Atom + Stack = no globally installed GHC/packages

When doing Haskell programming

• Stack keeps my operating system clean of globally installed compilers and packages
• atom-haskell allows me to use ghc-mod, hlint, and stylish-haskell without leaving the editor

Stack

• Get Stack
• Go to some folder (could be empty, or an existing project)
• Create a Stack.yaml file with just a line: resolver: lts-5.17 or later, as shown in https://www.stackage.org/lts/
• Execute stack setup

The output should look like this:

$ stack setup
Downloaded lts-5.17 build plan.
Caching build plan
Fetching package index ...remote: Counting objects: 213332, done.
remote: Compressing objects: 100% (171913/171913), done.
Receiving objects: 100% (213332/213332), 49.84 MiB | 1.79 MiB/s, done.-reused 0

Resolving deltas: 100% (56842/56842), completed with 1 local objects.
From https://github.com/commercialhaskell/all-cabal-hashes
 * [new tag]         current-hackage -> current-hackage
Fetched package index.
Populated index cache.
Preparing to install GHC to an isolated location.
This will not interfere with any system-level installation.
ghc-7.10.3:   15.89 MiB / 128.40 MiB ( 12.37%) downloaded...

GHC installed to [..]\AppData\Local\Programs\stack\x86_64-windows\ghc-7.10.3\
stack will use a locally installed GHC
For more information on paths, see 'stack path' and 'stack exec env'
To use this GHC and packages outside of a project, consider using:
stack ghc, stack ghci, stack runghc, or stack exec

• In the same directory as Stack.yaml execute stack build ghc-mod hlint stylish-haskell

atom-haskell

• Install Atom
• Install atom-haskell via apm: apm install language-haskell ide-haskell ide-haskell-cabal haskell-ghc-mod autocomplete-haskell haskell-pointfree haskell-debug
• Build stylish-haskell, ghc-mod, pointfree and pointful:

  stack build stylish-haskell
  stack build ghc-mod
  stack build pointfree
  stack build pointful
  

• Toggle haskell-pointfree via ctrl+alt+shift+f
• Toggle haskell-debug via ctrl-shift-p. To break on exceptions, launch the command palette, type in set break on exception, press enter and select the appropriate option.

That’s it - Happy Haskell programming!