Necessary:

• ghc and a recent Haskell Platform (>= 2012 should do fine)
• cabal
• Cabal packages: base, bytestring, aeson, haskell-src-exts (== 1.14.*), haddock (cabal install aeson haskell-src-exts haddock)
• If you are using GHC 7.6, you might have trouble with too new versions of haddock; in that case, try cabal install haddock --constraint=haddock==2.13.2.1

Optional, but useful:

• ghc-mod (for import and LANGUAGE completions and type inference, cabal install ghc-mod)
• stylish-haskell (for code prettification, cabal install stylish-haskell)
• cabal-dev if you want to use it
• haskell-docs (for documentation in 'Symbol info' command, cabal install haskell-docs)
• hdevtools (or fork for windows) (for type inference, cabal install hdevtools)

1. Get Sublime Text 2: http://www.sublimetext.com/
2. Install the Sublime Package Control package: http://wbond.net/sublime_packages/package_control/installation
3. Use Package Control to install this package (SublimeHaskell)

In short: Press Shift-Ctrl-P and type haskell to explore all commands.

When editing Haskell source files that are part of a Cabal project, automatic error highlighting and enhanced auto-completion are available.

Each time you save, any errors in your program will be listed at the bottom of the window and highlighted in the source code.

All source files in the project are scanned when the change. Any symbols that they export are provided in the auto-complete suggestions.

To use cabal-dev instead of cabal, set use_cabal_dev to true (or use command "Switch Cabal/Cabal-Dev") and specify cabal-dev absolute path. Completion list will be rescanned and build will use cabal-dev.

Stylish-haskell can be used to stylish file or selected text.

Use Ctrl-Shift-R to go to declaration and Ctrl-K-I to show symbol info with documentation. These command are also available through context menu with right-click.

Command 'SublimeHaskell: Browse module' is similar to ghci's browse command

To show inferred types use Show type (ctrl-k ctrl-h ctrl-t) command.

To insert inferred type use Insert type (ctrl-k ctrl-h ctrl-i).

You can jump between the errors and warnings with F4 and Shift-F4. To show hidden error output, use command Show error panel (ctrl-alt-e)

You don't have to use SublimeHaskell's built-in build functionality.

If you prefer, you can disable them in the settings, and use plain Sublime Build Systems:

Save this to your ~/.config/sublime-text-2/Packages/User/cabal-custom.sublime-build to make a custom cabal build system:

{
  "cmd": ["cabal build --ghc-options='-O0 -hidir o0 -odir o0'"],  // append lib:myPackage or myexecutable here to only build certain cabal targets
  "shell": true,
  "file_regex": "^(\\S*?):(\\d+):(\\d+):$"  // this matches the output of ghc
}

For more options, look here.

Save this to your ~/.config/sublime-text-2/Packages/User/hdevtools.sublime-build to make hdevtools a build system:

{
  "cmd": ["/home/USERNAME/.cabal/bin/hdevtools", "check", "-g", "-Wall", "$file"],
  "file_regex": "^(.*?):(\\d+):(\\d+):",
  "selector": "source.haskell"
}

You can then build with Ctrl-B and jump between the errors with (Shift-)F4.

It is also useful to add this to your key bindings to redisplay the error panel at any time:

  { "keys": ["ctrl+alt+b"], "command": "show_panel", "args": {"panel": "output.exec"} }

The ModuleInspector is a program that looks at your Haskell environment to provide auto completion.

Depending on your environment, this may takes very long.

You can disable it with the "inspect_modules": false setting.