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);
}