Install libghc-regexpr-doc by entering the following commands in the terminal:
sudo apt update sudo apt install libghc-regexpr-doc
Description:
Regular expression library like Perl/Ruby; documentation
This package contains Haskell functions for regular expressions. . 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://homepage3.nifty.com/salamander/second/projects/regexpr/
Version: 0.5.4-11build3
Section: universe/doc