Install libghc-hashable-doc by entering the following commands in the terminal:
sudo apt update sudo apt install libghc-hashable-doc
Description:
class for types that can be converted to a hash value; documentation
It defines a class, Hashable, for types that can be converted to a hash value. This class exists for the benefit of hashing-based data structures. The package provides instances for basic types and a way to combine hash values. . 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://github.com/tibbe/hashable
Version: 1.2.6.1-1
Section: universe/doc