libghc-either-dev software package provides Either monad transformer, you can install in your Ubuntu 17.04 (Zesty Zapus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install libghc-either-dev
libghc-either-dev is installed in your system.
Make ensure the libghc-either-dev package were installed using the commands given below,
$ sudo dpkg-query -l | grep libghc-either-dev *
You will get with libghc-either-dev package name, version, architecture and description in a table
| Distro | Ubuntu 17 04 zesty zapus |
| Section | Haskell |
| Package | libghc-either-dev |
| Version | 4.4.1.1-3 |
| Description | Either monad transformer |
| Sub Section | haskell |