Re: [Haskell-cafe] Re: Efficient parallel regular expressions

Excerpts from ajb's message of Wed Nov 05 03:59:03 +0100 2008:

G'day all.

Hi,

Quoting Achim Schneider :

...

Considering that he's talking about a mud, I figure the grammar is a quite straightforward

command = l[eft] | r[ight] | ... | t[ake] <item> | c[ast] <spell>

That is, I'd be very surprised if you even need more than two or three characters lookahead, much less backtracking.

In the case of a command followed by arguments, it would make more sense to use a keyword recogniser followed by a command-specific parser.

One suggestion follows.

Oops there is a bug in there: GHCI> keywordMatch [("a", 1), ("aa", 2)] "aa" Nothing The third equation of generateTrie' is missing a guard, namely k1 /= k2. generateTrie' [(k1:ks1,v1),(k2:ks2,v2)] | k1 /= k2 = Node2 k1 (generateTrie [(ks1,v1)]) k2 (generateTrie [(ks2,v2)]) Best regards, -- Nicolas Pouillard aka Ertai