Install libghc-userid-doc by entering the following commands in the terminal:
sudo apt update sudo apt install libghc-userid-doc
Description:
The UserId type and useful instances for web development; documentation
Includes instances for SafeCopy, Lens, Boomerang, PathInfo and more . 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.github.com/Happstack/userid
Version: 0.1.2.8-1build5
Section: universe/doc