Introduction to Emacs Tempo Code Templates

Recently I removed yasnippets from my Emacs config as I rarely used the most of the snippets. Probably my own fault, when I started using yasnippets I downloaded a large repo of premade snippet definitions which meant I suddenly had a ton of keywords. Over the years I deleted many of ones I triggered by accident and found myself only using a handful of templates regularly.

When I learned Emacs has a built in template system, tempo, I figured this was a good time to try it out. I've been porting my few snippets over to tempo.el.

Since tempo is included with Emacs all you need to do is require it to enable it.

(require 'tempo)
(setq tempo-interactive t) ; Enable interactive prompts etc

The package is really cool, although it is not documented very well by Emacs standards. The explanation in the Emacs manual barely gives you any idea where to start. You need to dig around the tempo.el source file to read the commentary section and docstrings. From there I discovered there is a partially complete info manual available on David Kågedal's website.

I found the examples on the Emacs Wiki the most helpful. Along with that and the tempo-define-template docstring I was able to start building some templates. A basic template definition looks like this:

(tempo-define-template "insert-lambda"
                       '("(lambda (" (p "Arguments: ") ")" n> p ")" n)
                       "lambda"
                       "Insert a lambda function.")

Going line by line this means

1. Template name.
2. Template definition, tempo defines several default keywords that can be interpreted to do different things.
   • p — prompt user for input.
   • n — insert new line
   • n> — insert new line and indent
3. Template keyword.
4. Template docstring explanation.

For every tempo template defined an interactive function is automatically generated named "tempo-template" + "your-template-name". So you can run M-x tempo-template-insert-lambda and it will insert the template into your current buffer. This is really nice since I can use vertico to look-up my templates quickly without remembering a keyword.

If you want automatic expansion of the keywords like yasnippets that can be enabled by calling the function in an abbrev definition. Just make sure you have abbrev-mode on in the mode you are using.

(define-abbrev emacs-lisp-mode-abbrev-table "lambda" ""
  'tempo-template-insert-lambda)

Note the empty string "" which is required since this is not expanding to a normal word.

  (tempo-define-template "elisp-header"
    '(";;; " (file-name-nondirectory (or buffer-file-name "")) " --- "
      (p "Short Description: ")" -*- lexical-binding: t -*-

;; Copyright (C) 2025 Thomas Ingram

;; Author: Thomas Ingram <thomas@taingram.org>
;; Version: 0.1
;; Package-Requires: ((emacs \"30.1\"))
;; Homepage: https://git.sr.ht/~taingram/
;; Keywords:

;; This file is NOT part of GNU Emacs

;; This file is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 3, or (at your option)
;; any later version.

;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; For a full copy of the GNU General Public License
;; see <http://www.gnu.org/licenses/>.

;;; Commentary:

;;; Code:

(provide '" (file-name-base (or buffer-file-name "")) ")

;;; " (file-name-with-extension (or buffer-file-name "")) " ends here")
    nil
    "Insert documentation skeletion for a Emacs Lisp file.")