GNU ELPA - hcel


Haskell codebase explorer / cross referencer
hcel-1.0.0.tar, 2022-Oct-05, 130 KiB
Yuchen Pei <>
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To install this package, run in Emacs:

M-x package-install RET hcel RET

Full description

hc.el (or hcel in ELPA) is a client to hcel and an Emacs package for Haskell code browsing and exploring. Features include:

  • Jump to definition across packages
  • Find references across packages
  • Search identifiers in a package or globally
  • Highlight the identifier at point
  • Browse packages, modules and identifiers in an outline mode buffer
  • Eldoc integration, showing type and documentation of the identifier at point, or the selected expression.
  • Syntax highlight, either with builtin font-locks or haskell-mode
  • Show info about an identifier in a help buffer
  • Integration with haddorg, allowing jumps between identifier definition site and its org entry in documentation generated by haddorg.

1 Install

Clone this repo, and add to load path (assuming you clone to ~/.emacs.d):

cd ~/.emacs.d
git clone
(add-to-list 'load-path "~/.emacs.d/hc.el")

You'll also need an hcel server. To host one yourself, clone the repo and follow the instructions there.

Once you have a server set up (say at localhost:8080) and serving source info about indexed packages, do the following and you are all set.

(require 'hcel)
(setq hcel-host "localhost:8080")

2 Use

There are several entry points:

  • hcel opens up an hcel-outline mode buffer, where you can browse all packages, modules and identifiers in outline mode, and open any module source or jump to the definition of any identifier you like;
  • hcel-package prompts you for a package id, followed by a module path, to open the module source.
  • hcel-global-ids lets you search for identifiers globally, and either jump to the source (in case of a hit) or display search results.
  • hcel-help lets you search for identifiers globally and displays the result in a help buffer.


Most of these TODOs likely require changes to the server program.

  • Awareness of all modules exporting an identifier (like hoogle)
  • Requesting server to index a new package, or re-index an updated one.

4 Contact and Copyright

hc.el is maintained by Yuchen Pei <> and covered by GNU AGPLv3+. You may find the license text in a file named COPYING.agpl3 in the project tree.