http://hackage.haskell.org/trac/ghc/ticket/1126 Proposal to create a new module Data.String, containing IsString(fromString), in the base package. This would be used by the overloaded strings extension (-foverloaded-strings in GHC). Deadline: 28 Feb 2007 Here's the meat of the patch: hunk ./Data/String.hs 1 +{-# OPTIONS_GHC -fno-implicit-prelude #-} +----------------------------------------------------------------------------- +-- | +-- Module : Data.String +-- Copyright : (c) The University of Glasgow 2007 +-- License : BSD-style (see the file libraries/base/LICENSE) +-- +-- Maintainer : libraries@haskell.org +-- Stability : experimental +-- Portability : portable +-- +-- Things related to the String type. +-- +----------------------------------------------------------------------------- + +module Data.String ( + IsString(..) + ) where + +#ifdef __GLASGOW_HASKELL__ +import GHC.Base +#endif + +-- | Class for string-like datastructures; used by the overloaded string +-- extension (-foverloaded-strings in GHC). +class IsString a where + fromString :: String -> a + +instance IsString [Char] where + fromString xs = xs Thanks Ian