[Haskell-cafe] Text search
gracjan at acchsh.com
Mon May 16 08:00:33 EDT 2005
Ketil Malde wrote:
> Gracjan Polak <gracjan at acchsh.com> writes:
>>find (isSuffixOf "needle") (inits "haystack")
> 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:
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.
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