i think this is what you want. untested:
pair: REP ATOM
| REP '[' block ']'
block: pair
| block pair
> Hello,
> sorry for an off-topic thing. But I guess somebody here could help me...
> I have a problem with bison grammer
>
> Having
>
> %token ATOM
> %left '+'
> %left REP
>
> and a grammar:
>
> block: ATOM
> | REP block
> | block '+' block
> ;
>
> is ok. Having another grammer:
>
> block: ATOM
> | REP block
> | block block %prec '+'
> ;
>
> has 2 shift/reduce conflicts, similar to
> state 7
>
> 5 block: REP block .
> 6 | block . block
>
> ATOM shift, and go to state 3
>
> ATOM [reduce using rule 5 (block)]
> $default reduce using rule 5 (block)
>
> block go to state 9
>
> or
> state 9
>
> 6 block: block . block
> 6 | block block .
>
> ATOM shift, and go to state 3
> REP shift, and go to state 4
>
> ATOM [reduce using rule 6 (block)]
> $default reduce using rule 6 (block)
>
> block go to state 9
>
> What I want is to have a parser that can read e.g. (the spaces are
> left out by lex, they are not in what bison sees; I only write them
> here for better readability)
> 12 Au 13 Cu 2 Ag
> the former grammer (REP is for repetition) is able to read
> 12 Au + 13 Cu + 2 Ag
> but I don't like those pluses, which are redundant.
>
> Also important: I have those 'block' non-terminals there, since I want
> to add another rule
> block: '[' block ']'
> so that I can use brackets and can parse things like
> 12 [ 2 Cu 3 Co]
>
> Could anyone explain to me what goes wrong?
> I can't figure it out...
>
> Thanks a lot
> Ruda
>
> PS.: the grammer is actually identical to a grammer that can evaluate
> expressions with +, *, and brackets, with usual operator precedence.
