public Expr OnParseFor()
{
var tokenIt = _parser.TokenIt;
var initiatorToken = tokenIt.NextToken;
// <codeFor>
if (initiatorToken.Token == Tokens.For)
{
tokenIt.ExpectMany(Tokens.For, Tokens.LeftParenthesis);
var ahead = tokenIt.Peek(1);
if (ahead.Token == Tokens.In)
{
return(OnParseForEach());
}
}
var start = _parser.ParseStatement();
var condition = _parser.ParseExpression(Terminators.ExpSemicolonEnd);
tokenIt.Advance();
var name = tokenIt.ExpectId();
var increment = _parser.ParseUnary(name, false);
tokenIt.Expect(Tokens.RightParenthesis);
var expr = Exprs.For(start, condition, increment, initiatorToken) as BlockExpr;
ParseBlock(expr);
// </codeFor>
_parser.SetupContext(expr, initiatorToken);
return(expr);
}
public Expr OnParseForEach()
{
var tokenIt = _parser.TokenIt;
var initiatorToken = tokenIt.NextToken;
// <codeForEach>
if (initiatorToken.Token == Tokens.For)
{
tokenIt.ExpectMany(Tokens.For, Tokens.LeftParenthesis);
var ahead = tokenIt.Peek(1);
if (ahead.Token != Tokens.In)
{
return(OnParseFor());
}
}
var varname = tokenIt.ExpectId();
tokenIt.Expect(Tokens.In);
var sourceExpr = _parser.ParseExpression(Terminators.ExpParenthesisNewLineEnd, true, false, true, false, false);
tokenIt.Expect(Tokens.RightParenthesis);
var expr = Exprs.ForEach(varname, sourceExpr, initiatorToken) as BlockExpr;
ParseBlock(expr);
// </codeForEach>
_parser.SetupContext(expr, initiatorToken);
return(expr);
}
/// <summary>
/// Parses a block by first pushing symbol scope and then popping after completion.
/// </summary>
public void ParseBlock(IBlockExpr expr)
{
_parser.Context.Symbols.Push(new SymbolsNested(string.Empty), true);
expr.SymScope = _parser.Context.Symbols.Current;
var withPush = false;
if (expr is ForEachExpr)
{
var foreachExpr = expr as ForEachExpr;
if (foreachExpr.EnableAutoVariable)
{
var name = foreachExpr.VarName;
Exprs.WithPush(name);
withPush = true;
}
}
_parser.ParseBlock(expr);
_parser.Context.Symbols.Pop();
if (withPush)
{
Exprs.WithPop();
}
}
