Haskell-Snippets

Haskell-Snippets is a collection of YASnippet Haskell snippets for Emacs.

Installation

Enable the Emacs package manager and make sure the melpa package repository is set up.

(require 'package)
(add-to-list 'package-archives
             '("melpa" . "http://melpa.milkbox.net/packages/") t)
(package-initialize)

M-x package-install haskell-snippets

Add the following to your Emacs config:

(require 'haskell-snippets)

Snippets may have to be recompiled and reloaded in Emacs if YASnippet is already in use:

M-x yas-recompile-all M-x yas-reload-all

Haskell snippts should now be available to use! In a haskell-mode buffer, type fn<TAB>. A prompt should appear asking which fn snippet to expand.

I highly recommend using YASnippet with ido-mode. Configure Emacs:

(setq-default yas-prompt-functions '(yas-ido-prompt yas-dropdown-prompt))

This is important so that alternatives (like import vs. import qualified) can quickly be selected with a single key stroke.

Available Expansion Keys

• new - newtype
• mod - module [simple, exports]
• main - main module and function
• let - let bindings
• lang - language extension pragmas
• opt - GHC options pragmas
• \ - lambda function
• inst - instance declairation
• imp - import modules [simple, qualified]
• if - if conditional [inline, block]
• <- - monadic get
• fn - top level function [simple, guarded, clauses]
• data - data type definition [inline, record]
• => - type constraint
• {- - block comment
• case - case statement

Design Ideals

• Keep snippet keys (the prefix used to auto-complete) to four characters or less while still being as easy to guess as possible.

• Have as few keys as possible. The more keys there are to remember, the harder snippets are to use and learn.

• Leverage ido-mode when reasonable. For instance, to keep the number of snippet keys to a minimum as well as auto complete things like Haskell Langauge Extension Pragmas. When multiple snippets share a key (ex: fn), the ido-mode prompts are unique to one character (ex: guarded function and simple function are g and s respectively).

Authors

This code is written and maintained by Luke Hoersten, luke@hoersten.org.