Re: Newbie question...

Amund Trovåg wrote:
> Yes, thank you so much for that! This works, and I understand why it 
> should be like this.  :)
> The last problem I have now is the part of the expression that is 
> "relationName". In the language, the relationNames/relation expressions, 
> are always enclosed in parentheses like you show above. The parentheses 
> however, are not part of the actual string of the token, they are rather 
> there to show that it is a relation, and not attribute e.g.
>
> This problem seems similar to the one you just solved, but it doesn't 
> seem to be(at least not in my newb experience) :).
> I have defined the tokens
> | <LEFTPAR: "(">
> | <RIGHTPAR: ")">
> and <RELATION> is the same as the token <ID>, only a different tokenname.
>
> So I have:
> void project() #PROJECT:
> {Token t = new Token();}
> {// project + attribute name commalist(zero or more(*)) end with 
> //(relationname) and EOF=;
> (t=<PROJECT>) [attributeList()] Relation() {jjtThis.setToken(t.kind, 
> t.image);}
> }
> and the relation production:
> void Relation() #RELATION:
> {Token t = new Token();}
> {
>     t=<RELATION>{jjtThis.setToken(t.kind, t.image);}
> }
> In Relation() I want to do something like this:
> <LEFTPAR>t=<RELATION>{jjtThis.setToken(t.kind, t.image);}<RIGHTPAR>
> but this doesn't seem to work.
>
> When I write in the parser: project ssn, name(relationName); The parser 
> returns, "expecting <RELATION>". I get it to work if I define the 
> <RELATION> token to be enclosed by <LEFTPAR> and <RIGHTPAR>. Still, this 
> is not what I want. This token too, should have the string as the 
> relationName in itself, _without_ the parentheses.
>
> This may seem easy for some of you, but I would be happy if you could 
> point me in the right direction for this as well so I can get on with my 
> program.
>
> Thanks in advance,
>
> regards,
> Amund

After parsing name it then tries to match Relation(), the first token of
Relation is <RELATION> while the next token of the input is "(".

The answer is similar to the previous one. You need to change Relation()
to look for "(" <RELATION> ")".

--
Mike Atkinson
(to reply remove NO SPAM from the address).