Merge pull request #227 from jvkersch/fix-int-times-list

List right multiplication, tuple multiplication

src/runtime/list.cpp

@@ -593,6 +593,7 @@ void setupList() {
 
     list_cls->giveAttr("insert", new BoxedFunction(boxRTFunction((void*)listInsert, NONE, 3)));
     list_cls->giveAttr("__mul__", new BoxedFunction(boxRTFunction((void*)listMul, LIST, 2)));
+    list_cls->giveAttr("__rmul__", new BoxedFunction(boxRTFunction((void*)listMul, LIST, 2)));
 
     list_cls->giveAttr("__iadd__", new BoxedFunction(boxRTFunction((void*)listIAdd, UNKNOWN, 2)));
     list_cls->giveAttr("__add__", new BoxedFunction(boxRTFunction((void*)listAdd, UNKNOWN, 2)));

src/runtime/tuple.cpp

@@ -14,6 +14,7 @@
 
 #include "runtime/tuple.h"
 
+#include <algorithm>
 #include <sstream>
 
 #include "core/ast.h"
@@ -127,6 +128,30 @@ Box* tupleAdd(BoxedTuple* self, Box* rhs) {
     return new BoxedTuple(std::move(velts));
 }
 
+Box* tupleMul(BoxedTuple* self, Box* rhs) {
+    if (rhs->cls != int_cls) {
+        raiseExcHelper(TypeError, "can't multiply sequence by non-int of type '%s'", getTypeName(rhs)->c_str());
+    }
+
+    int n = static_cast<BoxedInt*>(rhs)->n;
+    int s = self->elts.size();
+
+    if (n < 0)
+        n = 0;
+
+    if (s == 0 || n == 1) {
+        return self;
+    } else {
+        BoxedTuple::GCVector velts(n * s);
+        auto iter = velts.begin();
+        for (int i = 0; i < n; ++i) {
+            std::copy(self->elts.begin(), self->elts.end(), iter);
+            iter += s;
+        }
+        return new BoxedTuple(std::move(velts));
+    }
+}
+
 Box* tupleLen(BoxedTuple* t) {
     assert(t->cls == tuple_cls);
     return boxInt(t->elts.size());
@@ -389,6 +414,8 @@ void setupTuple() {
     tuple_cls->giveAttr("__repr__", new BoxedFunction(boxRTFunction((void*)tupleRepr, STR, 1)));
     tuple_cls->giveAttr("__str__", tuple_cls->getattr("__repr__"));
     tuple_cls->giveAttr("__add__", new BoxedFunction(boxRTFunction((void*)tupleAdd, BOXED_TUPLE, 2)));
+    tuple_cls->giveAttr("__mul__", new BoxedFunction(boxRTFunction((void*)tupleMul, BOXED_TUPLE, 2)));
+    tuple_cls->giveAttr("__rmul__", new BoxedFunction(boxRTFunction((void*)tupleMul, BOXED_TUPLE, 2)));
 
     tuple_cls->freeze();
 

test/tests/list.py

@@ -71,3 +71,8 @@ while l:
 l = range(5)
 l.extend(range(5))
 print l
+
+# Repeating a list
+x = [0, 1, 2]
+print 2 * x
+print x * 2

test/tests/tuples.py

@@ -177,3 +177,24 @@ print bool((0,))
 print bool((0, 0))
 
 print (65, (1, 2, 3), 65)
+
+# Multiplying a tuple by an integer
+x = (1, 2, 3)
+print x * -1
+print x * 0
+print x * 1
+print x * 5
+print -1 * x
+print 0 * x
+print 1 * x
+print 5 * x
+
+x = ()
+print x * -1
+print x * 0
+print x * 1
+print x * 5
+print -1 * x
+print 0 * x
+print 1 * x
+print 5 * x