private static Executable ParseFor(Parser parser, TokenStream tokens, Executable owner)
{
Token forToken = tokens.PopExpected("for");
tokens.PopExpected("(");
if (Parser.IsValidIdentifier(tokens.PeekValue()) && tokens.PeekValue(1) == ":")
{
Token iteratorToken = tokens.Pop();
if (Parser.IsReservedKeyword(iteratorToken.Value))
{
throw new ParserException(iteratorToken, "Cannot use this name for an iterator.");
}
tokens.PopExpected(":");
Expression iterationExpression = ExpressionParser.Parse(tokens, owner);
tokens.PopExpected(")");
IList <Executable> body = Parser.ParseBlock(parser, tokens, false, owner);
return(new ForEachLoop(forToken, iteratorToken, iterationExpression, body, owner));
}
else
{
List <Executable> init = new List <Executable>();
while (!tokens.PopIfPresent(";"))
{
if (init.Count > 0)
{
tokens.PopExpected(",");
}
init.Add(Parse(parser, tokens, true, false, false, owner));
}
Expression condition = null;
if (!tokens.PopIfPresent(";"))
{
condition = ExpressionParser.Parse(tokens, owner);
tokens.PopExpected(";");
}
List <Executable> step = new List <Executable>();
while (!tokens.PopIfPresent(")"))
{
if (step.Count > 0)
{
tokens.PopExpected(",");
}
step.Add(Parse(parser, tokens, true, false, false, owner));
}
IList <Executable> body = Parser.ParseBlock(parser, tokens, false, owner);
return(new ForLoop(forToken, init, condition, step, body, owner));
}
}