Wolfgang Jeltsch
I would solve this problem by reducing the Prelude to just a core. List function could go, for example, (mostly) into Data.List.
There is a proposal to shrink the prelude to the minimum possible. I have just fleshed out some of the details, at the bottom of this page: http://hackage.haskell.org/trac/haskell-prime/wiki/Prelude Here are the details, reproduced for email discussion: Let the Prelude itself contain only entities that relate purely to functions - no other datatypes. module Prelude ( (->) , (.) , ($) , ($!) , flip , id , const , error , undefined , seq , asTypeOf ) Everything else that is currently in the Haskell'98 Prelude is re-distributed across a variety of small modules. Where a syntactic desugaring rule currently uses an entity from the Prelude, the new interpretation is that it uses whatever binding of that entity is in scope - if there is no such entity in scope, it is an error. For compatibility, we define a wrapper module called Prelude.Standard which re-exports the original Haskell'98 Prelude: module Prelude.Standard ( module Prelude , module Prelude.Num , module Prelude.Comparison , module Prelude.Monad , module Prelude.List , module Prelude.Maybe , module Prelude.Either , module Prelude.Tuple , module Prelude.IO , module Prelude.Text ) And here are the individual fragments: module Prelude.Num ( data Natural(..) , data Int(..) , data Int8(..) , data Int16(..) , data Int32(..) , data Int64(..) , data Word8(..) , data Word16(..) , data Word32(..) , data Word64(..) , data Integer(..) , data Float(..) , data Double(..) , type Rational , class Integral(..) , class Num(..) , class Fractional(..) , class Real(..) , class RealFrac(..) , class Floating(..) , class RealFloat(..) , gcd, lcm , fromIntegral, realToFrac , numericEnumFrom, numericEnumFromTo, numericEnumFromThen , numericEnumFromThenTo , (^), (^^), (%) , even, odd, subtract ) module Prelude.Comparison ( data Bool(..) , data Ordering(..) , class Eq(..) , class Ord(..) , class Enum(..) , class Bounded(..) , otherwise , (&&), (||), not, until ) module Prelude.Monad ( class Functor(..) , class Monad(..) , mapM, mapM_, sequence, sequence_, (=<<) ) module Prelude.List ( data [](..) , all, and, any, (++), break, concat, concatMap, cycle, drop, dropWhile , elem, filter, foldl, foldl1, foldr, foldr1, head, (!!), init, iterate , last, length, lines, lookup, map, maximum, minimum, notElem, null , or, product, repeat, replicate, reverse, scanl, scanl1, scanr, scanr1 , span, splitAt, sum, tail, take, takeWhile, unlines, unwords, words ) module Prelude.Maybe ( data Maybe(..) , maybe ) module Prelude.Either ( data Either(..) , either ) module Prelude.Tuple ( data ()(..) , data (,)(..) , data (,,)(..) , data (,,,)(..) , data (,,,,)(..) , data (,,,,,)(..) , data (,,,,,,)(..) , data (,,,,,,,)(..) , data (,,,,,,,,)(..) , data (,,,,,,,,,)(..) , data (,,,,,,,,,,)(..) , data (,,,,,,,,,,,)(..) , data (,,,,,,,,,,,,)(..) , data (,,,,,,,,,,,,,)(..) , data (,,,,,,,,,,,,,,)(..) , fst, snd , unzip, unzip3, zip, zip3, zipWith, zipWith3 , curry, uncurry ) module Prelude.IO ( data IO , data IOError(..) , data FilePath , ioError, userError, catch , print , putChar, putStr, putStrLn , getChar, getLine, getContents, interact , readFile, writeFile, appendFile, readIO, readLn ) module Prelude.Text ( data Char(..) , type String , class Read(..) , class Show(..) , type ReadS , type ShowS , read, reads, readParen, lex , shows, showString, showParen, showChar )