Install libghc-syb-doc by entering the following commands in the terminal:
sudo apt update sudo apt install libghc-syb-doc
Description:
Generic programming library for Haskell; documentation
This package contains the generics system known as "Scrap Your Boilerplate". It defines the "Data" class of types permitting folding and unfolding of constructor applications, instances of this class for primitive types, and a variety of traversals. . This package provides the documentation for a library for the Haskell programming language. See http://www.haskell.org/ for more information on Haskell.
Homepage: http://www.cs.uu.nl/wiki/GenericProgramming/SYB
Version: 0.7-1
Section: universe/doc