Re: Looking for formal definition of LALR(k)

KPRASAD.US.ORACLE.COM wrote:


> are you aware of a grammar that can be parsed by LR(k) and not LALR(k)?
> pl. provide examples
> thanks
> -kama


I don't have my dragon book next to me :), but I'll try to reconstruct the
example they gave: S -> aAa | aBb | bAb | bAa A -> c
        B -> c
The LR(k) parser will have two states {[A->c.|a],[B->c.|b]} and
{[A->c.|b],[B->c.|a]}, among others. When merged, they produce the LALR(k)
state {[A->c.|a,b],[B->c.|a,b]} with overlapping lookahead sets (i.e.,
reduce-reduce conflicts).


Zem

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