private Expression ParseAtomExpressionExpression(int i)
{
var e = ParseAtomExpression(i);
if (e == null)
{
return(null);
}
var t = _lex.GetToken(e.End);
while (t.TokenType == TokenType.LeftSquareBracket ||
t.TokenType == TokenType.Dot)
{
if (t.TokenType == TokenType.LeftSquareBracket)
{
var r = ParseExpression(t.End);
if (r == null)
{
throw ThrowHelper(t.End, ParsingError.MissingExpression);
}
var endToken = _lex.GetToken(r.End);
if (endToken.TokenType != TokenType.RightSquareBracket)
{
throw ThrowHelper(r.End, ParsingError.MissingEndOfSubscript);
}
e = new BinaryExpression(e.Start, endToken.End,
BinaryOperator.Subscript, e, r);
t = _lex.GetToken(endToken.End);
}
else if (t.TokenType == TokenType.Dot)
{
var tr = _lex.GetToken(t.End);
if (tr.TokenType != TokenType.Symbol)
{
throw ThrowHelper(t.End, ParsingError.InvalidSymbol);
}
var r = new SymbolExpression(tr.Start, tr.End,
_s.Substring(tr.Start, tr.End - tr.Start));
e = new BinaryExpression(e.Start, r.End,
BinaryOperator.MemberAccess, e, r);
t = _lex.GetToken(r.End);
}
}
return(e);
}
private ExpressionValue EvaluateSymbol(Context ctx, SymbolExpression e)
{
if (ctx.Locals.ContainsKey(e.Symbol))
{
return(AsValue(ctx.Locals[e.Symbol]));
}
else if (ContainsValue(ctx.Globals, e.Symbol))
{
return(GetValue(ctx.Globals, e.Symbol));
}
else
{
return(ExpressionValue.Empty);
}
}
