Re: [Haskell-cafe] Text search

Ketil Malde wrote:

Gracjan Polak writes:

...

find (isSuffixOf "needle") (inits "haystack")

Hmm...

While the result isn't exactly the same, I suspect using isPrefixOf and tails would be more efficient.

I need the data before and including my needle. Like this: ( ... needle ) ignored Or at least count of the first part. Or, best, pair of: (beforeandincluding,after). String is rather long (potentially infinite), so using reverse and tail could be a problem :)

...

This one is beautiful, but not very practical.

Unless you have very repetitive data and/or tiny alphabet, it is actually quite efficient, as the expected length of prefixes that need to be checked before a mismatch can be determined is small.

At least, I was unable to beat it with my (feeble attempts at) BM or KMP implementations.

-kzm