Haskell: Package management

Usually done with cabal or stack.

cabal

https://cabal.readthedocs.io/en/latest/cabal-commands.html

• Install a package: cabal install
• Update package index (ie, list of available packages): cabal update
• Upgrade cabal itself: cabal install cabal-install (Unverified)
• Build project: cabal build
• Build and run project: cabal run
• Open a REPL for the built project: cabal repl
• Open a REPL with some packages available:
  • cabal repl --build-depends package1, package2
  • cabal repl -b package1, package2
• Start a new project interactively: cabal init -i
• Build haddock documentation: cabal haddock
• Download a package without adding it to a project: cabal get <package-name>
• List all installed packages: cabal list --installed
  • Also ghc-pkg list
  • https://stackoverflow.com/questions/36953396/how-to-list-all-the-installed-packages-and-their-version-with-cabal

—

Example use:

cabal init -i
# Edit <name>.cabal:
#  - include dependencies in build-depends (seperated by commas)
cabal build

Install an executable tool

cabal install --install-method=copy <package-name>

The executable will be at ~/.cabal/bin/

Eg:

cabal install --install-method=copy pandoc
# Executable would be at ~/.cabal/bin/pandoc

Tests

• Install dependencies for testing: cabal install --enable-tests
• Run tests: cabal test

See:

• https://functional.works-hub.com/learn/basic-unit-testing-in-haskell-using-hunit-and-cabal-29e47
• http://gbacon.blogspot.com/2009/06/setting-up-simple-test-with-cabal.html
• https://jade.fyi/blog/cabal-test-dev-trick/
• https://yanhan.github.io/posts/2013-12-22-cabal-installing-test-dependencies/
• https://discourse.haskell.org/t/help-setting-up-cabal-project-with-hunit-tests/2306/5

New package example

cabal init
cabal update
cabal configure
cabal install
cabal build
cabal exec ghci