public override void Visit(AST_leaf node)
{
switch (node.Tag)
{
case NodeType.Empty:
// no type
break;
case NodeType.Break:
// no type
break;
case NodeType.IntConst:
node.Type = CbType.Int;
break;
case NodeType.StringConst:
node.Type = CbType.String;
break;
case NodeType.Ident:
CbType typ;
string str = node.Sval;
// check for null value
if (str == "null")
{
typ = CbType.Null;
}
else
{
// check symbol table for identifer
SymTabEntry result = localSymbols.Lookup(str);
if (result != null)
{
typ = result.Type;
}
// if identifier not in symbol table, check in Consts, then if not found report error
else if (!(Consts.TryGetValue(str, out typ)))
{
ReportError(node.LineNumber, "Use of undeclared identifier: '{0}'", str);
// add undeclared variable to the symbol table to prevent additional errors
localSymbols.Binding(str, node.LineNumber);
typ = CbType.Error;
}
}
node.Type = typ;
break;
default:
throw new Exception("{0} is not a tag compatible with an AST_leaf node");
}
}
public override void Visit(AST_leaf node)
{
printTag(node);
switch(node.Tag) {
case NodeType.Ident:
case NodeType.StringConst:
f.WriteLine(" \"{0}\"", node.Sval); break;
case NodeType.IntConst:
f.WriteLine(" {0}", node.Ival); break;
default:
f.WriteLine(); break;
}
}
public override void Visit(AST_leaf node)
{
printTag(node);
switch (node.Tag)
{
case NodeType.Ident:
case NodeType.StringConst:
f.WriteLine(" \"{0}\"", node.Sval); break;
case NodeType.IntConst:
f.WriteLine(" {0}", node.Ival); break;
default:
f.WriteLine(); break;
}
}
public override void Visit(AST_leaf node)
{
switch(node.Tag) {
case NodeType.Empty:
// no type
break;
case NodeType.Break:
// no type
break;
case NodeType.IntConst:
node.Type = CbType.Int;
break;
case NodeType.StringConst:
node.Type = CbType.String;
break;
case NodeType.Ident:
CbType typ;
string str = node.Sval;
// check for null value
if (str == "null")
typ = CbType.Null;
else
{
// check symbol table for identifer
SymTabEntry result = localSymbols.Lookup(str);
if (result != null)
typ = result.Type;
// if identifier not in symbol table, check in Consts, then if not found report error
else if (!(Consts.TryGetValue(str, out typ)))
{
ReportError(node.LineNumber, "Use of undeclared identifier: '{0}'", str);
// add undeclared variable to the symbol table to prevent additional errors
localSymbols.Binding(str, node.LineNumber);
typ = CbType.Error;
}
}
node.Type = typ;
break;
default:
throw new Exception("{0} is not a tag compatible with an AST_leaf node");
}
}
public virtual void Visit(AST_leaf n)
{
Console.WriteLine("Internal compiler error! This method should have been overridden");
}
public virtual void Visit(AST_leaf n)
{
Console.WriteLine("Internal compiler error! This method should have been overridden");
}
