Plan 9 from Bell Labs’s /usr/web/sources/contrib/fernan/nhc98/src/prelude/PreludeText/Read.hs
module Prelude where read :: (Read a) => String -> a read s = case [x | (x,t) <- reads s, ("","") <- lex t] of [x] -> x [] -> error "Prelude.read: no parse" _ -> error "Prelude.read: ambiguous parse"