unicode
                    # platforms => refuse to optimise this case
                    return self.NO_MATCH
                return not_in, cond.operand1, self.extract_in_string_conditions(cond.operand2)
            elif not cond.is_python_comparison():
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                if cond.operator == '==':
                    not_in = False
                elif allow_not_in and cond.operator == '!=':
                    not_in = True
                else:
                    return self.NO_MATCH
                # this looks somewhat silly, but it does the right
                # checks for NameNode and AttributeNode
                if is_common_value(cond.operand1, cond.operand1):
                    if cond.operand2.is_literal:
                        return not_in, cond.operand1, [cond.operand2]
                    elif getattr(cond.operand2, 'entry', None) \
                             and cond.operand2.entry.is_const:
                        return not_in, cond.operand1, [cond.operand2]
                if is_common_value(cond.operand2, cond.operand2):
                    if cond.operand1.is_literal:
                        return not_in, cond.operand2, [cond.operand1]
                    elif getattr(cond.operand1, 'entry', None) \
                             and cond.operand1.entry.is_const:
                        return not_in, cond.operand2, [cond.operand1]
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        elif isinstance(cond, (ExprNodes.BoolBinopNode, ExprNodes.GenericBoolBinopNode)):
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            if cond.operator == 'or' or (allow_not_in and cond.operator == 'and'):
                allow_not_in = (cond.operator == 'and')
                not_in_1, t1, c1 = self.extract_conditions(cond.operand1, allow_not_in)
                not_in_2, t2, c2 = self.extract_conditions(cond.operand2, allow_not_in)
                if t1 is not None and not_in_1 == not_in_2 and is_common_value(t1, t2):
                    if (not not_in_1) or allow_not_in:
                        return not_in_1, t1, c1+c2
        return self.NO_MATCH

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    def extract_in_string_conditions(self, string_literal):
        if isinstance(string_literal, ExprNodes.UnicodeNode):
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            charvals = list(map(ord, set(string_literal.value)))
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            charvals.sort()
            return [ ExprNodes.IntNode(string_literal.pos, value=str(charval),
                                       constant_result=charval)
                     for charval in charvals ]
        else:
            # this is a bit tricky as Py3's bytes type returns
            # integers on iteration, whereas Py2 returns 1-char byte
            # strings
            characters = string_literal.value
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            characters = list(set([ characters[i:i+1] for i in range(len(characters)) ]))
            characters.sort()
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            return [ ExprNodes.CharNode(string_literal.pos, value=charval,
                                        constant_result=charval)
                     for charval in characters ]

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    def extract_common_conditions(self, common_var, condition, allow_not_in):
        not_in, var, conditions = self.extract_conditions(condition, allow_not_in)
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        if var is None:
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            return self.NO_MATCH
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        elif common_var is not None and not is_common_value(var, common_var):
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            return self.NO_MATCH
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        elif not (var.type.is_int or var.type.is_enum) or sum([not (cond.type.is_int or cond.type.is_enum) for cond in conditions]):
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            return self.NO_MATCH
        return not_in, var, conditions

    def has_duplicate_values(self, condition_values):
        # duplicated values don't work in a switch statement
        seen = set()
        for value in condition_values:
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            if value.has_constant_result():
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                if value.constant_result in seen:
                    return True
                seen.add(value.constant_result)
            else:
                # this isn't completely safe as we don't know the
                # final C value, but this is about the best we can do
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                try:
                    if value.entry.cname in seen:
                        return True
                except AttributeError:
                    return True  # play safe
                seen.add(value.entry.cname)
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        return False
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    def visit_IfStatNode(self, node):
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        if not self.current_directives.get('optimize.use_switch'):
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            self.visitchildren(node)
            return node

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        common_var = None
        cases = []
        for if_clause in node.if_clauses:
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            _, common_var, conditions = self.extract_common_conditions(
                common_var, if_clause.condition, False)
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            if common_var is None:
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                self.visitchildren(node)
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                return node
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            cases.append(Nodes.SwitchCaseNode(pos = if_clause.pos,
                                              conditions = conditions,
                                              body = if_clause.body))

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        condition_values = [
            cond for case in cases for cond in case.conditions]
        if len(condition_values) < 2:
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            self.visitchildren(node)
            return node
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        if self.has_duplicate_values(condition_values):
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            self.visitchildren(node)
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            return node
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        common_var = unwrap_node(common_var)
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        switch_node = Nodes.SwitchStatNode(pos = node.pos,
                                           test = common_var,
                                           cases = cases,
                                           else_clause = node.else_clause)
        return switch_node

    def visit_CondExprNode(self, node):
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        if not self.current_directives.get('optimize.use_switch'):
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            self.visitchildren(node)
            return node

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        not_in, common_var, conditions = self.extract_common_conditions(
            None, node.test, True)
        if common_var is None \
               or len(conditions) < 2 \
               or self.has_duplicate_values(conditions):
            self.visitchildren(node)
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            return node
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        return self.build_simple_switch_statement(
            node, common_var, conditions, not_in,
            node.true_val, node.false_val)
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    def visit_BoolBinopNode(self, node):
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        if not self.current_directives.get('optimize.use_switch'):
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            self.visitchildren(node)
            return node

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        not_in, common_var, conditions = self.extract_common_conditions(
            None, node, True)
        if common_var is None \
               or len(conditions) < 2 \
               or self.has_duplicate_values(conditions):
            self.visitchildren(node)
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            return node

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        return self.build_simple_switch_statement(
            node, common_var, conditions, not_in,
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            ExprNodes.BoolNode(node.pos, value=True, constant_result=True),
            ExprNodes.BoolNode(node.pos, value=False, constant_result=False))

    def visit_PrimaryCmpNode(self, node):
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        if not self.current_directives.get('optimize.use_switch'):
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            self.visitchildren(node)
            return node

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        not_in, common_var, conditions = self.extract_common_conditions(
            None, node, True)
        if common_var is None \
               or len(conditions) < 2 \
               or self.has_duplicate_values(conditions):
            self.visitchildren(node)
            return node

        return self.build_simple_switch_statement(
            node, common_var, conditions, not_in,
            ExprNodes.BoolNode(node.pos, value=True, constant_result=True),
            ExprNodes.BoolNode(node.pos, value=False, constant_result=False))
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    def build_simple_switch_statement(self, node, common_var, conditions,
                                      not_in, true_val, false_val):
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        result_ref = UtilNodes.ResultRefNode(node)
        true_body = Nodes.SingleAssignmentNode(
            node.pos,
            lhs = result_ref,
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            rhs = true_val,
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            first = True)
        false_body = Nodes.SingleAssignmentNode(
            node.pos,
            lhs = result_ref,
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            rhs = false_val,
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            first = True)

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        if not_in:
            true_body, false_body = false_body, true_body

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        cases = [Nodes.SwitchCaseNode(pos = node.pos,
                                      conditions = conditions,
                                      body = true_body)]

        common_var = unwrap_node(common_var)
        switch_node = Nodes.SwitchStatNode(pos = node.pos,
                                           test = common_var,
                                           cases = cases,
                                           else_clause = false_body)
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        replacement = UtilNodes.TempResultFromStatNode(result_ref, switch_node)
        return replacement

    def visit_EvalWithTempExprNode(self, node):
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        if not self.current_directives.get('optimize.use_switch'):
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            self.visitchildren(node)
            return node

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        # drop unused expression temp from FlattenInListTransform
        orig_expr = node.subexpression
        temp_ref = node.lazy_temp
        self.visitchildren(node)
        if node.subexpression is not orig_expr:
            # node was restructured => check if temp is still used
            if not Visitor.tree_contains(node.subexpression, temp_ref):
                return node.subexpression
        return node
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    visit_Node = Visitor.VisitorTransform.recurse_to_children
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class FlattenInListTransform(Visitor.VisitorTransform, SkipDeclarations):
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    """
    This transformation flattens "x in [val1, ..., valn]" into a sequential list
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    of comparisons.
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    """
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    def visit_PrimaryCmpNode(self, node):
        self.visitchildren(node)
        if node.cascade is not None:
            return node
        elif node.operator == 'in':
            conjunction = 'or'
            eq_or_neq = '=='
        elif node.operator == 'not_in':
            conjunction = 'and'
            eq_or_neq = '!='
        else:
            return node
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        if not isinstance(node.operand2, (ExprNodes.TupleNode,
                                          ExprNodes.ListNode,
                                          ExprNodes.SetNode)):
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            return node
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        args = node.operand2.args
        if len(args) == 0:
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            # note: lhs may have side effects
            return node
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        lhs = UtilNodes.ResultRefNode(node.operand1)
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        conds = []
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        temps = []
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        for arg in args:
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            try:
                # Trial optimisation to avoid redundant temp
                # assignments.  However, since is_simple() is meant to
                # be called after type analysis, we ignore any errors
                # and just play safe in that case.
                is_simple_arg = arg.is_simple()
            except Exception:
                is_simple_arg = False
            if not is_simple_arg:
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                # must evaluate all non-simple RHS before doing the comparisons
                arg = UtilNodes.LetRefNode(arg)
                temps.append(arg)
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            cond = ExprNodes.PrimaryCmpNode(
                                pos = node.pos,
                                operand1 = lhs,
                                operator = eq_or_neq,
                                operand2 = arg,
                                cascade = None)
            conds.append(ExprNodes.TypecastNode(
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                                pos = node.pos,
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                                operand = cond,
                                type = PyrexTypes.c_bint_type))
        def concat(left, right):
            return ExprNodes.BoolBinopNode(
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                                pos = node.pos,
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                                operator = conjunction,
                                operand1 = left,
                                operand2 = right)

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        condition = reduce(concat, conds)
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        new_node = UtilNodes.EvalWithTempExprNode(lhs, condition)
        for temp in temps[::-1]:
            new_node = UtilNodes.EvalWithTempExprNode(temp, new_node)
        return new_node
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    visit_Node = Visitor.VisitorTransform.recurse_to_children
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class DropRefcountingTransform(Visitor.VisitorTransform):
    """Drop ref-counting in safe places.
    """
    visit_Node = Visitor.VisitorTransform.recurse_to_children

    def visit_ParallelAssignmentNode(self, node):
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        """
        Parallel swap assignments like 'a,b = b,a' are safe.
        """
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        left_names, right_names = [], []
        left_indices, right_indices = [], []
        temps = []

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        for stat in node.stats:
            if isinstance(stat, Nodes.SingleAssignmentNode):
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                if not self._extract_operand(stat.lhs, left_names,
                                             left_indices, temps):
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                    return node
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                if not self._extract_operand(stat.rhs, right_names,
                                             right_indices, temps):
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                    return node
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            elif isinstance(stat, Nodes.CascadedAssignmentNode):
                # FIXME
                return node
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            else:
                return node

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        if left_names or right_names:
            # lhs/rhs names must be a non-redundant permutation
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            lnames = [ path for path, n in left_names ]
            rnames = [ path for path, n in right_names ]
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            if set(lnames) != set(rnames):
                return node
            if len(set(lnames)) != len(right_names):
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                return node

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        if left_indices or right_indices:
            # base name and index of index nodes must be a
            # non-redundant permutation
            lindices = []
            for lhs_node in left_indices:
                index_id = self._extract_index_id(lhs_node)
                if not index_id:
                    return node
                lindices.append(index_id)
            rindices = []
            for rhs_node in right_indices:
                index_id = self._extract_index_id(rhs_node)
                if not index_id:
                    return node
                rindices.append(index_id)
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            if set(lindices) != set(rindices):
                return node
            if len(set(lindices)) != len(right_indices):
                return node

            # really supporting IndexNode requires support in
            # __Pyx_GetItemInt(), so let's stop short for now
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            return node

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        temp_args = [t.arg for t in temps]
        for temp in temps:
            temp.use_managed_ref = False

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        for _, name_node in left_names + right_names:
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            if name_node not in temp_args:
                name_node.use_managed_ref = False

        for index_node in left_indices + right_indices:
            index_node.use_managed_ref = False
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        return node

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    def _extract_operand(self, node, names, indices, temps):
        node = unwrap_node(node)
        if not node.type.is_pyobject:
            return False
        if isinstance(node, ExprNodes.CoerceToTempNode):
            temps.append(node)
            node = node.arg
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        name_path = []
        obj_node = node
        while isinstance(obj_node, ExprNodes.AttributeNode):
            if obj_node.is_py_attr:
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                return False
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            name_path.append(obj_node.member)
            obj_node = obj_node.obj
        if isinstance(obj_node, ExprNodes.NameNode):
            name_path.append(obj_node.name)
            names.append( ('.'.join(name_path[::-1]), node) )
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        elif isinstance(node, ExprNodes.IndexNode):
            if node.base.type != Builtin.list_type:
                return False
            if not node.index.type.is_int:
                return False
            if not isinstance(node.base, ExprNodes.NameNode):
                return False
            indices.append(node)
        else:
            return False
        return True

    def _extract_index_id(self, index_node):
        base = index_node.base
        index = index_node.index
        if isinstance(index, ExprNodes.NameNode):
            index_val = index.name
        elif isinstance(index, ExprNodes.ConstNode):
            # FIXME:
            return None
        else:
            return None
        return (base.name, index_val)

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class EarlyReplaceBuiltinCalls(Visitor.EnvTransform):
    """Optimize some common calls to builtin types *before* the type
    analysis phase and *after* the declarations analysis phase.

    This transform cannot make use of any argument types, but it can
    restructure the tree in a way that the type analysis phase can
    respond to.
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    Introducing C function calls here may not be a good idea.  Move
    them to the OptimizeBuiltinCalls transform instead, which runs
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    after type analysis.
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    """
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    # only intercept on call nodes
    visit_Node = Visitor.VisitorTransform.recurse_to_children
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    def visit_SimpleCallNode(self, node):
        self.visitchildren(node)
        function = node.function
        if not self._function_is_builtin_name(function):
            return node
        return self._dispatch_to_handler(node, function, node.args)

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    def visit_GeneralCallNode(self, node):
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        self.visitchildren(node)
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        function = node.function
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        if not self._function_is_builtin_name(function):
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            return node
        arg_tuple = node.positional_args
        if not isinstance(arg_tuple, ExprNodes.TupleNode):
            return node
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        args = arg_tuple.args
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        return self._dispatch_to_handler(
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            node, function, args, node.keyword_args)
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    def _function_is_builtin_name(self, function):
        if not function.is_name:
            return False
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        env = self.current_env()
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        entry = env.lookup(function.name)
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        if entry is not env.builtin_scope().lookup_here(function.name):
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            return False
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        # if entry is None, it's at least an undeclared name, so likely builtin
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        return True

    def _dispatch_to_handler(self, node, function, args, kwargs=None):
        if kwargs is None:
            handler_name = '_handle_simple_function_%s' % function.name
        else:
            handler_name = '_handle_general_function_%s' % function.name
        handle_call = getattr(self, handler_name, None)
        if handle_call is not None:
            if kwargs is None:
                return handle_call(node, args)
            else:
                return handle_call(node, args, kwargs)
        return node

    def _inject_capi_function(self, node, cname, func_type, utility_code=None):
        node.function = ExprNodes.PythonCapiFunctionNode(
            node.function.pos, node.function.name, cname, func_type,
            utility_code = utility_code)

    def _error_wrong_arg_count(self, function_name, node, args, expected=None):
        if not expected: # None or 0
            arg_str = ''
        elif isinstance(expected, basestring) or expected > 1:
            arg_str = '...'
        elif expected == 1:
            arg_str = 'x'
        else:
            arg_str = ''
        if expected is not None:
            expected_str = 'expected %s, ' % expected
        else:
            expected_str = ''
        error(node.pos, "%s(%s) called with wrong number of args, %sfound %d" % (
            function_name, arg_str, expected_str, len(args)))

    # specific handlers for simple call nodes

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    def _handle_simple_function_float(self, node, pos_args):
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        if not pos_args:
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            return ExprNodes.FloatNode(node.pos, value='0.0')
        if len(pos_args) > 1:
            self._error_wrong_arg_count('float', node, pos_args, 1)
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        arg_type = getattr(pos_args[0], 'type', None)
        if arg_type in (PyrexTypes.c_double_type, Builtin.float_type):
            return pos_args[0]
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        return node

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    def _handle_simple_function_slice(self, node, pos_args):
        arg_count = len(pos_args)
        start = step = None
        if arg_count == 1:
            stop, = pos_args
        elif arg_count == 2:
            start, stop = pos_args
        elif arg_count == 3:
            start, stop, step = pos_args
        else:
            self._error_wrong_arg_count('slice', node, pos_args)
            return node
        return ExprNodes.SliceNode(
            node.pos,
            start=start or ExprNodes.NoneNode(node.pos),
            stop=stop,
            step=step or ExprNodes.NoneNode(node.pos))

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    class YieldNodeCollector(Visitor.TreeVisitor):
        def __init__(self):
            Visitor.TreeVisitor.__init__(self)
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            self.yield_stat_nodes = {}
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            self.yield_nodes = []

        visit_Node = Visitor.TreeVisitor.visitchildren
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        # XXX: disable inlining while it's not back supported
        def __visit_YieldExprNode(self, node):
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            self.yield_nodes.append(node)
            self.visitchildren(node)

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        def __visit_ExprStatNode(self, node):
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            self.visitchildren(node)
            if node.expr in self.yield_nodes:
                self.yield_stat_nodes[node.expr] = node

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        def __visit_GeneratorExpressionNode(self, node):
            # enable when we support generic generator expressions
            #
            # everything below this node is out of scope
            pass

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    def _find_single_yield_expression(self, node):
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        collector = self.YieldNodeCollector()
        collector.visitchildren(node)
        if len(collector.yield_nodes) != 1:
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            return None, None
        yield_node = collector.yield_nodes[0]
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        try:
            return (yield_node.arg, collector.yield_stat_nodes[yield_node])
        except KeyError:
            return None, None
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    def _handle_simple_function_all(self, node, pos_args):
        """Transform

        _result = all(x for L in LL for x in L)

        into

        for L in LL:
            for x in L:
                if not x:
                    _result = False
                    break
            else:
                continue
            break
        else:
            _result = True
        """
        return self._transform_any_all(node, pos_args, False)

    def _handle_simple_function_any(self, node, pos_args):
        """Transform

        _result = any(x for L in LL for x in L)

        into

        for L in LL:
            for x in L:
                if x:
                    _result = True
                    break
            else:
                continue
            break
        else:
            _result = False
        """
        return self._transform_any_all(node, pos_args, True)

    def _transform_any_all(self, node, pos_args, is_any):
        if len(pos_args) != 1:
            return node
        if not isinstance(pos_args[0], ExprNodes.GeneratorExpressionNode):
            return node
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        gen_expr_node = pos_args[0]
        loop_node = gen_expr_node.loop
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        yield_expression, yield_stat_node = self._find_single_yield_expression(loop_node)
        if yield_expression is None:
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            return node

        if is_any:
            condition = yield_expression
        else:
            condition = ExprNodes.NotNode(yield_expression.pos, operand = yield_expression)

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        result_ref = UtilNodes.ResultRefNode(pos=node.pos, type=PyrexTypes.c_bint_type)
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        test_node = Nodes.IfStatNode(
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            yield_expression.pos,
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            else_clause = None,
            if_clauses = [ Nodes.IfClauseNode(
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                yield_expression.pos,
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                condition = condition,
                body = Nodes.StatListNode(
                    node.pos,
                    stats = [
                        Nodes.SingleAssignmentNode(
                            node.pos,
                            lhs = result_ref,
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                            rhs = ExprNodes.BoolNode(yield_expression.pos, value = is_any,
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                                                     constant_result = is_any)),
                        Nodes.BreakStatNode(node.pos)
                        ])) ]
            )
        loop = loop_node
        while isinstance(loop.body, Nodes.LoopNode):
            next_loop = loop.body
            loop.body = Nodes.StatListNode(loop.body.pos, stats = [
                loop.body,
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                Nodes.BreakStatNode(yield_expression.pos)
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                ])
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            next_loop.else_clause = Nodes.ContinueStatNode(yield_expression.pos)
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            loop = next_loop
        loop_node.else_clause = Nodes.SingleAssignmentNode(
            node.pos,
            lhs = result_ref,
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            rhs = ExprNodes.BoolNode(yield_expression.pos, value = not is_any,
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                                     constant_result = not is_any))

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        Visitor.recursively_replace_node(loop_node, yield_stat_node, test_node)
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        return ExprNodes.InlinedGeneratorExpressionNode(
            gen_expr_node.pos, loop = loop_node, result_node = result_ref,
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            expr_scope = gen_expr_node.expr_scope, orig_func = is_any and 'any' or 'all')
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    def _handle_simple_function_sorted(self, node, pos_args):
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        """Transform sorted(genexpr) and sorted([listcomp]) into
        [listcomp].sort().  CPython just reads the iterable into a
        list and calls .sort() on it.  Expanding the iterable in a
        listcomp is still faster and the result can be sorted in
        place.
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        """
        if len(pos_args) != 1:
            return node
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        if isinstance(pos_args[0], ExprNodes.ComprehensionNode) \
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               and pos_args[0].type is Builtin.list_type:
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            listcomp_node = pos_args[0]
            loop_node = listcomp_node.loop
        elif isinstance(pos_args[0], ExprNodes.GeneratorExpressionNode):
            gen_expr_node = pos_args[0]
            loop_node = gen_expr_node.loop
            yield_expression, yield_stat_node = self._find_single_yield_expression(loop_node)
            if yield_expression is None:
                return node
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            append_node = ExprNodes.ComprehensionAppendNode(
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                yield_expression.pos, expr = yield_expression)
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            Visitor.recursively_replace_node(loop_node, yield_stat_node, append_node)
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            listcomp_node = ExprNodes.ComprehensionNode(
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                gen_expr_node.pos, loop = loop_node,
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                append = append_node, type = Builtin.list_type,
                expr_scope = gen_expr_node.expr_scope,
                has_local_scope = True)
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            append_node.target = listcomp_node
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        else:
            return node
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        result_node = UtilNodes.ResultRefNode(
            pos = loop_node.pos, type = Builtin.list_type, may_hold_none=False)
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        listcomp_assign_node = Nodes.SingleAssignmentNode(
            node.pos, lhs = result_node, rhs = listcomp_node, first = True)

        sort_method = ExprNodes.AttributeNode(
            node.pos, obj = result_node, attribute = EncodedString('sort'),
            # entry ? type ?
            needs_none_check = False)
        sort_node = Nodes.ExprStatNode(
            node.pos, expr = ExprNodes.SimpleCallNode(
                node.pos, function = sort_method, args = []))

        sort_node.analyse_declarations(self.current_env())

        return UtilNodes.TempResultFromStatNode(
            result_node,
            Nodes.StatListNode(node.pos, stats = [ listcomp_assign_node, sort_node ]))

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    def _handle_simple_function_sum(self, node, pos_args):
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        """Transform sum(genexpr) into an equivalent inlined aggregation loop.
        """
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        if len(pos_args) not in (1,2):
            return node
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        if not isinstance(pos_args[0], (ExprNodes.GeneratorExpressionNode,
                                        ExprNodes.ComprehensionNode)):
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            return node
        gen_expr_node = pos_args[0]
        loop_node = gen_expr_node.loop

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        if isinstance(gen_expr_node, ExprNodes.GeneratorExpressionNode):
            yield_expression, yield_stat_node = self._find_single_yield_expression(loop_node)
            if yield_expression is None:
                return node
        else: # ComprehensionNode
            yield_stat_node = gen_expr_node.append
            yield_expression = yield_stat_node.expr
            try:
                if not yield_expression.is_literal or not yield_expression.type.is_int:
                    return node
            except AttributeError:
                return node # in case we don't have a type yet
            # special case: old Py2 backwards compatible "sum([int_const for ...])"
            # can safely be unpacked into a genexpr
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        if len(pos_args) == 1:
            start = ExprNodes.IntNode(node.pos, value='0', constant_result=0)
        else:
            start = pos_args[1]

        result_ref = UtilNodes.ResultRefNode(pos=node.pos, type=PyrexTypes.py_object_type)
        add_node = Nodes.SingleAssignmentNode(
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            yield_expression.pos,
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            lhs = result_ref,
            rhs = ExprNodes.binop_node(node.pos, '+', result_ref, yield_expression)
            )

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        Visitor.recursively_replace_node(loop_node, yield_stat_node, add_node)
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        exec_code = Nodes.StatListNode(
            node.pos,
            stats = [
                Nodes.SingleAssignmentNode(
                    start.pos,
                    lhs = UtilNodes.ResultRefNode(pos=node.pos, expression=result_ref),
                    rhs = start,
                    first = True),
                loop_node
                ])

        return ExprNodes.InlinedGeneratorExpressionNode(
            gen_expr_node.pos, loop = exec_code, result_node = result_ref,
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            expr_scope = gen_expr_node.expr_scope, orig_func = 'sum',
            has_local_scope = gen_expr_node.has_local_scope)
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    def _handle_simple_function_min(self, node, pos_args):
        return self._optimise_min_max(node, pos_args, '<')

    def _handle_simple_function_max(self, node, pos_args):
        return self._optimise_min_max(node, pos_args, '>')

    def _optimise_min_max(self, node, args, operator):
        """Replace min(a,b,...) and max(a,b,...) by explicit comparison code.
        """
        if len(args) <= 1:
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            if len(args) == 1 and args[0].is_sequence_constructor:
                args = args[0].args
            else:
                # leave this to Python
                return node
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        cascaded_nodes = list(map(UtilNodes.ResultRefNode, args[1:]))
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        last_result = args[0]
        for arg_node in cascaded_nodes:
            result_ref = UtilNodes.ResultRefNode(last_result)
            last_result = ExprNodes.CondExprNode(
                arg_node.pos,
                true_val = arg_node,
                false_val = result_ref,
                test = ExprNodes.PrimaryCmpNode(
                    arg_node.pos,
                    operand1 = arg_node,
                    operator = operator,
                    operand2 = result_ref,
                    )
                )
            last_result = UtilNodes.EvalWithTempExprNode(result_ref, last_result)

        for ref_node in cascaded_nodes[::-1]:
            last_result = UtilNodes.EvalWithTempExprNode(ref_node, last_result)

        return last_result

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    def _DISABLED_handle_simple_function_tuple(self, node, pos_args):
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        if not pos_args:
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            return ExprNodes.TupleNode(node.pos, args=[], constant_result=())
        # This is a bit special - for iterables (including genexps),
        # Python actually overallocates and resizes a newly created
        # tuple incrementally while reading items, which we can't
        # easily do without explicit node support. Instead, we read
        # the items into a list and then copy them into a tuple of the
        # final size.  This takes up to twice as much memory, but will
        # have to do until we have real support for genexps.
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        result = self._transform_list_set_genexpr(node, pos_args, Builtin.list_type)
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        if result is not node:
            return ExprNodes.AsTupleNode(node.pos, arg=result)
        return node

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    def _handle_simple_function_frozenset(self, node, pos_args):
        """Replace frozenset([...]) by frozenset((...)) as tuples are more efficient.
        """
        if len(pos_args) != 1:
            return node
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        if pos_args[0].is_sequence_constructor and not pos_args[0].args:
            del pos_args[0]
        elif isinstance(pos_args[0], ExprNodes.ListNode):
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            pos_args[0] = pos_args[0].as_tuple()
        return node

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    def _handle_simple_function_list(self, node, pos_args):
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        if not pos_args:
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            return ExprNodes.ListNode(node.pos, args=[], constant_result=[])
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        return self._transform_list_set_genexpr(node, pos_args, Builtin.list_type)
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    def _handle_simple_function_set(self, node, pos_args):
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        if not pos_args:
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            return ExprNodes.SetNode(node.pos, args=[], constant_result=set())
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        return self._transform_list_set_genexpr(node, pos_args, Builtin.set_type)
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    def _transform_list_set_genexpr(self, node, pos_args, target_type):
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        """Replace set(genexpr) and list(genexpr) by a literal comprehension.
        """
        if len(pos_args) > 1:
            return node
        if not isinstance(pos_args[0], ExprNodes.GeneratorExpressionNode):
            return node
        gen_expr_node = pos_args[0]
        loop_node = gen_expr_node.loop

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        yield_expression, yield_stat_node = self._find_single_yield_expression(loop_node)
        if yield_expression is None:
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            return node

        append_node = ExprNodes.ComprehensionAppendNode(
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            yield_expression.pos,
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            expr = yield_expression)
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        Visitor.recursively_replace_node(loop_node, yield_stat_node, append_node)
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        comp = ExprNodes.ComprehensionNode(
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            node.pos,
            has_local_scope = True,
            expr_scope = gen_expr_node.expr_scope,
            loop = loop_node,
            append = append_node,
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            type = target_type)
        append_node.target = comp
        return comp
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    def _handle_simple_function_dict(self, node, pos_args):
        """Replace dict( (a,b) for ... ) by a literal { a:b for ... }.
        """
        if len(pos_args) == 0:
            return ExprNodes.DictNode(node.pos, key_value_pairs=[], constant_result={})
        if len(pos_args) > 1:
            return node
        if not isinstance(pos_args[0], ExprNodes.GeneratorExpressionNode):
            return node
        gen_expr_node = pos_args[0]
        loop_node = gen_expr_node.loop

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        yield_expression, yield_stat_node = self._find_single_yield_expression(loop_node)
        if yield_expression is None:
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            return node

        if not isinstance(yield_expression, ExprNodes.TupleNode):
            return node
        if len(yield_expression.args) != 2:
            return node

        append_node = ExprNodes.DictComprehensionAppendNode(
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            yield_expression.pos,
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            key_expr = yield_expression.args[0],
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            value_expr = yield_expression.args[1])
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        Visitor.recursively_replace_node(loop_node, yield_stat_node, append_node)
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        dictcomp = ExprNodes.ComprehensionNode(
            node.pos,
            has_local_scope = True,
            expr_scope = gen_expr_node.expr_scope,
            loop = loop_node,
            append = append_node,
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            type = Builtin.dict_type)
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        append_node.target = dictcomp
        return dictcomp

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    # specific handlers for general call nodes

    def _handle_general_function_dict(self, node, pos_args, kwargs):
        """Replace dict(a=b,c=d,...) by the underlying keyword dict
        construction which is done anyway.
        """
        if len(pos_args) > 0:
            return node
        if not isinstance(kwargs, ExprNodes.DictNode):
            return node
        return kwargs

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class InlineDefNodeCalls(Visitor.NodeRefCleanupMixin, Visitor.EnvTransform):
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    visit_Node = Visitor.VisitorTransform.recurse_to_children

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    def get_constant_value_node(self, name_node):
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        if name_node.cf_state is None:
            return None
        if name_node.cf_state.cf_is_null:
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            return None
        entry = self.current_env().lookup(name_node.name)
        if not entry or (not entry.cf_assignments
                         or len(entry.cf_assignments) != 1):
            # not just a single assignment in all closures
            return None
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        return entry.cf_assignments[0].rhs
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    def visit_SimpleCallNode(self, node):
        self.visitchildren(node)
        if not self.current_directives.get('optimize.inline_defnode_calls'):
            return node
        function_name = node.function
        if not function_name.is_name:
            return node
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        function = self.get_constant_value_node(function_name)
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        if not isinstance(function, ExprNodes.PyCFunctionNode):
            return node
        inlined = ExprNodes.InlinedDefNodeCallNode(
            node.pos, function_name=function_name,
            function=function, args=node.args)
        if inlined.can_be_inlined():
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            return self.replace(node, inlined)
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        return node

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class OptimizeBuiltinCalls(Visitor.MethodDispatcherTransform):
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    """Optimize some common methods calls and instantiation patterns
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    for builtin types *after* the type analysis phase.

    Running after type analysis, this transform can only perform
    function replacements that do not alter the function return type
    in a way that was not anticipated by the type analysis.
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    """
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    ### cleanup to avoid redundant coercions to/from Python types

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    def _visit_PyTypeTestNode(self, node):
        # disabled - appears to break assignments in some cases, and
        # also drops a None check, which might still be required
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        """Flatten redundant type checks after tree changes.
        """
        old_arg = node.arg
        self.visitchildren(node)
        if old_arg is node.arg or node.arg.type != node.type:
            return node
        return node.arg

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    def _visit_TypecastNode(self, node):
        # disabled - the user may have had a reason to put a type
        # cast, even if it looks redundant to Cython
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        """
        Drop redundant type casts.
        """
        self.visitchildren(node)
        if node.type == node.operand.type:
            return node.operand
        return node

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    def visit_ExprStatNode(self, node):
        """
        Drop useless coercions.
        """
        self.visitchildren(node)
        if isinstance(node.expr, ExprNodes.CoerceToPyTypeNode):
            node.expr = node.expr.arg
        return node

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    def visit_CoerceToBooleanNode(self, node):
        """Drop redundant conversion nodes after tree changes.
        """
        self.visitchildren(node)
        arg = node.arg
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        if isinstance(arg, ExprNodes.PyTypeTestNode):
            arg = arg.arg
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        if isinstance(arg, ExprNodes.CoerceToPyTypeNode):
            if arg.type in (PyrexTypes.py_object_type, Builtin.bool_type):
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                return arg.arg.coerce_to_boolean(self.current_env())
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        return node

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    def visit_CoerceFromPyTypeNode(self, node):
        """Drop redundant conversion nodes after tree changes.

        Also, optimise away calls to Python's builtin int() and
        float() if the result is going to be coerced back into a C
        type anyway.
        """
        self.visitchildren(node)
        arg = node.arg
        if not arg.type.is_pyobject:
            # no Python conversion left at all, just do a C coercion instead
            if node.type == arg.type:
                return arg
            else:
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                return arg.coerce_to(node.type, self.current_env())
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        if isinstance(arg, ExprNodes.PyTypeTestNode):
            arg = arg.arg
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        if arg.is_literal:
            if (node.type.is_int and isinstance(arg, ExprNodes.IntNode) or
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                    node.type.is_float and isinstance(arg, ExprNodes.FloatNode) or
                    node.type.is_int and isinstance(arg, ExprNodes.BoolNode)):
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                return arg.coerce_to(node.type, self.current_env())
        elif isinstance(arg, ExprNodes.CoerceToPyTypeNode):
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            if arg.type is PyrexTypes.py_object_type:
                if node.type.assignable_from(arg.arg.type):
                    # completely redundant C->Py->C coercion
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                    return arg.arg.coerce_to(node.type, self.current_env())
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        elif isinstance(arg, ExprNodes.SimpleCallNode):
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            if node.type.is_int or node.type.is_float:
                return self._optimise_numeric_cast_call(node, arg)
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        elif isinstance(arg, ExprNodes.IndexNode) and not arg.is_buffer_access:
            index_node = arg.index
            if isinstance(index_node, ExprNodes.CoerceToPyTypeNode):
                index_node = index_node.arg
            if index_node.type.is_int:
                return self._optimise_int_indexing(node, arg, index_node)
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        return node

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    PyBytes_GetItemInt_func_type = PyrexTypes.CFuncType(
        PyrexTypes.c_char_type, [
            PyrexTypes.CFuncTypeArg("bytes", Builtin.bytes_type, None),
            PyrexTypes.CFuncTypeArg("index", PyrexTypes.c_py_ssize_t_type, None),
            PyrexTypes.CFuncTypeArg("check_bounds", PyrexTypes.c_int_type, None),
            ],
        exception_value = "((char)-1)",
        exception_check = True)

    def _optimise_int_indexing(self, coerce_node, arg, index_node):
        env = self.current_env()
        bound_check_bool = env.directives['boundscheck'] and 1 or 0
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        if arg.base.type is Builtin.bytes_type:
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            if coerce_node.type in (PyrexTypes.c_char_type, PyrexTypes.c_uchar_type):
                # bytes[index] -> char
                bound_check_node = ExprNodes.IntNode(
                    coerce_node.pos, value=str(bound_check_bool),
                    constant_result=bound_check_bool)
                node = ExprNodes.PythonCapiCallNode(
                    coerce_node.pos, "__Pyx_PyBytes_GetItemInt",
                    self.PyBytes_GetItemInt_func_type,
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                    args=[
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                        arg.base.as_none_safe_node("'NoneType' object is not subscriptable"),
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                        index_node.coerce_to(PyrexTypes.c_py_ssize_t_type, env),
                        bound_check_node,
                        ],
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                    is_temp=True,
                    utility_code=UtilityCode.load_cached(
                        'bytes_index', 'StringTools.c'))
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                if coerce_node.type is not PyrexTypes.c_char_type:
                    node = node.coerce_to(coerce_node.type, env)
                return node
        return coerce_node

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    def _optimise_numeric_cast_call(self, node, arg):
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        function = arg.function
        if not isinstance(function, ExprNodes.NameNode) \
               or not function.type.is_builtin_type \
               or not isinstance(arg.arg_tuple, ExprNodes.TupleNode):
            return node
        args = arg.arg_tuple.args
        if len(args) != 1:
            return node
        func_arg = args[0]
        if isinstance(func_arg, ExprNodes.CoerceToPyTypeNode):
            func_arg = func_arg.arg
        elif func_arg.type.is_pyobject:
            # play safe: Python conversion might work on all sorts of things
            return node
        if function.name == 'int':
            if func_arg.type.is_int or node.type.is_int:
                if func_arg.type == node.type:
                    return func_arg
                elif node.type.assignable_from(func_arg.type) or func_arg.type.is_float:
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                    return ExprNodes.TypecastNode(
                        node.pos, operand=func_arg, type=node.type)
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        elif function.name == 'float':
            if func_arg.type.is_float or node.type.is_float:
                if func_arg.type == node.type:
                    return func_arg
                elif node.type.assignable_from(func_arg.type) or func_arg.type.is_float:
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                    return ExprNodes.TypecastNode(
                        node.pos, operand=func_arg, type=node.type)
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        return node

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    def _error_wrong_arg_count(self, function_name, node, args, expected=None):
        if not expected: # None or 0
            arg_str = ''
        elif isinstance(expected, basestring) or expected > 1:
            arg_str = '...'
        elif expected == 1:
            arg_str = 'x'
        else:
            arg_str = ''
        if expected is not None:
            expected_str = 'expected %s, ' % expected
        else:
            expected_str = ''
        error(node.pos, "%s(%s) called with wrong number of args, %sfound %d" % (
            function_name, arg_str, expected_str, len(args)))

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    ### generic fallbacks

    def _handle_function(self, node, function_name, function, arg_list, kwargs):
        return node

    def _handle_method(self, node, type_name, attr_name, function,
                       arg_list, is_unbound_method, kwargs):
        """
        Try to inject C-API calls for unbound method calls to builtin types.
        While the method declarations in Builtin.py already handle this, we
        can additionally resolve bound and unbound methods here that were
        assigned to variables ahead of time.
        """
        if kwargs:
            return node
        if not function or not function.is_attribute or not function.obj.is_name:
            # cannot track unbound method calls over more than one indirection as
            # the names might have been reassigned in the meantime
            return node
        type_entry = self.current_env().lookup(type_name)
        if not type_entry:
            return node
        method = ExprNodes.AttributeNode(
            node.function.pos,
            obj=ExprNodes.NameNode(
                function.pos,
                name=type_name,
                entry=type_entry,
                type=type_entry.type),
            attribute=attr_name,
            is_called=True).analyse_as_unbound_cmethod_node(self.current_env())
        if method is None:
            return node
        args = node.args
        if args is None and node.arg_tuple:
            args = node.arg_tuple.args
        call_node = ExprNodes.SimpleCallNode(
            node.pos,
            function=method,
            args=args)
        if not is_unbound_method:
            call_node.self = function.obj
        call_node.analyse_c_function_call(self.current_env())
        call_node.analysed = True
        return call_node.coerce_to(node.type, self.current_env())

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    ### builtin types

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    PyDict_Copy_func_type = PyrexTypes.CFuncType(
        Builtin.dict_type, [
            PyrexTypes.CFuncTypeArg("dict", Builtin.dict_type, None)
            ])

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    def _handle_simple_function_dict(self, node, function, pos_args):
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        """Replace dict(some_dict) by PyDict_Copy(some_dict).
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        """
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        if len(pos_args) != 1:
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            return node
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        arg = pos_args[0]
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        if arg.type is Builtin.dict_type:
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            arg = arg.as_none_safe_node("'NoneType' is not iterable")
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            return ExprNodes.PythonCapiCallNode(
                node.pos, "PyDict_Copy", self.PyDict_Copy_func_type,
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                args = [arg],
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                is_temp = node.is_temp
                )
        return node
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    PyList_AsTuple_func_type = PyrexTypes.CFuncType(
        Builtin.tuple_type, [
            PyrexTypes.CFuncTypeArg("list", Builtin.list_type, None)
            ])

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    def _handle_simple_function_tuple(self, node, function, pos_args):
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        """Replace tuple([...]) by a call to PyList_AsTuple.
        """
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        if len(pos_args) != 1:
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            return node
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        arg = pos_args[0]
        if arg.type is Builtin.tuple_type and not arg.may_be_none():
            return arg
        if arg.type is not Builtin.list_type:
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            return node
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        pos_args[0] = arg.as_none_safe_node(
            "'NoneType' object is not iterable")
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        return ExprNodes.PythonCapiCallNode(
            node.pos, "PyList_AsTuple", self.PyList_AsTuple_func_type,
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            args = pos_args,
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            is_temp = node.is_temp
            )

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    PySet_New_func_type = PyrexTypes.CFuncType(
        Builtin.set_type, [
            PyrexTypes.CFuncTypeArg("it", PyrexTypes.py_object_type, None)
        ])

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    def _handle_simple_function_set(self, node, function, pos_args):
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        if len(pos_args) != 1:
            return node
        if pos_args[0].is_sequence_constructor:
            # We can optimise set([x,y,z]) safely into a set literal,
            # but only if we create all items before adding them -
            # adding an item may raise an exception if it is not
            # hashable, but creating the later items may have
            # side-effects.
            args = []
            temps = []
            for arg in pos_args[0].args:
                if not arg.is_simple():
                    arg = UtilNodes.LetRefNode(arg)
                    temps.append(arg)
                args.append(arg)
            result = ExprNodes.SetNode(node.pos, is_temp=1, args=args)
            for temp in temps[::-1]:
                result = UtilNodes.EvalWithTempExprNode(temp, result)
            return result
        else:
            # PySet_New(it) is better than a generic Python call to set(it)
            return ExprNodes.PythonCapiCallNode(
                node.pos, "PySet_New",
                self.PySet_New_func_type,
                args=pos_args,
                is_temp=node.is_temp,
                py_name="set")

    PyFrozenSet_New_func_type = PyrexTypes.CFuncType(
        Builtin.frozenset_type, [
            PyrexTypes.CFuncTypeArg("it", PyrexTypes.py_object_type, None)
        ])

    def _handle_simple_function_frozenset(self, node, function, pos_args):
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        if not pos_args:
            pos_args = [ExprNodes.NullNode(node.pos)]
        elif len(pos_args) > 1:
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            return node
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        elif pos_args[0].type is Builtin.frozenset_type and not pos_args[0].may_be_none():
            return pos_args[0]
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        # PyFrozenSet_New(it) is better than a generic Python call to frozenset(it)
        return ExprNodes.PythonCapiCallNode(
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            node.pos, "__Pyx_PyFrozenSet_New",
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            self.PyFrozenSet_New_func_type,
            args=pos_args,
            is_temp=node.is_temp,
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            utility_code=UtilityCode.load_cached('pyfrozenset_new', 'Builtins.c'),
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            py_name="frozenset")

    PyObject_AsDouble_func_type = PyrexTypes.CFuncType(
        PyrexTypes.c_double_type, [
            PyrexTypes.CFuncTypeArg("obj", PyrexTypes.py_object_type, None),
            ],
        exception_value = "((double)-1)",
        exception_check = True)
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    def _handle_simple_function_float(self, node, function, pos_args):
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        """Transform float() into either a C type cast or a faster C
        function call.
        """
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        # Note: this requires the float() function to be typed as
        # returning a C 'double'
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        if len(pos_args) == 0:
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            return ExprNodes.FloatNode(
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                node, value="0.0", constant_result=0.0
                ).coerce_to(Builtin.float_type, self.current_env())
        elif len(pos_args) != 1:
            self._error_wrong_arg_count('float', node, pos_args, '0 or 1')
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            return node
        func_arg = pos_args[0]
        if isinstance(func_arg, ExprNodes.CoerceToPyTypeNode):
            func_arg = func_arg.arg
        if func_arg.type is PyrexTypes.c_double_type:
            return func_arg
        elif node.type.assignable_from(func_arg.type) or func_arg.type.is_numeric:
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            return ExprNodes.TypecastNode(
                node.pos, operand=func_arg, type=node.type)
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        return ExprNodes.PythonCapiCallNode(
            node.pos, "__Pyx_PyObject_AsDouble",
            self.PyObject_AsDouble_func_type,
            args = pos_args,
            is_temp = node.is_temp,
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            utility_code = load_c_utility('pyobject_as_double'),
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            py_name = "float")

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    PyNumber_Int_func_type = PyrexTypes.CFuncType(
        PyrexTypes.py_object_type, [
            PyrexTypes.CFuncTypeArg("o", PyrexTypes.py_object_type, None)
            ])

    def _handle_simple_function_int(self, node, function, pos_args):
        """Transform int() into a faster C function call.
        """
        if len(pos_args) == 0:
            return ExprNodes.IntNode(node, value="0", constant_result=0,
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                                     type=PyrexTypes.py_object_type)
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        elif len(pos_args) != 1:
            return node  # int(x, base)
        func_arg = pos_args[0]
        if isinstance(func_arg, ExprNodes.CoerceToPyTypeNode):
            return node  # handled in visit_CoerceFromPyTypeNode()
        if func_arg.type.is_pyobject and node.type.is_pyobject:
            return ExprNodes.PythonCapiCallNode(
                node.pos, "PyNumber_Int", self.PyNumber_Int_func_type,
                args=pos_args, is_temp=True)
        return node

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    def _handle_simple_function_bool(self, node, function, pos_args):
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        """Transform bool(x) into a type coercion to a boolean.
        """
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        if len(pos_args) == 0:
            return ExprNodes.BoolNode(
                node.pos, value=False, constant_result=False
                ).coerce_to(Builtin.bool_type, self.current_env())
        elif len(pos_args) != 1:
            self._error_wrong_arg_count('bool', node, pos_args, '0 or 1')
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            return node
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        else:
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            # => !!<bint>(x)  to make sure it's exactly 0 or 1
            operand = pos_args[0].coerce_to_boolean(self.current_env())
            operand = ExprNodes.NotNode(node.pos, operand = operand)
            operand = ExprNodes.NotNode(node.pos, operand = operand)
            # coerce back to Python object as that's the result we are expecting
            return operand.coerce_to_pyobject(self.current_env())
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    ### builtin functions

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    Pyx_strlen_func_type = PyrexTypes.CFuncType(
        PyrexTypes.c_size_t_type, [
            PyrexTypes.CFuncTypeArg("bytes", PyrexTypes.c_char_ptr_type, None)
            ])

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    Pyx_Py_UNICODE_strlen_func_type = PyrexTypes.CFuncType(
        PyrexTypes.c_size_t_type, [
            PyrexTypes.CFuncTypeArg("unicode", PyrexTypes.c_py_unicode_ptr_type, None)
            ])

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    PyObject_Size_func_type = PyrexTypes.CFuncType(
        PyrexTypes.c_py_ssize_t_type, [
            PyrexTypes.CFuncTypeArg("obj", PyrexTypes.py_object_type, None)
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            ],
        exception_value="-1")
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    _map_to_capi_len_function = {
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        Builtin.unicode_type   : "__Pyx_PyUnicode_GET_LENGTH",
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        Builtin.bytes_type     : "PyBytes_GET_SIZE",
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        Builtin.list_type      : "PyList_GET_SIZE",
        Builtin.tuple_type     : "PyTuple_GET_SIZE",
        Builtin.dict_type      : "PyDict_Size",
        Builtin.set_type       : "PySet_Size",
        Builtin.frozenset_type : "PySet_Size",
        }.get

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    _ext_types_with_pysize = set(["cpython.array.array"])

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    def _handle_simple_function_len(self, node, function, pos_args):
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        """Replace len(char*) by the equivalent call to strlen(),
        len(Py_UNICODE) by the equivalent Py_UNICODE_strlen() and
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        len(known_builtin_type) by an equivalent C-API call.
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        """
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        if len(pos_args) != 1:
            self._error_wrong_arg_count('len', node, pos_args, 1)
            return node
        arg = pos_args[0]
        if isinstance(arg, ExprNodes.CoerceToPyTypeNode):
            arg = arg.arg
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        if arg.type.is_string:
            new_node = ExprNodes.PythonCapiCallNode(
                node.pos, "strlen", self.Pyx_strlen_func_type,
                args = [arg],
                is_temp = node.is_temp,
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                utility_code = UtilityCode.load_cached("IncludeStringH", "StringTools.c"))
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        elif arg.type.is_pyunicode_ptr:
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            new_node = ExprNodes.PythonCapiCallNode(
                node.pos, "__Pyx_Py_UNICODE_strlen", self.Pyx_Py_UNICODE_strlen_func_type,
                args = [arg],
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                is_temp = node.is_temp)
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        elif arg.type.is_pyobject:
            cfunc_name = self._map_to_capi_len_function(arg.type)
            if cfunc_name is None:
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                arg_type = arg.type
                if ((arg_type.is_extension_type or arg_type.is_builtin_type)
                    and arg_type.entry.qualified_name in self._ext_types_with_pysize):
                    cfunc_name = 'Py_SIZE'
                else:
                    return node
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            arg = arg.as_none_safe_node(
                "object of type 'NoneType' has no len()")
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            new_node = ExprNodes.PythonCapiCallNode(
                node.pos, cfunc_name, self.PyObject_Size_func_type,
                args = [arg],
                is_temp = node.is_temp)
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        elif arg.type.is_unicode_char:
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            return ExprNodes.IntNode(node.pos, value='1', constant_result=1,
                                     type=node.type)
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        else:
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            return node
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        if node.type not in (PyrexTypes.c_size_t_type, PyrexTypes.c_py_ssize_t_type):
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            new_node = new_node.coerce_to(node.type, self.current_env())
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        return new_node
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    Pyx_Type_func_type = PyrexTypes.CFuncType(
        Builtin.type_type, [
            PyrexTypes.CFuncTypeArg("object", PyrexTypes.py_object_type, None)
            ])

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    def _handle_simple_function_type(self, node, function, pos_args):
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        """Replace type(o) by a macro call to Py_TYPE(o).
        """
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        if len(pos_args) != 1:
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            return node
        node = ExprNodes.PythonCapiCallNode(
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            node.pos, "Py_TYPE", self.Pyx_Type_func_type,
            args = pos_args,
            is_temp = False)
        return ExprNodes.CastNode(node, PyrexTypes.py_object_type)
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    Py_type_check_func_type = PyrexTypes.CFuncType(
        PyrexTypes.c_bint_type, [
            PyrexTypes.CFuncTypeArg("arg", PyrexTypes.py_object_type, None)
            ])

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    def _handle_simple_function_isinstance(self, node, function, pos_args):
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        """Replace isinstance() checks against builtin types by the
        corresponding C-API call.
        """
        if len(pos_args) != 2:
            return node
        arg, types = pos_args
        temp = None
        if isinstance(types, ExprNodes.TupleNode):
            types = types.args
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            if arg.is_attribute or not arg.is_simple():
                arg = temp = UtilNodes.ResultRefNode(arg)
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        elif types.type is Builtin.type_type:
            types = [types]
        else:
            return node

        tests = []
        test_nodes = []
        env = self.current_env()
        for test_type_node in types:
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            builtin_type = None
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            if test_type_node.is_name:
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                if test_type_node.entry:
                    entry = env.lookup(test_type_node.entry.name)
                    if entry and entry.type and entry.type.is_builtin_type:
                        builtin_type = entry.type
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            if builtin_type is Builtin.type_type:
                # all types have type "type", but there's only one 'type'
                if entry.name != 'type' or not (
                        entry.scope and entry.scope.is_builtin_scope):
                    builtin_type = None
            if builtin_type is not None:
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                type_check_function = entry.type.type_check_function(exact=False)
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                if type_check_function in tests:
                    continue
                tests.append(type_check_function)
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                type_check_args = [arg]
            elif test_type_node.type is Builtin.type_type:
                type_check_function = '__Pyx_TypeCheck'
                type_check_args = [arg, test_type_node]
            else:
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                return node
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            test_nodes.append(
                ExprNodes.PythonCapiCallNode(
                    test_type_node.pos, type_check_function, self.Py_type_check_func_type,
                    args = type_check_args,
                    is_temp = True,
                    ))
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        def join_with_or(a,b, make_binop_node=ExprNodes.binop_node):
            or_node = make_binop_node(node.pos, 'or', a, b)
            or_node.type = PyrexTypes.c_bint_type
            or_node.is_temp = True
            return or_node

        test_node = reduce(join_with_or, test_nodes).coerce_to(node.type, env)
        if temp is not None:
            test_node = UtilNodes.EvalWithTempExprNode(temp, test_node)
        return test_node

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    def _handle_simple_function_ord(self, node, function, pos_args):
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        """Unpack ord(Py_UNICODE) and ord('X').
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        """
        if len(pos_args) != 1:
            return node
        arg = pos_args[0]
        if isinstance(arg, ExprNodes.CoerceToPyTypeNode):
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            if arg.arg.type.is_unicode_char:
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                return ExprNodes.TypecastNode(
                    arg.pos, operand=arg.arg, type=PyrexTypes.c_int_type
                    ).coerce_to(node.type, self.current_env())
        elif isinstance(arg, ExprNodes.UnicodeNode):
            if len(arg.value) == 1:
                return ExprNodes.IntNode(
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                    arg.pos, type=PyrexTypes.c_int_type,
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                    value=str(ord(arg.value)),
                    constant_result=ord(arg.value)
                    ).coerce_to(node.type, self.current_env())
        elif isinstance(arg, ExprNodes.StringNode):
            if arg.unicode_value and len(arg.unicode_value) == 1 \
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                    and ord(arg.unicode_value) <= 255:  # Py2/3 portability
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                return ExprNodes.IntNode(
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                    arg.pos, type=PyrexTypes.c_int_type,
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                    value=str(ord(arg.unicode_value)),
                    constant_result=ord(arg.unicode_value)
                    ).coerce_to(node.type, self.current_env())
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        return node

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    ### special methods

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    Pyx_tp_new_func_type = PyrexTypes.CFuncType(
        PyrexTypes.py_object_type, [
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            PyrexTypes.CFuncTypeArg("type",   PyrexTypes.py_object_type, None),
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            PyrexTypes.CFuncTypeArg("args",   Builtin.tuple_type, None),
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            ])

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    Pyx_tp_new_kwargs_func_type = PyrexTypes.CFuncType(
        PyrexTypes.py_object_type, [
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            PyrexTypes.CFuncTypeArg("type",   PyrexTypes.py_object_type, None),
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            PyrexTypes.CFuncTypeArg("args",   Builtin.tuple_type, None),
            PyrexTypes.CFuncTypeArg("kwargs", Builtin.dict_type, None),
        ])

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    def _handle_any_slot__new__(self, node, function, args,
                                is_unbound_method, kwargs=None):
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        """Replace 'exttype.__new__(exttype, ...)' by a call to exttype->tp_new()
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        """
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        obj = function.obj
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        if not is_unbound_method or len(args) < 1:
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            return node
        type_arg = args[0]
        if not obj.is_name or not type_arg.is_name:
            # play safe
            return node
        if obj.type != Builtin.type_type or type_arg.type != Builtin.type_type:
            # not a known type, play safe
            return node
        if not type_arg.type_entry or not obj.type_entry:
            if obj.name != type_arg.name:
                return node
            # otherwise, we know it's a type and we know it's the same
            # type for both - that should do
        elif type_arg.type_entry != obj.type_entry:
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            # different types - may or may not lead to an error at runtime
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            return node

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        args_tuple = ExprNodes.TupleNode(node.pos, args=args[1:])
        args_tuple = args_tuple.analyse_types(
            self.current_env(), skip_children=True)
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        if type_arg.type_entry:
            ext_type = type_arg.type_entry.type
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            if (ext_type.is_extension_type and ext_type.typeobj_cname and
                    ext_type.scope.global_scope() == self.current_env().global_scope()):
                # known type in current module
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                tp_slot = TypeSlots.ConstructorSlot("tp_new", '__new__')
                slot_func_cname = TypeSlots.get_slot_function(ext_type.scope, tp_slot)
                if slot_func_cname:
                    cython_scope = self.context.cython_scope
                    PyTypeObjectPtr = PyrexTypes.CPtrType(
                        cython_scope.lookup('PyTypeObject').type)
                    pyx_tp_new_kwargs_func_type = PyrexTypes.CFuncType(
                        PyrexTypes.py_object_type, [
                            PyrexTypes.CFuncTypeArg("type",   PyTypeObjectPtr, None),
                            PyrexTypes.CFuncTypeArg("args",   PyrexTypes.py_object_type, None),
                            PyrexTypes.CFuncTypeArg("kwargs", PyrexTypes.py_object_type, None),
                            ])

                    type_arg = ExprNodes.CastNode(type_arg, PyTypeObjectPtr)
                    if not kwargs:
                        kwargs = ExprNodes.NullNode(node.pos, type=PyrexTypes.py_object_type)  # hack?
                    return ExprNodes.PythonCapiCallNode(
                        node.pos, slot_func_cname,
                        pyx_tp_new_kwargs_func_type,
                        args=[type_arg, args_tuple, kwargs],
                        is_temp=True)
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        else:
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            # arbitrary variable, needs a None check for safety
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            type_arg = type_arg.as_none_safe_node(
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                "object.__new__(X): X is not a type object (NoneType)")

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        utility_code = UtilityCode.load_cached('tp_new', 'ObjectHandling.c')
        if kwargs:
            return ExprNodes.PythonCapiCallNode(
                node.pos, "__Pyx_tp_new_kwargs", self.Pyx_tp_new_kwargs_func_type,
                args=[type_arg, args_tuple, kwargs],
                utility_code=utility_code,
                is_temp=node.is_temp
                )
        else:
            return ExprNodes.PythonCapiCallNode(
                node.pos, "__Pyx_tp_new", self.Pyx_tp_new_func_type,
                args=[type_arg, args_tuple],
                utility_code=utility_code,
                is_temp=node.is_temp
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            )

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    ### methods of builtin types

    PyObject_Append_func_type = PyrexTypes.CFuncType(
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        PyrexTypes.c_returncode_type, [
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            PyrexTypes.CFuncTypeArg("list", PyrexTypes.py_object_type, None),
            PyrexTypes.CFuncTypeArg("item", PyrexTypes.py_object_type, None),
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            ],
        exception_value="-1")
2455

2456
    def _handle_simple_method_object_append(self, node, function, args, is_unbound_method):
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        """Optimistic optimisation as X.append() is almost always
        referring to a list.
        """
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        if len(args) != 2 or node.result_is_used:
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            return node

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        return ExprNodes.PythonCapiCallNode(
            node.pos, "__Pyx_PyObject_Append", self.PyObject_Append_func_type,
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            args=args,
            may_return_none=False,
            is_temp=node.is_temp,
            result_is_used=False,
            utility_code=load_c_utility('append')
        )
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    PyByteArray_Append_func_type = PyrexTypes.CFuncType(
        PyrexTypes.c_returncode_type, [
            PyrexTypes.CFuncTypeArg("bytearray", PyrexTypes.py_object_type, None),
            PyrexTypes.CFuncTypeArg("value", PyrexTypes.c_int_type, None),
            ],
        exception_value="-1")

    PyByteArray_AppendObject_func_type = PyrexTypes.CFuncType(
        PyrexTypes.c_returncode_type, [
            PyrexTypes.CFuncTypeArg("bytearray", PyrexTypes.py_object_type, None),
            PyrexTypes.CFuncTypeArg("value", PyrexTypes.py_object_type, None),
            ],
        exception_value="-1")

    def _handle_simple_method_bytearray_append(self, node, function, args, is_unbound_method):
        if len(args) != 2:
            return node
        func_name = "__Pyx_PyByteArray_Append"
        func_type = self.PyByteArray_Append_func_type

        value = unwrap_coerced_node(args[1])
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        if value.type.is_int or isinstance(value, ExprNodes.IntNode):
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            value = value.coerce_to(PyrexTypes.c_int_type, self.current_env())
            utility_code = UtilityCode.load_cached("ByteArrayAppend", "StringTools.c")
        elif value.is_string_literal:
            if not value.can_coerce_to_char_literal():
                return node
            value = value.coerce_to(PyrexTypes.c_char_type, self.current_env())
            utility_code = UtilityCode.load_cached("ByteArrayAppend", "StringTools.c")
        elif value.type.is_pyobject:
            func_name = "__Pyx_PyByteArray_AppendObject"
            func_type = self.PyByteArray_AppendObject_func_type
            utility_code = UtilityCode.load_cached("ByteArrayAppendObject", "StringTools.c")
        else:
            return node

        new_node = ExprNodes.PythonCapiCallNode(
            node.pos, func_name, func_type,
            args=[args[0], value],
            may_return_none=False,
            is_temp=node.is_temp,
            utility_code=utility_code,
        )
        if node.result_is_used:
            new_node = new_node.coerce_to(node.type, self.current_env())
        return new_node

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    PyObject_Pop_func_type = PyrexTypes.CFuncType(
        PyrexTypes.py_object_type, [
            PyrexTypes.CFuncTypeArg("list", PyrexTypes.py_object_type, None),
            ])

    PyObject_PopIndex_func_type = PyrexTypes.CFuncType(
        PyrexTypes.py_object_type, [
            PyrexTypes.CFuncTypeArg("list", PyrexTypes.py_object_type, None),
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            PyrexTypes.CFuncTypeArg("index", PyrexTypes.c_py_ssize_t_type, None),
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            PyrexTypes.CFuncTypeArg("is_signed", PyrexTypes.c_int_type, None),
        ],
        has_varargs=True)  # to fake the additional macro args that lack a proper C type
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    def _handle_simple_method_list_pop(self, node, function, args, is_unbound_method):
        return self._handle_simple_method_object_pop(
            node, function, args, is_unbound_method, is_list=True)

    def _handle_simple_method_object_pop(self, node, function, args, is_unbound_method, is_list=False):
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        """Optimistic optimisation as X.pop([n]) is almost always
        referring to a list.
        """
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        if not args:
            return node
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        obj = args[0]
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        if is_list:
            type_name = 'List'
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            obj = obj.as_none_safe_node(
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                "'NoneType' object has no attribute '%s'",
                error="PyExc_AttributeError",
                format_args=['pop'])
        else:
            type_name = 'Object'
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        if len(args) == 1:
            return ExprNodes.PythonCapiCallNode(
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                node.pos, "__Pyx_Py%s_Pop" % type_name,
                self.PyObject_Pop_func_type,
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                args=[obj],
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                may_return_none=True,
                is_temp=node.is_temp,
                utility_code=load_c_utility('pop'),
            )
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        elif len(args) == 2:
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            index = unwrap_coerced_node(args[1])
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            orig_index_type = index.type
            if not index.type.is_int:
                if is_list or isinstance(index, ExprNodes.IntNode):
                    index = index.coerce_to(PyrexTypes.c_py_ssize_t_type, self.current_env())
                else:
                    return node
            elif not PyrexTypes.numeric_type_fits(index.type, PyrexTypes.c_py_ssize_t_type):
                return node
            # real type might still be larger at runtime
            if not orig_index_type.is_int:
                orig_index_type = index.type
            if not orig_index_type.create_to_py_utility_code(self.current_env()):
                return node
            convert_func = orig_index_type.to_py_function
            conversion_type = PyrexTypes.CFuncType(
                PyrexTypes.py_object_type, [PyrexTypes.CFuncTypeArg("intval", orig_index_type, None)])
            return ExprNodes.PythonCapiCallNode(
                node.pos, "__Pyx_Py%s_PopIndex" % type_name,
                self.PyObject_PopIndex_func_type,
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                args=[obj, index,
                      ExprNodes.IntNode(index.pos, value=str(orig_index_type.signed and 1 or 0),
                                        constant_result=orig_index_type.signed and 1 or 0,
                                        type=PyrexTypes.c_int_type),
                      ExprNodes.RawCNameExprNode(index.pos, PyrexTypes.c_void_type,
                                                 orig_index_type.declaration_code("")),
                      ExprNodes.RawCNameExprNode(index.pos, conversion_type, convert_func)],
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                may_return_none=True,
                is_temp=node.is_temp,
                utility_code=load_c_utility("pop_index"),
            )
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        return node

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    single_param_func_type = PyrexTypes.CFuncType(
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        PyrexTypes.c_returncode_type, [
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            PyrexTypes.CFuncTypeArg("obj", PyrexTypes.py_object_type, None),
            ],
        exception_value = "-1")
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2601
    def _handle_simple_method_list_sort(self, node, function, args, is_unbound_method):
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        """Call PyList_Sort() instead of the 0-argument l.sort().
        """
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        if len(args) != 1:
2605
            return node
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        return self._substitute_method_call(
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            node, function, "PyList_Sort", self.single_param_func_type,
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            'sort', is_unbound_method, args).coerce_to(node.type, self.current_env)
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    Pyx_PyDict_GetItem_func_type = PyrexTypes.CFuncType(
        PyrexTypes.py_object_type, [
            PyrexTypes.CFuncTypeArg("dict", PyrexTypes.py_object_type, None),
            PyrexTypes.CFuncTypeArg("key", PyrexTypes.py_object_type, None),
            PyrexTypes.CFuncTypeArg("default", PyrexTypes.py_object_type, None),
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            ])
2616

2617
    def _handle_simple_method_dict_get(self, node, function, args, is_unbound_method):
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        """Replace dict.get() by a call to PyDict_GetItem().
        """
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        if len(args) == 2:
            args.append(ExprNodes.NoneNode(node.pos))
        elif len(args) != 3:
            self._error_wrong_arg_count('dict.get', node, args, "2 or 3")
            return node

        return self._substitute_method_call(
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            node, function,
            "__Pyx_PyDict_GetItemDefault", self.Pyx_PyDict_GetItem_func_type,
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            'get', is_unbound_method, args,
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            may_return_none = True,
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            utility_code = load_c_utility("dict_getitem_default"))
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    Pyx_PyDict_SetDefault_func_type = PyrexTypes.CFuncType(
        PyrexTypes.py_object_type, [
            PyrexTypes.CFuncTypeArg("dict", PyrexTypes.py_object_type, None),
            PyrexTypes.CFuncTypeArg("key", PyrexTypes.py_object_type, None),
            PyrexTypes.CFuncTypeArg("default", PyrexTypes.py_object_type, None),
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            PyrexTypes.CFuncTypeArg("is_safe_type", PyrexTypes.c_int_type, None),
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            ])

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    def _handle_simple_method_dict_setdefault(self, node, function, args, is_unbound_method):
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        """Replace dict.setdefault() by calls to PyDict_GetItem() and PyDict_SetItem().
        """
        if len(args) == 2:
            args.append(ExprNodes.NoneNode(node.pos))
        elif len(args) != 3:
            self._error_wrong_arg_count('dict.setdefault', node, args, "2 or 3")
            return node
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        key_type = args[1].type
        if key_type.is_builtin_type:
            is_safe_type = int(key_type.name in
                               'str bytes unicode float int long bool')
        elif key_type is PyrexTypes.py_object_type:
            is_safe_type = -1  # don't know
        else:
            is_safe_type = 0   # definitely not
        args.append(ExprNodes.IntNode(
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            node.pos, value=str(is_safe_type), constant_result=is_safe_type))
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        return self._substitute_method_call(
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            node, function,
            "__Pyx_PyDict_SetDefault", self.Pyx_PyDict_SetDefault_func_type,
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            'setdefault', is_unbound_method, args,
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            may_return_none=True,
            utility_code=load_c_utility('dict_setdefault'))
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    ### unicode type methods

2670 2671
    PyUnicode_uchar_predicate_func_type = PyrexTypes.CFuncType(
        PyrexTypes.c_bint_type, [
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            PyrexTypes.CFuncTypeArg("uchar", PyrexTypes.c_py_ucs4_type, None),
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            ])

2675
    def _inject_unicode_predicate(self, node, function, args, is_unbound_method):
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        if is_unbound_method or len(args) != 1:
            return node
        ustring = args[0]
        if not isinstance(ustring, ExprNodes.CoerceToPyTypeNode) or \
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               not ustring.arg.type.is_unicode_char:
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            return node
        uchar = ustring.arg
2683
        method_name = function.attribute
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        if method_name == 'istitle':
            # istitle() doesn't directly map to Py_UNICODE_ISTITLE()
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            utility_code = UtilityCode.load_cached(
                "py_unicode_istitle", "StringTools.c")
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            function_name = '__Pyx_Py_UNICODE_ISTITLE'
        else:
            utility_code = None
            function_name = 'Py_UNICODE_%s' % method_name.upper()
        func_call = self._substitute_method_call(
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            node, function,
            function_name, self.PyUnicode_uchar_predicate_func_type,
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            method_name, is_unbound_method, [uchar],
            utility_code = utility_code)
        if node.type.is_pyobject:
            func_call = func_call.coerce_to_pyobject(self.current_env)
        return func_call

    _handle_simple_method_unicode_isalnum   = _inject_unicode_predicate
    _handle_simple_method_unicode_isalpha   = _inject_unicode_predicate
    _handle_simple_method_unicode_isdecimal = _inject_unicode_predicate
    _handle_simple_method_unicode_isdigit   = _inject_unicode_predicate
    _handle_simple_method_unicode_islower   = _inject_unicode_predicate
    _handle_simple_method_unicode_isnumeric = _inject_unicode_predicate
    _handle_simple_method_unicode_isspace   = _inject_unicode_predicate
    _handle_simple_method_unicode_istitle   = _inject_unicode_predicate
    _handle_simple_method_unicode_isupper   = _inject_unicode_predicate

    PyUnicode_uchar_conversion_func_type = PyrexTypes.CFuncType(
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        PyrexTypes.c_py_ucs4_type, [
            PyrexTypes.CFuncTypeArg("uchar", PyrexTypes.c_py_ucs4_type, None),
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            ])

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    def _inject_unicode_character_conversion(self, node, function, args, is_unbound_method):
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        if is_unbound_method or len(args) != 1:
            return node
        ustring = args[0]
        if not isinstance(ustring, ExprNodes.CoerceToPyTypeNode) or \
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               not ustring.arg.type.is_unicode_char:
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            return node
        uchar = ustring.arg
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        method_name = function.attribute
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        function_name = 'Py_UNICODE_TO%s' % method_name.upper()
        func_call = self._substitute_method_call(
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            node, function,
            function_name, self.PyUnicode_uchar_conversion_func_type,
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            method_name, is_unbound_method, [uchar])
        if node.type.is_pyobject:
            func_call = func_call.coerce_to_pyobject(self.current_env)
        return func_call

    _handle_simple_method_unicode_lower = _inject_unicode_character_conversion
    _handle_simple_method_unicode_upper = _inject_unicode_character_conversion
    _handle_simple_method_unicode_title = _inject_unicode_character_conversion

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    PyUnicode_Splitlines_func_type = PyrexTypes.CFuncType(
        Builtin.list_type, [
            PyrexTypes.CFuncTypeArg("str", Builtin.unicode_type, None),
            PyrexTypes.CFuncTypeArg("keepends", PyrexTypes.c_bint_type, None),
            ])

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    def _handle_simple_method_unicode_splitlines(self, node, function, args, is_unbound_method):
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        """Replace unicode.splitlines(...) by a direct call to the
        corresponding C-API function.
        """
        if len(args) not in (1,2):
            self._error_wrong_arg_count('unicode.splitlines', node, args, "1 or 2")
            return node
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        self._inject_bint_default_argument(node, args, 1, False)
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        return self._substitute_method_call(
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            node, function,
            "PyUnicode_Splitlines", self.PyUnicode_Splitlines_func_type,
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            'splitlines', is_unbound_method, args)

    PyUnicode_Split_func_type = PyrexTypes.CFuncType(
        Builtin.list_type, [
            PyrexTypes.CFuncTypeArg("str", Builtin.unicode_type, None),
            PyrexTypes.CFuncTypeArg("sep", PyrexTypes.py_object_type, None),
            PyrexTypes.CFuncTypeArg("maxsplit", PyrexTypes.c_py_ssize_t_type, None),
            ]
        )

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    def _handle_simple_method_unicode_split(self, node, function, args, is_unbound_method):
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        """Replace unicode.split(...) by a direct call to the
        corresponding C-API function.
        """
        if len(args) not in (1,2,3):
            self._error_wrong_arg_count('unicode.split', node, args, "1-3")
            return node
        if len(args) < 2:
            args.append(ExprNodes.NullNode(node.pos))
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        self._inject_int_default_argument(
            node, args, 2, PyrexTypes.c_py_ssize_t_type, "-1")
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        return self._substitute_method_call(
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            node, function,
            "PyUnicode_Split", self.PyUnicode_Split_func_type,
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            'split', is_unbound_method, args)

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    PyString_Tailmatch_func_type = PyrexTypes.CFuncType(
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        PyrexTypes.c_bint_type, [
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            PyrexTypes.CFuncTypeArg("str", PyrexTypes.py_object_type, None),  # bytes/str/unicode
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            PyrexTypes.CFuncTypeArg("substring", PyrexTypes.py_object_type, None),
            PyrexTypes.CFuncTypeArg("start", PyrexTypes.c_py_ssize_t_type, None),
            PyrexTypes.CFuncTypeArg("end", PyrexTypes.c_py_ssize_t_type, None),
            PyrexTypes.CFuncTypeArg("direction", PyrexTypes.c_int_type, None),
            ],
        exception_value = '-1')

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    def _handle_simple_method_unicode_endswith(self, node, function, args, is_unbound_method):
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        return self._inject_tailmatch(
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            node, function, args, is_unbound_method, 'unicode', 'endswith',
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            unicode_tailmatch_utility_code, +1)
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    def _handle_simple_method_unicode_startswith(self, node, function, args, is_unbound_method):
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        return self._inject_tailmatch(
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            node, function, args, is_unbound_method, 'unicode', 'startswith',
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            unicode_tailmatch_utility_code, -1)
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    def _inject_tailmatch(self, node, function, args, is_unbound_method, type_name,
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                          method_name, utility_code, direction):
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        """Replace unicode.startswith(...) and unicode.endswith(...)
        by a direct call to the corresponding C-API function.
        """
        if len(args) not in (2,3,4):
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            self._error_wrong_arg_count('%s.%s' % (type_name, method_name), node, args, "2-4")
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            return node
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        self._inject_int_default_argument(
            node, args, 2, PyrexTypes.c_py_ssize_t_type, "0")
        self._inject_int_default_argument(
            node, args, 3, PyrexTypes.c_py_ssize_t_type, "PY_SSIZE_T_MAX")
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        args.append(ExprNodes.IntNode(
            node.pos, value=str(direction), type=PyrexTypes.c_int_type))

        method_call = self._substitute_method_call(
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            node, function,
            "__Pyx_Py%s_Tailmatch" % type_name.capitalize(),
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            self.PyString_Tailmatch_func_type,
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            method_name, is_unbound_method, args,
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            utility_code = utility_code)
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        return method_call.coerce_to(Builtin.bool_type, self.current_env())
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    PyUnicode_Find_func_type = PyrexTypes.CFuncType(
        PyrexTypes.c_py_ssize_t_type, [
            PyrexTypes.CFuncTypeArg("str", Builtin.unicode_type, None),
            PyrexTypes.CFuncTypeArg("substring", PyrexTypes.py_object_type, None),
            PyrexTypes.CFuncTypeArg("start", PyrexTypes.c_py_ssize_t_type, None),
            PyrexTypes.CFuncTypeArg("end", PyrexTypes.c_py_ssize_t_type, None),
            PyrexTypes.CFuncTypeArg("direction", PyrexTypes.c_int_type, None),
            ],
        exception_value = '-2')

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    def _handle_simple_method_unicode_find(self, node, function, args, is_unbound_method):
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        return self._inject_unicode_find(
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            node, function, args, is_unbound_method, 'find', +1)
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    def _handle_simple_method_unicode_rfind(self, node, function, args, is_unbound_method):
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        return self._inject_unicode_find(
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            node, function, args, is_unbound_method, 'rfind', -1)
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    def _inject_unicode_find(self, node, function, args, is_unbound_method,
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                             method_name, direction):
        """Replace unicode.find(...) and unicode.rfind(...) by a
        direct call to the corresponding C-API function.
        """
        if len(args) not in (2,3,4):
            self._error_wrong_arg_count('unicode.%s' % method_name, node, args, "2-4")
            return node
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        self._inject_int_default_argument(
            node, args, 2, PyrexTypes.c_py_ssize_t_type, "0")
        self._inject_int_default_argument(
            node, args, 3, PyrexTypes.c_py_ssize_t_type, "PY_SSIZE_T_MAX")
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        args.append(ExprNodes.IntNode(
            node.pos, value=str(direction), type=PyrexTypes.c_int_type))

        method_call = self._substitute_method_call(
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            node, function, "PyUnicode_Find", self.PyUnicode_Find_func_type,
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            method_name, is_unbound_method, args)
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        return method_call.coerce_to_pyobject(self.current_env())
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    PyUnicode_Count_func_type = PyrexTypes.CFuncType(
        PyrexTypes.c_py_ssize_t_type, [
            PyrexTypes.CFuncTypeArg("str", Builtin.unicode_type, None),
            PyrexTypes.CFuncTypeArg("substring", PyrexTypes.py_object_type, None),
            PyrexTypes.CFuncTypeArg("start", PyrexTypes.c_py_ssize_t_type, None),
            PyrexTypes.CFuncTypeArg("end", PyrexTypes.c_py_ssize_t_type, None),
            ],
        exception_value = '-1')

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    def _handle_simple_method_unicode_count(self, node, function, args, is_unbound_method):
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        """Replace unicode.count(...) by a direct call to the
        corresponding C-API function.
        """
        if len(args) not in (2,3,4):
            self._error_wrong_arg_count('unicode.count', node, args, "2-4")
            return node
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        self._inject_int_default_argument(
            node, args, 2, PyrexTypes.c_py_ssize_t_type, "0")
        self._inject_int_default_argument(
            node, args, 3, PyrexTypes.c_py_ssize_t_type, "PY_SSIZE_T_MAX")
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        method_call = self._substitute_method_call(
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            node, function, "PyUnicode_Count", self.PyUnicode_Count_func_type,
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            'count', is_unbound_method, args)
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        return method_call.coerce_to_pyobject(self.current_env())
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    PyUnicode_Replace_func_type = PyrexTypes.CFuncType(
        Builtin.unicode_type, [
            PyrexTypes.CFuncTypeArg("str", Builtin.unicode_type, None),
            PyrexTypes.CFuncTypeArg("substring", PyrexTypes.py_object_type, None),
            PyrexTypes.CFuncTypeArg("replstr", PyrexTypes.py_object_type, None),
            PyrexTypes.CFuncTypeArg("maxcount", PyrexTypes.c_py_ssize_t_type, None),
            ])

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    def _handle_simple_method_unicode_replace(self, node, function, args, is_unbound_method):
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        """Replace unicode.replace(...) by a direct call to the
        corresponding C-API function.
        """
        if len(args) not in (3,4):
            self._error_wrong_arg_count('unicode.replace', node, args, "3-4")
            return node
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        self._inject_int_default_argument(
            node, args, 3, PyrexTypes.c_py_ssize_t_type, "-1")
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        return self._substitute_method_call(
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            node, function, "PyUnicode_Replace", self.PyUnicode_Replace_func_type,
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            'replace', is_unbound_method, args)

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    PyUnicode_AsEncodedString_func_type = PyrexTypes.CFuncType(
        Builtin.bytes_type, [
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            PyrexTypes.CFuncTypeArg("obj", Builtin.unicode_type, None),
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            PyrexTypes.CFuncTypeArg("encoding", PyrexTypes.c_char_ptr_type, None),
            PyrexTypes.CFuncTypeArg("errors", PyrexTypes.c_char_ptr_type, None),
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            ])
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    PyUnicode_AsXyzString_func_type = PyrexTypes.CFuncType(
        Builtin.bytes_type, [
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            PyrexTypes.CFuncTypeArg("obj", Builtin.unicode_type, None),
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            ])
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    _special_encodings = ['UTF8', 'UTF16', 'Latin1', 'ASCII',
                          'unicode_escape', 'raw_unicode_escape']

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    _special_codecs = [ (name, codecs.getencoder(name))
                        for name in _special_encodings ]
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    def _handle_simple_method_unicode_encode(self, node, function, args, is_unbound_method):
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        """Replace unicode.encode(...) by a direct C-API call to the
        corresponding codec.
        """
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        if len(args) < 1 or len(args) > 3:
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            self._error_wrong_arg_count('unicode.encode', node, args, '1-3')
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            return node

        string_node = args[0]

        if len(args) == 1:
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            null_node = ExprNodes.NullNode(node.pos)
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            return self._substitute_method_call(
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                node, function, "PyUnicode_AsEncodedString",
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                self.PyUnicode_AsEncodedString_func_type,
                'encode', is_unbound_method, [string_node, null_node, null_node])

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        parameters = self._unpack_encoding_and_error_mode(node.pos, args)
        if parameters is None:
            return node
        encoding, encoding_node, error_handling, error_handling_node = parameters

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        if encoding and isinstance(string_node, ExprNodes.UnicodeNode):
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            # constant, so try to do the encoding at compile time
            try:
                value = string_node.value.encode(encoding, error_handling)
            except:
                # well, looks like we can't
                pass
            else:
                value = BytesLiteral(value)
                value.encoding = encoding
                return ExprNodes.BytesNode(
                    string_node.pos, value=value, type=Builtin.bytes_type)

2965
        if encoding and error_handling == 'strict':
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            # try to find a specific encoder function
            codec_name = self._find_special_codec_name(encoding)
            if codec_name is not None:
                encode_function = "PyUnicode_As%sString" % codec_name
                return self._substitute_method_call(
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                    node, function, encode_function,
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                    self.PyUnicode_AsXyzString_func_type,
                    'encode', is_unbound_method, [string_node])

        return self._substitute_method_call(
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            node, function, "PyUnicode_AsEncodedString",
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            self.PyUnicode_AsEncodedString_func_type,
            'encode', is_unbound_method,
            [string_node, encoding_node, error_handling_node])

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    PyUnicode_DecodeXyz_func_ptr_type = PyrexTypes.CPtrType(PyrexTypes.CFuncType(
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        Builtin.unicode_type, [
            PyrexTypes.CFuncTypeArg("string", PyrexTypes.c_char_ptr_type, None),
            PyrexTypes.CFuncTypeArg("size", PyrexTypes.c_py_ssize_t_type, None),
            PyrexTypes.CFuncTypeArg("errors", PyrexTypes.c_char_ptr_type, None),
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            ]))
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    _decode_c_string_func_type = PyrexTypes.CFuncType(
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        Builtin.unicode_type, [
            PyrexTypes.CFuncTypeArg("string", PyrexTypes.c_char_ptr_type, None),
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            PyrexTypes.CFuncTypeArg("start", PyrexTypes.c_py_ssize_t_type, None),
            PyrexTypes.CFuncTypeArg("stop", PyrexTypes.c_py_ssize_t_type, None),
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            PyrexTypes.CFuncTypeArg("encoding", PyrexTypes.c_char_ptr_type, None),
            PyrexTypes.CFuncTypeArg("errors", PyrexTypes.c_char_ptr_type, None),
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            PyrexTypes.CFuncTypeArg("decode_func", PyUnicode_DecodeXyz_func_ptr_type, None),
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            ])
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    _decode_bytes_func_type = PyrexTypes.CFuncType(
        Builtin.unicode_type, [
            PyrexTypes.CFuncTypeArg("string", PyrexTypes.py_object_type, None),
            PyrexTypes.CFuncTypeArg("start", PyrexTypes.c_py_ssize_t_type, None),
            PyrexTypes.CFuncTypeArg("stop", PyrexTypes.c_py_ssize_t_type, None),
            PyrexTypes.CFuncTypeArg("encoding", PyrexTypes.c_char_ptr_type, None),
            PyrexTypes.CFuncTypeArg("errors", PyrexTypes.c_char_ptr_type, None),
            PyrexTypes.CFuncTypeArg("decode_func", PyUnicode_DecodeXyz_func_ptr_type, None),
            ])

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    _decode_cpp_string_func_type = None  # lazy init
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    def _handle_simple_method_bytes_decode(self, node, function, args, is_unbound_method):
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        """Replace char*.decode() by a direct C-API call to the
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        corresponding codec, possibly resolving a slice on the char*.
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        """
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        if not (1 <= len(args) <= 3):
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            self._error_wrong_arg_count('bytes.decode', node, args, '1-3')
            return node
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        # normalise input nodes
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        string_node = args[0]
        start = stop = None
        if isinstance(string_node, ExprNodes.SliceIndexNode):
            index_node = string_node
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            string_node = index_node.base
            start, stop = index_node.start, index_node.stop
            if not start or start.constant_result == 0:
                start = None
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        if isinstance(string_node, ExprNodes.CoerceToPyTypeNode):
            string_node = string_node.arg

        string_type = string_node.type
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        if string_type in (Builtin.bytes_type, Builtin.bytearray_type):
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            if is_unbound_method:
                string_node = string_node.as_none_safe_node(
                    "descriptor '%s' requires a '%s' object but received a 'NoneType'",
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                    format_args=['decode', string_type.name])
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            else:
                string_node = string_node.as_none_safe_node(
                    "'NoneType' object has no attribute '%s'",
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                    error="PyExc_AttributeError",
                    format_args=['decode'])
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        elif not string_type.is_string and not string_type.is_cpp_string:
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            # nothing to optimise here
            return node
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        parameters = self._unpack_encoding_and_error_mode(node.pos, args)
        if parameters is None:
            return node
        encoding, encoding_node, error_handling, error_handling_node = parameters

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        if not start:
            start = ExprNodes.IntNode(node.pos, value='0', constant_result=0)
        elif not start.type.is_int:
            start = start.coerce_to(PyrexTypes.c_py_ssize_t_type, self.current_env())
        if stop and not stop.type.is_int:
            stop = stop.coerce_to(PyrexTypes.c_py_ssize_t_type, self.current_env())

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        # try to find a specific encoder function
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        codec_name = None
        if encoding is not None:
            codec_name = self._find_special_codec_name(encoding)
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        if codec_name is not None:
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            decode_function = ExprNodes.RawCNameExprNode(
                node.pos, type=self.PyUnicode_DecodeXyz_func_ptr_type,
                cname="PyUnicode_Decode%s" % codec_name)
            encoding_node = ExprNodes.NullNode(node.pos)
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        else:
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            decode_function = ExprNodes.NullNode(node.pos)

        # build the helper function call
        temps = []
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        if string_type.is_string:
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            # C string
            if not stop:
                # use strlen() to find the string length, just as CPython would
                if not string_node.is_name:
                    string_node = UtilNodes.LetRefNode(string_node) # used twice
                    temps.append(string_node)
                stop = ExprNodes.PythonCapiCallNode(
                    string_node.pos, "strlen", self.Pyx_strlen_func_type,
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                    args=[string_node],
                    is_temp=False,
                    utility_code=UtilityCode.load_cached("IncludeStringH", "StringTools.c"),
                ).coerce_to(PyrexTypes.c_py_ssize_t_type, self.current_env())
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            helper_func_type = self._decode_c_string_func_type
            utility_code_name = 'decode_c_string'
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        elif string_type.is_cpp_string:
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            # C++ std::string
            if not stop:
                stop = ExprNodes.IntNode(node.pos, value='PY_SSIZE_T_MAX',
                                         constant_result=ExprNodes.not_a_constant)
            if self._decode_cpp_string_func_type is None:
                # lazy init to reuse the C++ string type
                self._decode_cpp_string_func_type = PyrexTypes.CFuncType(
                    Builtin.unicode_type, [
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                        PyrexTypes.CFuncTypeArg("string", string_type, None),
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                        PyrexTypes.CFuncTypeArg("start", PyrexTypes.c_py_ssize_t_type, None),
                        PyrexTypes.CFuncTypeArg("stop", PyrexTypes.c_py_ssize_t_type, None),
                        PyrexTypes.CFuncTypeArg("encoding", PyrexTypes.c_char_ptr_type, None),
                        PyrexTypes.CFuncTypeArg("errors", PyrexTypes.c_char_ptr_type, None),
                        PyrexTypes.CFuncTypeArg("decode_func", self.PyUnicode_DecodeXyz_func_ptr_type, None),
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                    ])
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            helper_func_type = self._decode_cpp_string_func_type
            utility_code_name = 'decode_cpp_string'
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        else:
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            # Python bytes/bytearray object
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            if not stop:
                stop = ExprNodes.IntNode(node.pos, value='PY_SSIZE_T_MAX',
                                         constant_result=ExprNodes.not_a_constant)
            helper_func_type = self._decode_bytes_func_type
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            if string_type is Builtin.bytes_type:
                utility_code_name = 'decode_bytes'
            else:
                utility_code_name = 'decode_bytearray'
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        node = ExprNodes.PythonCapiCallNode(
            node.pos, '__Pyx_%s' % utility_code_name, helper_func_type,
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            args=[string_node, start, stop, encoding_node, error_handling_node, decode_function],
            is_temp=node.is_temp,
3119
            utility_code=UtilityCode.load_cached(utility_code_name, 'StringTools.c'),
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        )
3121

3122 3123 3124
        for temp in temps[::-1]:
            node = UtilNodes.EvalWithTempExprNode(temp, node)
        return node
3125

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    _handle_simple_method_bytearray_decode = _handle_simple_method_bytes_decode

3128 3129 3130
    def _find_special_codec_name(self, encoding):
        try:
            requested_codec = codecs.getencoder(encoding)
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3131
        except LookupError:
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            return None
        for name, codec in self._special_codecs:
            if codec == requested_codec:
                if '_' in name:
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                    name = ''.join([s.capitalize()
                                    for s in name.split('_')])
3138 3139 3140 3141
                return name
        return None

    def _unpack_encoding_and_error_mode(self, pos, args):
3142 3143 3144
        null_node = ExprNodes.NullNode(pos)

        if len(args) >= 2:
3145 3146
            encoding, encoding_node = self._unpack_string_and_cstring_node(args[1])
            if encoding_node is None:
3147
                return None
3148
        else:
3149 3150
            encoding = None
            encoding_node = null_node
3151 3152

        if len(args) == 3:
3153 3154
            error_handling, error_handling_node = self._unpack_string_and_cstring_node(args[2])
            if error_handling_node is None:
3155
                return None
3156 3157
            if error_handling == 'strict':
                error_handling_node = null_node
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        else:
            error_handling = 'strict'
            error_handling_node = null_node

3162
        return (encoding, encoding_node, error_handling, error_handling_node)
3163

3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181
    def _unpack_string_and_cstring_node(self, node):
        if isinstance(node, ExprNodes.CoerceToPyTypeNode):
            node = node.arg
        if isinstance(node, ExprNodes.UnicodeNode):
            encoding = node.value
            node = ExprNodes.BytesNode(
                node.pos, value=BytesLiteral(encoding.utf8encode()),
                type=PyrexTypes.c_char_ptr_type)
        elif isinstance(node, (ExprNodes.StringNode, ExprNodes.BytesNode)):
            encoding = node.value.decode('ISO-8859-1')
            node = ExprNodes.BytesNode(
                node.pos, value=node.value, type=PyrexTypes.c_char_ptr_type)
        elif node.type is Builtin.bytes_type:
            encoding = None
            node = node.coerce_to(PyrexTypes.c_char_ptr_type, self.current_env())
        elif node.type.is_string:
            encoding = None
        else:
3182
            encoding = node = None
3183 3184
        return encoding, node

3185
    def _handle_simple_method_str_endswith(self, node, function, args, is_unbound_method):
3186
        return self._inject_tailmatch(
3187
            node, function, args, is_unbound_method, 'str', 'endswith',
3188
            str_tailmatch_utility_code, +1)
3189

3190
    def _handle_simple_method_str_startswith(self, node, function, args, is_unbound_method):
3191
        return self._inject_tailmatch(
3192
            node, function, args, is_unbound_method, 'str', 'startswith',
3193
            str_tailmatch_utility_code, -1)
3194

3195
    def _handle_simple_method_bytes_endswith(self, node, function, args, is_unbound_method):
3196
        return self._inject_tailmatch(
3197
            node, function, args, is_unbound_method, 'bytes', 'endswith',
3198
            bytes_tailmatch_utility_code, +1)
3199

3200
    def _handle_simple_method_bytes_startswith(self, node, function, args, is_unbound_method):
3201
        return self._inject_tailmatch(
3202
            node, function, args, is_unbound_method, 'bytes', 'startswith',
3203
            bytes_tailmatch_utility_code, -1)
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    '''   # disabled for now, enable when we consider it worth it (see StringTools.c)
    def _handle_simple_method_bytearray_endswith(self, node, function, args, is_unbound_method):
        return self._inject_tailmatch(
            node, function, args, is_unbound_method, 'bytearray', 'endswith',
            bytes_tailmatch_utility_code, +1)

    def _handle_simple_method_bytearray_startswith(self, node, function, args, is_unbound_method):
        return self._inject_tailmatch(
            node, function, args, is_unbound_method, 'bytearray', 'startswith',
            bytes_tailmatch_utility_code, -1)
    '''

3217 3218
    ### helpers

3219
    def _substitute_method_call(self, node, function, name, func_type,
3220
                                attr_name, is_unbound_method, args=(),
3221
                                utility_code=None, is_temp=None,
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                                may_return_none=ExprNodes.PythonCapiCallNode.may_return_none):
3223
        args = list(args)
3224
        if args and not args[0].is_literal:
3225 3226
            self_arg = args[0]
            if is_unbound_method:
3227
                self_arg = self_arg.as_none_safe_node(
3228
                    "descriptor '%s' requires a '%s' object but received a 'NoneType'",
3229
                    format_args=[attr_name, function.obj.name])
3230
            else:
3231
                self_arg = self_arg.as_none_safe_node(
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                    "'NoneType' object has no attribute '%s'",
                    error = "PyExc_AttributeError",
                    format_args = [attr_name])
3235
            args[0] = self_arg
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        if is_temp is None:
            is_temp = node.is_temp
3238
        return ExprNodes.PythonCapiCallNode(
3239
            node.pos, name, func_type,
3240
            args = args,
3241
            is_temp = is_temp,
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            utility_code = utility_code,
            may_return_none = may_return_none,
3244
            result_is_used = node.result_is_used,
3245 3246
            )

3247 3248 3249
    def _inject_int_default_argument(self, node, args, arg_index, type, default_value):
        assert len(args) >= arg_index
        if len(args) == arg_index:
3250 3251
            args.append(ExprNodes.IntNode(node.pos, value=str(default_value),
                                          type=type, constant_result=default_value))
3252
        else:
3253
            args[arg_index] = args[arg_index].coerce_to(type, self.current_env())
3254 3255 3256 3257

    def _inject_bint_default_argument(self, node, args, arg_index, default_value):
        assert len(args) >= arg_index
        if len(args) == arg_index:
3258 3259 3260
            default_value = bool(default_value)
            args.append(ExprNodes.BoolNode(node.pos, value=default_value,
                                           constant_result=default_value))
3261
        else:
3262
            args[arg_index] = args[arg_index].coerce_to_boolean(self.current_env())
3263

3264

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unicode_tailmatch_utility_code = UtilityCode.load_cached('unicode_tailmatch', 'StringTools.c')
bytes_tailmatch_utility_code = UtilityCode.load_cached('bytes_tailmatch', 'StringTools.c')
str_tailmatch_utility_code = UtilityCode.load_cached('str_tailmatch', 'StringTools.c')
3268

3269

3270 3271 3272 3273
class ConstantFolding(Visitor.VisitorTransform, SkipDeclarations):
    """Calculate the result of constant expressions to store it in
    ``expr_node.constant_result``, and replace trivial cases by their
    constant result.
3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284

    General rules:

    - We calculate float constants to make them available to the
      compiler, but we do not aggregate them into a single literal
      node to prevent any loss of precision.

    - We recursively calculate constants from non-literal nodes to
      make them available to the compiler, but we only aggregate
      literal nodes at each step.  Non-literal nodes are never merged
      into a single node.
3285
    """
3286

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3287 3288 3289 3290 3291 3292 3293
    def __init__(self, reevaluate=False):
        """
        The reevaluate argument specifies whether constant values that were
        previously computed should be recomputed.
        """
        super(ConstantFolding, self).__init__()
        self.reevaluate = reevaluate
3294

3295
    def _calculate_const(self, node):
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3296
        if (not self.reevaluate and
3297
                node.constant_result is not ExprNodes.constant_value_not_set):
3298 3299 3300 3301 3302 3303 3304 3305
            return

        # make sure we always set the value
        not_a_constant = ExprNodes.not_a_constant
        node.constant_result = not_a_constant

        # check if all children are constant
        children = self.visitchildren(node)
3306
        for child_result in children.values():
3307 3308
            if type(child_result) is list:
                for child in child_result:
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                    if getattr(child, 'constant_result', not_a_constant) is not_a_constant:
3310
                        return
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            elif getattr(child_result, 'constant_result', not_a_constant) is not_a_constant:
3312 3313 3314 3315 3316 3317 3318
                return

        # now try to calculate the real constant value
        try:
            node.calculate_constant_result()
#            if node.constant_result is not ExprNodes.not_a_constant:
#                print node.__class__.__name__, node.constant_result
3319
        except (ValueError, TypeError, KeyError, IndexError, AttributeError, ArithmeticError):
3320 3321 3322 3323 3324 3325 3326
            # ignore all 'normal' errors here => no constant result
            pass
        except Exception:
            # this looks like a real error
            import traceback, sys
            traceback.print_exc(file=sys.stdout)

3327 3328
    NODE_TYPE_ORDER = [ExprNodes.BoolNode, ExprNodes.CharNode,
                       ExprNodes.IntNode, ExprNodes.FloatNode]
3329 3330 3331 3332 3333 3334 3335 3336

    def _widest_node_class(self, *nodes):
        try:
            return self.NODE_TYPE_ORDER[
                max(map(self.NODE_TYPE_ORDER.index, map(type, nodes)))]
        except ValueError:
            return None

3337 3338 3339 3340
    def _bool_node(self, node, value):
        value = bool(value)
        return ExprNodes.BoolNode(node.pos, value=value, constant_result=value)

3341 3342 3343 3344
    def visit_ExprNode(self, node):
        self._calculate_const(node)
        return node

3345
    def visit_UnopNode(self, node):
3346
        self._calculate_const(node)
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3347
        if not node.has_constant_result():
3348
            if node.operator == '!':
3349
                return self._handle_NotNode(node)
3350 3351 3352
            return node
        if not node.operand.is_literal:
            return node
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3353
        if node.operator == '!':
3354
            return self._bool_node(node, node.constant_result)
3355
        elif isinstance(node.operand, ExprNodes.BoolNode):
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3356 3357 3358
            return ExprNodes.IntNode(node.pos, value=str(int(node.constant_result)),
                                     type=PyrexTypes.c_int_type,
                                     constant_result=int(node.constant_result))
3359
        elif node.operator == '+':
3360 3361 3362 3363 3364
            return self._handle_UnaryPlusNode(node)
        elif node.operator == '-':
            return self._handle_UnaryMinusNode(node)
        return node

3365 3366 3367 3368 3369 3370 3371
    _negate_operator = {
        'in': 'not_in',
        'not_in': 'in',
        'is': 'is_not',
        'is_not': 'is'
    }.get

3372
    def _handle_NotNode(self, node):
3373 3374 3375 3376 3377 3378 3379
        operand = node.operand
        if isinstance(operand, ExprNodes.PrimaryCmpNode):
            operator = self._negate_operator(operand.operator)
            if operator:
                node = copy.copy(operand)
                node.operator = operator
                node = self.visit_PrimaryCmpNode(node)
3380 3381
        return node

3382
    def _handle_UnaryMinusNode(self, node):
3383 3384 3385 3386 3387 3388 3389
        def _negate(value):
            if value.startswith('-'):
                value = value[1:]
            else:
                value = '-' + value
            return value

3390
        node_type = node.operand.type
3391 3392
        if isinstance(node.operand, ExprNodes.FloatNode):
            # this is a safe operation
3393
            return ExprNodes.FloatNode(node.pos, value=_negate(node.operand.value),
3394
                                       type=node_type,
3395
                                       constant_result=node.constant_result)
3396
        if node_type.is_int and node_type.signed or \
3397 3398 3399 3400 3401
                isinstance(node.operand, ExprNodes.IntNode) and node_type.is_pyobject:
            return ExprNodes.IntNode(node.pos, value=_negate(node.operand.value),
                                     type=node_type,
                                     longness=node.operand.longness,
                                     constant_result=node.constant_result)
3402 3403
        return node

3404
    def _handle_UnaryPlusNode(self, node):
3405 3406
        if (node.operand.has_constant_result() and
                    node.constant_result == node.operand.constant_result):
3407 3408 3409
            return node.operand
        return node

3410 3411
    def visit_BoolBinopNode(self, node):
        self._calculate_const(node)
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3412
        if not node.operand1.has_constant_result():
3413
            return node
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3414
        if node.operand1.constant_result:
3415 3416 3417 3418
            if node.operator == 'and':
                return node.operand2
            else:
                return node.operand1
3419
        else:
3420 3421 3422 3423
            if node.operator == 'and':
                return node.operand1
            else:
                return node.operand2
3424

3425 3426 3427 3428
    def visit_BinopNode(self, node):
        self._calculate_const(node)
        if node.constant_result is ExprNodes.not_a_constant:
            return node
3429 3430
        if isinstance(node.constant_result, float):
            return node
3431 3432
        operand1, operand2 = node.operand1, node.operand2
        if not operand1.is_literal or not operand2.is_literal:
3433 3434 3435
            return node

        # now inject a new constant node with the calculated value
3436
        try:
3437
            type1, type2 = operand1.type, operand2.type
3438
            if type1 is None or type2 is None:
3439 3440 3441 3442
                return node
        except AttributeError:
            return node

3443
        if type1.is_numeric and type2.is_numeric:
3444
            widest_type = PyrexTypes.widest_numeric_type(type1, type2)
3445 3446
        else:
            widest_type = PyrexTypes.py_object_type
3447

3448
        target_class = self._widest_node_class(operand1, operand2)
3449 3450
        if target_class is None:
            return node
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3451
        elif target_class is ExprNodes.BoolNode and node.operator in '+-//<<%**>>':
3452 3453
            # C arithmetic results in at least an int type
            target_class = ExprNodes.IntNode
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3454
        elif target_class is ExprNodes.CharNode and node.operator in '+-//<<%**>>&|^':
3455 3456 3457 3458
            # C arithmetic results in at least an int type
            target_class = ExprNodes.IntNode

        if target_class is ExprNodes.IntNode:
3459 3460 3461 3462
            unsigned = getattr(operand1, 'unsigned', '') and \
                       getattr(operand2, 'unsigned', '')
            longness = "LL"[:max(len(getattr(operand1, 'longness', '')),
                                 len(getattr(operand2, 'longness', '')))]
3463
            new_node = ExprNodes.IntNode(pos=node.pos,
3464 3465 3466
                                         unsigned=unsigned, longness=longness,
                                         value=str(int(node.constant_result)),
                                         constant_result=int(node.constant_result))
3467 3468 3469 3470
            # IntNode is smart about the type it chooses, so we just
            # make sure we were not smarter this time
            if widest_type.is_pyobject or new_node.type.is_pyobject:
                new_node.type = PyrexTypes.py_object_type
3471
            else:
3472
                new_node.type = PyrexTypes.widest_numeric_type(widest_type, new_node.type)
3473
        else:
3474
            if target_class is ExprNodes.BoolNode:
3475 3476 3477 3478 3479 3480
                node_value = node.constant_result
            else:
                node_value = str(node.constant_result)
            new_node = target_class(pos=node.pos, type = widest_type,
                                    value = node_value,
                                    constant_result = node.constant_result)
3481 3482
        return new_node

3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507
    def visit_AddNode(self, node):
        self._calculate_const(node)
        if node.constant_result is ExprNodes.not_a_constant:
            return node
        if node.operand1.is_string_literal and node.operand2.is_string_literal:
            # some people combine string literals with a '+'
            str1, str2 = node.operand1, node.operand2
            if isinstance(str1, ExprNodes.UnicodeNode) and isinstance(str2, ExprNodes.UnicodeNode):
                bytes_value = None
                if str1.bytes_value is not None and str2.bytes_value is not None:
                    if str1.bytes_value.encoding == str2.bytes_value.encoding:
                        bytes_value = BytesLiteral(str1.bytes_value + str2.bytes_value)
                        bytes_value.encoding = str1.bytes_value.encoding
                string_value = EncodedString(node.constant_result)
                return ExprNodes.UnicodeNode(
                    str1.pos, value=string_value, constant_result=node.constant_result, bytes_value=bytes_value)
            elif isinstance(str1, ExprNodes.BytesNode) and isinstance(str2, ExprNodes.BytesNode):
                if str1.value.encoding == str2.value.encoding:
                    bytes_value = BytesLiteral(node.constant_result)
                    bytes_value.encoding = str1.value.encoding
                    return ExprNodes.BytesNode(str1.pos, value=bytes_value, constant_result=node.constant_result)
            # all other combinations are rather complicated
            # to get right in Py2/3: encodings, unicode escapes, ...
        return self.visit_BinopNode(node)

3508
    def visit_MulNode(self, node):
3509
        self._calculate_const(node)
3510 3511
        if node.operand1.is_sequence_constructor:
            return self._calculate_constant_seq(node, node.operand1, node.operand2)
3512
        if isinstance(node.operand1, ExprNodes.IntNode) and \
3513 3514
                node.operand2.is_sequence_constructor:
            return self._calculate_constant_seq(node, node.operand2, node.operand1)
3515 3516
        return self.visit_BinopNode(node)

3517
    def _calculate_constant_seq(self, node, sequence_node, factor):
3518 3519 3520
        if factor.constant_result != 1 and sequence_node.args:
            if isinstance(factor.constant_result, (int, long)) and factor.constant_result <= 0:
                del sequence_node.args[:]
3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533
                sequence_node.mult_factor = None
            elif sequence_node.mult_factor is not None:
                if (isinstance(factor.constant_result, (int, long)) and
                        isinstance(sequence_node.mult_factor.constant_result, (int, long))):
                    value = sequence_node.mult_factor.constant_result * factor.constant_result
                    sequence_node.mult_factor = ExprNodes.IntNode(
                        sequence_node.mult_factor.pos,
                        value=str(value), constant_result=value)
                else:
                    # don't know if we can combine the factors, so don't
                    return self.visit_BinopNode(node)
            else:
                sequence_node.mult_factor = factor
3534 3535
        return sequence_node

3536
    def visit_PrimaryCmpNode(self, node):
3537
        # calculate constant partial results in the comparison cascade
3538
        self.visitchildren(node, ['operand1'])
3539 3540 3541
        left_node = node.operand1
        cmp_node = node
        while cmp_node is not None:
3542
            self.visitchildren(cmp_node, ['operand2'])
3543 3544 3545 3546 3547 3548 3549 3550 3551 3552
            right_node = cmp_node.operand2
            cmp_node.constant_result = not_a_constant
            if left_node.has_constant_result() and right_node.has_constant_result():
                try:
                    cmp_node.calculate_cascaded_constant_result(left_node.constant_result)
                except (ValueError, TypeError, KeyError, IndexError, AttributeError, ArithmeticError):
                    pass  # ignore all 'normal' errors here => no constant result
            left_node = right_node
            cmp_node = cmp_node.cascade

3553 3554 3555 3556 3557
        if not node.cascade:
            if node.has_constant_result():
                return self._bool_node(node, node.constant_result)
            return node

3558 3559
        # collect partial cascades: [[value, CmpNode...], [value, CmpNode, ...], ...]
        cascades = [[node.operand1]]
3560
        final_false_result = []
3561 3562 3563 3564 3565

        def split_cascades(cmp_node):
            if cmp_node.has_constant_result():
                if not cmp_node.constant_result:
                    # False => short-circuit
3566
                    final_false_result.append(self._bool_node(cmp_node, False))
3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597
                    return
                else:
                    # True => discard and start new cascade
                    cascades.append([cmp_node.operand2])
            else:
                # not constant => append to current cascade
                cascades[-1].append(cmp_node)
            if cmp_node.cascade:
                split_cascades(cmp_node.cascade)

        split_cascades(node)

        cmp_nodes = []
        for cascade in cascades:
            if len(cascade) < 2:
                continue
            cmp_node = cascade[1]
            pcmp_node = ExprNodes.PrimaryCmpNode(
                cmp_node.pos,
                operand1=cascade[0],
                operator=cmp_node.operator,
                operand2=cmp_node.operand2,
                constant_result=not_a_constant)
            cmp_nodes.append(pcmp_node)

            last_cmp_node = pcmp_node
            for cmp_node in cascade[2:]:
                last_cmp_node.cascade = cmp_node
                last_cmp_node = cmp_node
            last_cmp_node.cascade = None

3598
        if final_false_result:
3599
            # last cascade was constant False
3600
            cmp_nodes.append(final_false_result[0])
3601
        elif not cmp_nodes:
3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615
            # only constants, but no False result
            return self._bool_node(node, True)
        node = cmp_nodes[0]
        if len(cmp_nodes) == 1:
            if node.has_constant_result():
                return self._bool_node(node, node.constant_result)
        else:
            for cmp_node in cmp_nodes[1:]:
                node = ExprNodes.BoolBinopNode(
                    node.pos,
                    operand1=node,
                    operator='and',
                    operand2=cmp_node,
                    constant_result=not_a_constant)
3616
        return node
3617

3618 3619
    def visit_CondExprNode(self, node):
        self._calculate_const(node)
3620
        if not node.test.has_constant_result():
3621 3622 3623 3624 3625 3626
            return node
        if node.test.constant_result:
            return node.true_val
        else:
            return node.false_val

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    def visit_IfStatNode(self, node):
        self.visitchildren(node)
        # eliminate dead code based on constant condition results
        if_clauses = []
        for if_clause in node.if_clauses:
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            condition = if_clause.condition
            if condition.has_constant_result():
                if condition.constant_result:
                    # always true => subsequent clauses can safely be dropped
                    node.else_clause = if_clause.body
                    break
                # else: false => drop clause
            else:
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                # unknown result => normal runtime evaluation
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                if_clauses.append(if_clause)
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        if if_clauses:
            node.if_clauses = if_clauses
            return node
        elif node.else_clause:
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            return node.else_clause
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        else:
            return Nodes.StatListNode(node.pos, stats=[])
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    def visit_SliceIndexNode(self, node):
        self._calculate_const(node)
        # normalise start/stop values
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        if node.start is None or node.start.constant_result is None:
            start = node.start = None
        else:
            start = node.start.constant_result
        if node.stop is None or node.stop.constant_result is None:
            stop = node.stop = None
        else:
            stop = node.stop.constant_result
        # cut down sliced constant sequences
        if node.constant_result is not not_a_constant:
            base = node.base
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            if base.is_sequence_constructor and base.mult_factor is None:
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                base.args = base.args[start:stop]
                return base
            elif base.is_string_literal:
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                base = base.as_sliced_node(start, stop)
                if base is not None:
                    return base
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        return node

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    def visit_ComprehensionNode(self, node):
        self.visitchildren(node)
        if isinstance(node.loop, Nodes.StatListNode) and not node.loop.stats:
            # loop was pruned already => transform into literal
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            if node.type is Builtin.list_type:
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                return ExprNodes.ListNode(
                    node.pos, args=[], constant_result=[])
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            elif node.type is Builtin.set_type:
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                return ExprNodes.SetNode(
                    node.pos, args=[], constant_result=set())
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            elif node.type is Builtin.dict_type:
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                return ExprNodes.DictNode(
                    node.pos, key_value_pairs=[], constant_result={})
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        return node

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    def visit_ForInStatNode(self, node):
        self.visitchildren(node)
        sequence = node.iterator.sequence
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        if isinstance(sequence, ExprNodes.SequenceNode):
            if not sequence.args:
                if node.else_clause:
                    return node.else_clause
                else:
                    # don't break list comprehensions
                    return Nodes.StatListNode(node.pos, stats=[])
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            # iterating over a list literal? => tuples are more efficient
            if isinstance(sequence, ExprNodes.ListNode):
                node.iterator.sequence = sequence.as_tuple()
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        return node

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    def visit_WhileStatNode(self, node):
        self.visitchildren(node)
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        if node.condition and node.condition.has_constant_result():
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            if node.condition.constant_result:
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                node.condition = None
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                node.else_clause = None
            else:
                return node.else_clause
        return node

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    def visit_ExprStatNode(self, node):
        self.visitchildren(node)
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        if not isinstance(node.expr, ExprNodes.ExprNode):
            # ParallelRangeTransform does this ...
            return node
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        # drop unused constant expressions
        if node.expr.has_constant_result():
            return None
        return node

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    # in the future, other nodes can have their own handler method here
    # that can replace them with a constant result node
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    visit_Node = Visitor.VisitorTransform.recurse_to_children
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class FinalOptimizePhase(Visitor.CythonTransform):
    """
    This visitor handles several commuting optimizations, and is run
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    just before the C code generation phase.

    The optimizations currently implemented in this class are:
        - eliminate None assignment and refcounting for first assignment.
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        - isinstance -> typecheck for cdef types
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        - eliminate checks for None and/or types that became redundant after tree changes
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    """
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    def visit_SingleAssignmentNode(self, node):
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        """Avoid redundant initialisation of local variables before their
        first assignment.
        """
        self.visitchildren(node)
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        if node.first:
            lhs = node.lhs
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            lhs.lhs_of_first_assignment = True
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        return node
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    def visit_SimpleCallNode(self, node):
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        """Replace generic calls to isinstance(x, type) by a more efficient
        type check.
        """
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        self.visitchildren(node)
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        if node.function.type.is_cfunction and isinstance(node.function, ExprNodes.NameNode):
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            if node.function.name == 'isinstance' and len(node.args) == 2:
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                type_arg = node.args[1]
                if type_arg.type.is_builtin_type and type_arg.type.name == 'type':
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                    cython_scope = self.context.cython_scope
                    node.function.entry = cython_scope.lookup('PyObject_TypeCheck')
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                    node.function.type = node.function.entry.type
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                    PyTypeObjectPtr = PyrexTypes.CPtrType(cython_scope.lookup('PyTypeObject').type)
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                    node.args[1] = ExprNodes.CastNode(node.args[1], PyTypeObjectPtr)
        return node
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    def visit_PyTypeTestNode(self, node):
        """Remove tests for alternatively allowed None values from
        type tests when we know that the argument cannot be None
        anyway.
        """
        self.visitchildren(node)
        if not node.notnone:
            if not node.arg.may_be_none():
                node.notnone = True
        return node
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    def visit_NoneCheckNode(self, node):
        """Remove None checks from expressions that definitely do not
        carry a None value.
        """
        self.visitchildren(node)
        if not node.arg.may_be_none():
            return node.arg
        return node
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class ConsolidateOverflowCheck(Visitor.CythonTransform):
    """
    This class facilitates the sharing of overflow checking among all nodes
    of a nested arithmetic expression.  For example, given the expression
    a*b + c, where a, b, and x are all possibly overflowing ints, the entire
    sequence will be evaluated and the overflow bit checked only at the end.
    """
    overflow_bit_node = None
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    def visit_Node(self, node):
        if self.overflow_bit_node is not None:
            saved = self.overflow_bit_node
            self.overflow_bit_node = None
            self.visitchildren(node)
            self.overflow_bit_node = saved
        else:
            self.visitchildren(node)
        return node
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    def visit_NumBinopNode(self, node):
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        if node.overflow_check and node.overflow_fold:
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            top_level_overflow = self.overflow_bit_node is None
            if top_level_overflow:
                self.overflow_bit_node = node
            else:
                node.overflow_bit_node = self.overflow_bit_node
                node.overflow_check = False
            self.visitchildren(node)
            if top_level_overflow:
                self.overflow_bit_node = None
        else:
            self.visitchildren(node)
        return node