until -package:numeric-prelude -package:streaming -package:util -package:snap-core -package:basic-prelude -package:hosc -package:singletons-base -package:utility-ht -package:scalpel-core -package:linear-base package:filepath

findFromEndUntil :: (Word16 -> Bool) -> ShortByteString -> Int
filepath System.OsPath.Data.ByteString.Short.Internal
Returns the length of the substring matching, not the index. If no match, returns 0.