until -package:numeric-prelude -package:language-bash -package:base-compat -package:utility-ht -package:hosc -package:linear-base -package:scalpel-core -package:varying -package:rattletrap -package:singletons-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.