Example #1
0
        public static LinkedListNode <Lexeme> TryParse(LinkedListNode <Lexeme> lexemes, out Var resultNode)
        {
            resultNode = null;
            if (lexemes.Value.Type != LT.IDENT)
            {
                return(lexemes);
            }
            resultNode = new Var {
                Token = lexemes.Value
            };

            var nextLexeme = lexemes.Next;

            if (nextLexeme.Value.Type == LT.OP_SQBRACKET_O)
            {
                nextLexeme = nextLexeme.Next;
                nextLexeme = BinaryExpr.TryParseExpr(nextLexeme, out var expr);
                if (expr == null)
                {
                    throw new Exception($"Opening square bracket found, but no array index at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
                }
                if (nextLexeme.Value.Type != LT.OP_SQBRACKET_C)
                {
                    throw new Exception($"Missing closing square bracket after array index at {nextLexeme.Value.File}:{nextLexeme.Value.Line}");
                }
                resultNode = new ArrayVar {
                    Token = lexemes.Value, Index = expr
                };
                return(nextLexeme.Next);
            }

            return(nextLexeme);
        }