libghc-wl-pprint-extras-dev software package provides free monad based on the Wadler/Leijen pretty printer, you can install in your Ubuntu 16.04 LTS (Xenial Xerus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install libghc-wl-pprint-extras-dev
libghc-wl-pprint-extras-dev is installed in your system.
Make ensure the libghc-wl-pprint-extras-dev package were installed using the commands given below,
$ sudo dpkg-query -l | grep libghc-wl-pprint-extras-dev *
You will get with libghc-wl-pprint-extras-dev package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | Haskell |
| Package | libghc-wl-pprint-extras-dev |
| Version | 3.5.0.5-3build1 |
| Description | free monad based on the Wadler/Leijen pretty printer |
| Sub Section | Haskell |