[Haskell-cafe] Text search

Graham Klyne GK at ninebynine.org
Mon May 16 05:57:36 EDT 2005


At 10:27 16/05/05 +0200, Gracjan Polak wrote:


>Hi,
>
>Simple question: I need a function that matches string in another string. 
>Something like:
>
>find (isSuffixOf "needle") (inits "haystack")
>
>This one is beautiful, but not very practical. Could anybody point me to 
>some haskell library that does some searching, using KMP for example?

[[
import List
foo = isPrefixOf (reverse "needle") (reverse "haystack with needle")
bar = isPrefixOf (reverse "needle") (reverse "haystack with pins")
]]

Seems to work.  And (by inspection) is linear in size of haystack.

#g


------------
Graham Klyne
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