private AST_variable_declaration Parse_variable_declaration()
{
IncrementDepth();
AST_variable_declaration variable_declaration;
AST_identifier name;
AST_type type = null;
AST_expression expression = null;
Match(var_Keyword);
name = Parse_identifier(Colon | Semicolon);
if (!Match(Colon))
{
Error("':' expected.", lastReadToken);
SkipUntilFollow(Semicolon);
}
else
{
type = Parse_type(Assignment | Semicolon);
switch (LookAheadToken().Kind)
{
case Assignment:
Match(Assignment);
expression = Parse_expression(Semicolon);
break;
case Semicolon:
break;
default:
Error("':=' or ';' expected.", LookAheadToken());
SkipUntilFollow(Semicolon);
break;
}
}
variable_declaration = new AST_variable_declaration(name, type, expression);
DecrementDepth();
return(variable_declaration);
}
private AST_type Parse_type(TokenKind followSet)
{
IncrementDepth();
AST_type type;
Token t = GetNextToken();
switch (t.Kind)
{
case int_Keyword:
DebugPrint("type int");
type = new AST_type(int_type);
break;
case string_Keyword:
DebugPrint("type string");
type = new AST_type(string_type);
break;
case bool_Keyword:
DebugPrint("type bool");
type = new AST_type(bool_type);
break;
default:
Error("Type expected.", t);
SkipUntilFollow(followSet);
type = new AST_type(bool_type);
break;
}
DecrementDepth();
type.Row = t.Row;
type.Column = t.Column;
return(type);
}
public virtual void Visit(AST_type type)
{
}
override public void Visit(AST_type type)
{
base.Visit(type);
}
