~singpolyma/cheogram

ref: 3bd9c3870d41e3af2f469f2a3904025aef29a767 cheogram/UniquePrefix.hs -rw-r--r-- 425 bytes
3bd9c387Stephen Paul Weber -O2 takes too much RAM for CI 1 year, 2 months ago
                                                                                
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module UniquePrefix where

import Data.List
import qualified Data.Set as S
import qualified Data.Text as T
import qualified Data.CaseInsensitive as CI

uniquePrefix txts = helper [] $ map (S.fromList . map CI.mk . tail . T.inits) txts

helper done (prefixes:otherPrefixes) =
	(foldl' S.difference prefixes (done ++ otherPrefixes)) : helper (prefixes:done) otherPrefixes
helper _ [] = []

--ALT: https://pastebin.com/hFKdZw2g