[antlr-interest] How can I avoid "mismatched input" error?

[Andreas Meyer]

Gabriel Petrovay schrieb:
> Hi Tom,
>
> So in your solution I would have to do something like this:
>
> name1: Name1 | KEYWORD1 | KEYWORD2 | ... KEYWORDM;
> name2: Name1 | KEYWORD1 | KEYWORD2 | ... KEYWORDM;
> ...
> nameN: NameN | KEYWORD1 | KEYWORD2 | ... KEYWORDM;
>
> This is what I meant when I said scalable. If you have 50 keywords, I 
> think that the production for each name rule is simply too large. This 
> comes with the cost of very expensive parsing. Isn't it?
>
> Regards,
> Gabriel
>

Why would you need n times m entries? What do you mean by name1 ... N 
anyway? If you want to model a variable context of names seen so far, 
you cannot do it like this.

Btw,  your Name lexer rule should disallow empty strings. Dont be scared 
by the number of keywords. I have a parser that recognizes 800 keywords, 
and it works. You may encounter strange strings like time-outs when 
trying to compute the prediction DFA, though, if the language is 
ambiguous (which is the case with xquery, it seems). But if you are 
careful, it should work.

Andreas