Commit 003f0ad6 authored by Robert Griesemer's avatar Robert Griesemer

- added missing file

R=r
OCL=21384
CL=21384
parent b8635907
// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package TypeChecker
import (
AST "ast";
Universe "universe";
Globals "globals";
Object "object";
Type "type";
)
type State struct {
level int;
top_scope *Globals.Scope;
}
// ----------------------------------------------------------------------------
// Support
func (s *State) Error(pos int, msg string) {
panicln("error:" + msg);
}
// ----------------------------------------------------------------------------
// Scopes
func (s *State) OpenScope() {
s.top_scope = Globals.NewScope(s.top_scope);
}
func (s *State) CloseScope() {
s.top_scope = s.top_scope.parent;
}
func (s *State) Lookup(ident string) *Globals.Object {
for scope := s.top_scope; scope != nil; scope = scope.parent {
obj := scope.Lookup(ident);
if obj != nil {
return obj;
}
}
return nil;
}
func (s *State) DeclareInScope(scope *Globals.Scope, obj *Globals.Object) {
if s.level > 0 {
panic("cannot declare objects in other packages");
}
obj.pnolev = s.level;
if scope.Lookup(obj.ident) != nil {
s.Error(obj.pos, `"` + obj.ident + `" is declared already`);
return; // don't insert it into the scope
}
scope.Insert(obj);
}
func (s *State) Declare(obj *Globals.Object) {
s.DeclareInScope(s.top_scope, obj);
}
// ----------------------------------------------------------------------------
// Common productions
func (s *State) DeclareIdent(kind int) {
obj := Globals.NewObject(0, kind, "");
s.Declare(obj);
}
// ----------------------------------------------------------------------------
func (s *State) CheckProgram(p *AST.Program) {
s.OpenScope();
{ s.OpenScope();
s.CloseScope();
}
s.CloseScope();
}
// ----------------------------------------------------------------------------
export func CheckProgram(p *AST.Program) {
var s State;
s.CheckProgram(p);
}
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