libghc-extra-doc 1.4.2-1 (amd64 binary) in ubuntu xenial

 Library of extra functions for the standard Haskell libraries. Most
 functions are simple additions, filling out missing functionality. A
 few functions are available in later versions of GHC, but this
 package makes them available back to GHC 7.2.
 .
 This package provides the documentation for a library for the Haskell
 programming language.
 See http://www.haskell.org/ for more information on Haskell.