private void DequeueIdentifierUsage(Node parent, string error)
{
Token token = Dequeue();
if (token?.Type == NodeType.Identifier)
{
Identifier identifier;
SymbolLookup lookup = symbolTable.Get(token.Value);
if (lookup == null)
{
identifier = new Identifier(token.Value, Peek() == "." ? IdentifierKind.Class : IdentifierKind.Subroutine, false);
}
else
{
identifier = new Identifier(lookup.Name, lookup.Kind, false, lookup.Number);
identifier.ClassType = lookup.ClassType;
}
parent.AddChild(identifier);
if (Peek() == "[")
{
DequeueSymbol(parent, "[");
parent.AddChild(ParseExpression());
DequeueSymbol(parent, "]");
}
}
else
{
string suffix = token == null ? ", reached end of file instead" : $", got {token} instead";
throw new ApplicationException(error + suffix);
}
}
public SymbolLookup Add(string name, IdentifierKind kind, string classType)
{
SymbolLookup symbol = null;
if (IsFieldOrStatic(kind))
{
int number = classSymbols.Count(s => s.Kind == kind);
symbol = new SymbolLookup {
Name = name, Kind = kind, Number = number, ClassType = classType
};
classSymbols.Add(symbol);
}
if (IsArgumentOrVar(kind))
{
int number = subroutineSymbols.Count(s => s.Kind == kind);
if (isMethod && kind == IdentifierKind.Argument)
{
number++;
}
symbol = new SymbolLookup {
Name = name, Kind = kind, Number = number, ClassType = classType
};
subroutineSymbols.Add(symbol);
}
return(symbol);
}
private void DequeueIdentifierDeclaration(Node parent, IdentifierKind kind, string classType, string error)
{
Token token = Dequeue();
if (token?.Type == NodeType.Identifier)
{
Identifier identifier;
if (SymbolTable.IsClassOrSubroutine(kind))
{
identifier = new Identifier(token.Value, kind, true);
}
else
{
SymbolLookup symbolLookup = symbolTable.Add(token.Value, kind, classType);
if (symbolLookup != null)
{
identifier = new Identifier(symbolLookup.Name, symbolLookup.Kind, true, symbolLookup.Number);
}
else
{
identifier = new Identifier(token.Value, IdentifierKind.Subroutine, true);
}
}
identifier.ClassType = classType;
parent.AddChild(identifier);
if (Peek() == "[")
{
DequeueSymbol(parent, "[");
parent.AddChild(ParseExpression());
DequeueSymbol(parent, "]");
}
}
else
{
string suffix = token == null ? ", reached end of file instead" : $", got {token} instead";
throw new ApplicationException(error + suffix);
}
}
public SymbolLookup Get(string name)
{
SymbolLookup subroutineSymbol = subroutineSymbols.SingleOrDefault(s => s.Name == name);
return(subroutineSymbol ?? classSymbols.SingleOrDefault(s => s.Name == name));
}