ghc-doc binary package in Ubuntu Bionic amd64

 The Glorious Glasgow Haskell Compilation system (GHC) is a compiler for
 Haskell.
 .
 Haskell is "the" standard lazy functional programming language. The language
 definition and additional documentation can be found in the `haskell-doc'
 package. Alternatively, there is an online version at
 http://haskell.org/onlinereport/.
 .
 This package includes HTML, DVI and PS versions of the SGML-based
 documentation around GHC.

Source package