IDE-Haskell Atom package provides basic capabilities, as well as a backend for other Atom-Haskell packages to use.

Known conflicts

This package relies on grammar defined by language-haskell. Any other Haskell grammar packages (such as haskell-grammar) may conflict with it.


Package is fully configurable via Edit → Preferences → Packages → ide-haskell → Settings

You will likely need to specify full path to prettifier executable, at the very least.

You might also want to look into configuring haskell-ghc-mod and ide-haskell-cabal

Since version 1.0.0, some configuration options have been moved to backends, in particular, haskell-ghc-mod. Migration should be automatic, but please check if your configuration is correct just in case.

Keyboard shortcuts

Since version 1.0.0, most commands are provided by backends, in particular, haskell-ghc-mod and ide-haskell-cabal. Please revise your keymap accordingly.

Refer to sections on haskell-ghc-mod and ide-haskell-cabal for details

Ide-Haskell comes with little pre-specified keybindings, so you will need to specify your own, if you want those.

You can edit Atom keybindings by opening ‘Edit → Open Your Keymap’. Here is a template for all commands, provided by ide-haskell:

  'escape': 'ide-haskell:close-tooltip' #this is set by default


  '': 'ide-haskell:toggle-output'
  '': 'ide-haskell:next-error'
  '': 'ide-haskell:prev-error'

Changing output panel look

Changing output panel look can be achieved with Atom stylesheets. You can open your stylesheet with Edit → Stylesheet…

Syntax is Less. You can use the following selectors:

  • ide-haskell-panel – whole panel
  • ide-haskell-panel-heading – panel heading (control elements)
  • ide-hashell-panel-items – output area
  • ide-haskell-item-position – file/line/column of individual message
  • ide-haskell-item-description – message itself

Please note, that to change font face in ide-haskell-item-description, you need to target it specifically, or use !important specifier.

For example, to change font size in whole panel:

ide-haskell-panel {
  font-size: 18pt;

Or only in output area:

ide-haskell-panel-items {
  font-size: 18pt;

To change font face in panel heading:

ide-haskell-panel-heading {
  font-family: "Comic Sans MS";

To change font face in messages themselves:

ide-haskell-item-description {
  font-family: "Fira Mono";

You are free to write any CSS, of course. Bear in mind, however, that any selectors not listed above are subject to sudden change.

Using atom-linter for output

You can use linter package for displaying some messages. Install linter package, and then change messageDisplayFrontend in ide-haskell settings to linter. Restart Atom.

Advanced configuration (since v2.2.0)

Some ide-haskell settings are root scope-sensitive, meaning they can have different values defined in config depending on editor grammar.

Atom Flight Manual gives a brief introduction into scoped settings here, but here’s a short refresher.

You can define setting overrides in your config file (Edit → Config…) under specific scope selectors. For example, imagine this is your config:

    stylishHaskellPath: "stylish-haskell"

Now, consider you would like to use hindent, but only for Literate Haskell files (since stylish-haskell doesn’t support lhs). You can do that by extending your config like so:

    stylishHaskellPath: "stylish-haskell"
    stylishHaskellPath: "hindent"

You can learn scope name for a given grammar by opening a file using that grammar and running editor:log-cursor-scope command. The first (topmost) entry in the message would be the root scope, the rest are syntax scopes.

Bear in mind ide-haskell isn’t sensitive to syntax scopes (since it’s either overly complicated to support or doesn’t make much sense).

Here’s a list of settings that are sensitive to root scope:

  • onSavePrettify
  • onSavePrettifyFormats
    • source*c2hs
    • source*cabal
    • source*hsc2hs
    • source*haskell
    • text*tex*latex*haskell
    • source*hsig
  • expressionTypeInterval
  • onCursorMove
  • stylishHaskellPath
  • stylishHaskellArguments
  • cabalPath

This list can be incomplete.