MOTIVATION

In Emacs Lisp (elisp), there is no native namespace system. While it has the convenient consequence, that the same symbol means the same everywhere (a boon for interactive features like M-x describe-function or M-x find-function), it also results in a lot of “boilerplate” re-typing of namespace prefix strings.

While implementations of macro-based namespaces such as names.el exist, they are bound to lack support for current or future interactive features, that depend on the presence of full function names in the source-code files.

This provisional package is meant to make working with namespace prefices more convenient in the meantime.

It is also meant for experimenting with what works.

USAGE

• Download myelisp-namespace-helper.el.

• Either

  • Copy/paste the contents into your .emacs file, or (preferably)

  • Put a statement

    (load-file "PATH/TO/myelisp-namespace-helper.el")
    

    into your .emacs file.

• Enable M-x myelisp-namespace-helper-mode in buffers, where you want to use it. Optionally, enable M-x myelisp-namespace-helper-global-mode.

• In emacs-lisp-mode or lisp-interaction-mode, insert a buffer-appropriate namespace prefix by pressing - once, while not already inside a symbol, and again for a private prefix according to the NAMESPACE-public-name and NAMESPACE--private-name covention.

  The --key doesn't insert a prefix

  • when typed after symbol characters,
  • when immediately followed by a number or whitespace,
  • when typed inside a string or comment, unless preceded by a backtick (`) or quote (') character, or
  • when inserted using quoted-insert (normally C-q -).

• Define a file variable myelisp-namespace-helper-prefix to override the default prefix.

With this code, prettify-symbols-mode collapses the namespace prefix into a highlighted hyphen, mirroring the input method.

For LaTeX, the @ character is expanded to NAMESPACE@, corresponding to the common convention for internal variables and macros. By default, myelisp-namespace-helper-global-mode affects only Emacs Lisp buffers. This behavior can be changed by customizing myelisp-namespace-helper-affected-modes-alist via M-x customize-variable.

CHANGELOG

2020-02-06 In order to support dash.el, the namespace prefix will be removed, if doing so results in a known function or variable.

2018-06-26 Added default entries for doctex-mode (i.e. .dtx-files).

2018-06-23.2 Made prefix character, and whether modes are affected by myelisp-namespace-helper-global-mode configurable via M-x customize-variable myelisp-namespace-helper-affected-modes-alist.

2018-06-23.1 Added support for LaTeX with the @ prefix character.

2018-06-14

• Created proper repository with separate README.md file from gist.
• Added line that properly activates global mode if enabled in the customization interface.

2018-06-12 Rewrote in terms of the post-self-insert-hook. Sadly, on the way the limited support for the eval-expression as only case of minibuffer usage was lost too.

The improvement, that now -1 or (- 1 2) can be typed without producing a prefix, is more important however.

Also merged CHANGELOG into the source file.

2018-06-10 Bugfix: Limited the faces that affect the - key; Previously show-paren-match face prevented insertion when cursor located immediately before a (.

2018-06-08 More documentation.

2018-06-07 Made file namespace-clean.

TODO: IMPROVEMENTS?

• Prettification, and maybe insertion, should possibly be limited to private--names by default. The programmer should remain aware of how verbose client code will see the “public” interface.

• This would also solve the issue of typing negative numbers or the - function without C-q prefix.

• Need to find way to support minibuffer. I currently have no general way of telling generally, if the read-request to the minibuffer wants a symbol/expression as completion.

WHAT DID NOT WORK

• Key ~. It is the least common printable ASCII character in Emacs's lisp code, but using the same key for inserting the prefix and for separating words in symbols proved a huge usability advantage.

• Double -- for prefix, triple --- for private prefix. Possibly a matter of training, but it felt wrong.

TODO: FUTURE PLANS

• Separate minor mode from prettify-symbols-mode.