private AST_identifier Parse_identifier(TokenKind followSet)
{
IncrementDepth();
AST_identifier identifier;
Token t = GetNextToken();
if (t.Kind == Identifier)
{
identifier = new AST_identifier(t.Lexeme);
identifier.Row = t.Row;
identifier.Column = t.Column;
DebugPrint("identifier: " + t.Lexeme);
}
else
{
Error("Identifier expected, '" + t.ToString() + "' found.", t);
SkipUntilFollow(followSet);
identifier = new AST_identifier("");
}
DecrementDepth();
return(identifier);
}
private AST_read_statement Parse_read_statement()
{
IncrementDepth();
AST_read_statement read_statement;
Match(read_Keyword);
AST_identifier identifier = Parse_identifier(Semicolon);
DebugPrint("read_statement, identifier = " + identifier.Name);
read_statement = new AST_read_statement(identifier);
DecrementDepth();
return(read_statement);
}
override public void Visit(AST_identifier identifier)
{
base.Visit(identifier);
string name = identifier.Name;
if (name.Length > 0)
{
if (variables.ContainsKey(name))
{
identifier.Declaration = variables.GetValueOrDefault(name);
if (identifier.Declaration.Type != null)
{
identifier.DataType = identifier.Declaration.Type.Kind;
}
}
else
{
Error("Variable '" + name + "' has not been declared.", identifier);
}
}
}
public void IncrementVariable(AST_identifier identifier)
{
Variable var = variables.GetValueOrDefault(identifier.Name);
var.Set(var.IntValue + 1);
}
override public void Visit(AST_identifier identifier)
{
this.value = variables.GetValueOrDefault(identifier.Name).Copy();
}
private AST_for_statement Parse_for_statement()
{
IncrementDepth();
DebugPrint("for_statement");
AST_for_statement for_statement = null;
AST_expression from = null;
AST_expression to = null;
AST_statement_list statement_list = null;
Match(for_Keyword);
AST_identifier identifier = Parse_identifier(in_Keyword);
bool skipForDo = false;
bool skipAll = false;
if (!Match(in_Keyword))
{
Error("'in' expected.", lastReadToken);
// Prefer to skip for .. do and still process the statement_list,
// worst case is to skip everything until 'end for'
SkipUntilFollow(do_Keyword | end_Keyword);
if (LookAheadToken().Kind == end_Keyword)
{
Match(end_Keyword);
Match(for_Keyword);
skipAll = true;
}
else
{
Match(do_Keyword);
skipForDo = true;
}
}
if (!skipAll)
{
if (!skipForDo)
{
from = Parse_expression(RangeDots);
if (!Match(RangeDots))
{
SkipUntilFollow(do_Keyword | end_Keyword);
if (LookAheadToken().Kind == end_Keyword)
{
Match(end_Keyword);
Match(for_Keyword);
skipAll = true;
}
else
{
Match(do_Keyword);
skipForDo = true;
}
}
if (!skipAll && !skipForDo)
{
to = Parse_expression(do_Keyword | end_Keyword);
if (!Match(do_Keyword))
{
Error("'do' expected.", lastReadToken);
ReuseToken();
}
}
}
if (!skipAll)
{
statement_list = Parse_statement_list();
if (!Match(end_Keyword))
{
Error("'end for' or a statement expected.", lastReadToken);
SkipUntilFollow(Semicolon);
}
else
{
if (!Match(for_Keyword))
{
Error("'end for' expected.", lastReadToken);
SkipUntilFollow(Semicolon);
}
}
}
}
for_statement = new AST_for_statement(identifier, from, to, statement_list);
DecrementDepth();
return(for_statement);
}
public virtual void Visit(AST_identifier identifier)
{
}