-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 apfelmus wrote: > Mark T.B. Carroll wrote: >> I've been playing with Text.Parsers.Frisby to see how it stacks against >> other options and, while it's been great so far, I am finding that I >> can't encode a grammar where what's acceptable depends on what's already >> been parsed in some nontrivial way. >> [...] >> Is this supposed to not be possible in Frisby, or (quite likely) am I >> missing something that allows me to? > > It's intentionally impossible. Frisby uses a dynamic programming > approach that crucially depends on the fact that the grammar in question > is context-free (actually something related, but the effect is the > same).
Is that dependence crucial? What if it gained Monad operations that just weren't intended to be used very often, and maybe locally harmed performance a little where they are used? BTW: (P s) should be an instance of Applicative (which is already possible with Frisby's current code, just not there) (I prefer the aesthetics of Frisby-applicative code to many of the combinators it provides - I tried it a little sometime, not enough to send a darcs patch) Isaac -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFGXFZVHgcxvIWYTTURApl+AKClt8J1m+qkEG+qNSI4RSATmZfSkACfdJN8 4gLKaM/hKS85UgMsERoItRM= =dJx9 -----END PGP SIGNATURE----- _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe