public static Either <ParseException, Pair <List <IToken>, ForLoopNode> > Parse(List <IToken> tokens, SymT symT, IScopedTable <IEntityType, string> parentTypeTable)
{
Console.WriteLine("ForLoopNode");
SymT NewSymT = new SymT(symT);
if (tokens.Count < 1)
{
return(NotAForLoopException);
}
if (!(tokens[0] is ForKeywordToken))
{
return(NotAForLoopException);
}
tokens = tokens.Skip(1).ToList();
if (tokens.Count < 1)
{
return(NotAForLoopException);
}
if (!(tokens[0] is IdentifierToken))
{
return(NotAForLoopException);
}
IdentifierToken identifier = (IdentifierToken)tokens[0];
var typeTable = new Dictionary <string, IEntityType>();
typeTable.TryAdd(
identifier.Lexeme,
new VariableType(new PrimitiveTypeRepresentation(new IntegerTypeNode()))
);
tokens = tokens.Skip(1).ToList();
var result = new ForLoopNode(
identifier, null, null, NewSymT, typeTable, parentTypeTable);
var maybeRange = RangeNode.Parse(tokens, result);
if (NewSymT.Contain(identifier))
{
// TODO: return an exception instead
Console.WriteLine("Repeating identifier in the same scope");
}
else
{
NewSymT.Add(identifier);
}
if (maybeRange.IsLeft)
{
return(maybeRange.LeftToList()[0]);
}
RangeNode range = maybeRange.RightToList()[0].Second;
tokens = maybeRange.RightToList()[0].First;
if (tokens.Count < 1)
{
return(NotAForLoopException);
}
if (!(tokens[0] is LoopKeywordToken))
{
return(NotAForLoopException);
}
tokens = tokens.Skip(1).ToList();
var maybeBody = BodyNode.Parse(tokens, NewSymT, result);
if (maybeBody.IsLeft)
{
return(maybeBody.LeftToList()[0]);
}
BodyNode body = maybeBody.RightToList()[0].Second;
tokens = maybeBody.RightToList()[0].First;
if (tokens.Count < 1)
{
return(NotAForLoopException);
}
if (!(tokens[0] is EndKeywordToken))
{
return(NotAForLoopException);
}
tokens = tokens.Skip(1).ToList();
while (tokens.Count > 0)
{
if (tokens[0] is NewLineSymbolToken || tokens[0] is CommentToken ||
tokens[0] is SemicolonSymbolToken)
{
tokens = tokens.Skip(1).ToList();
}
else
{
break;
}
}
result.Range = range;
result.Body = body;
return(new Pair <List <IToken>, ForLoopNode>(tokens, result));
}