Unlike Vim/Neovim, where there are snippet engines like ultisnips and other plugins. In Emacs, the de facto snippet engine is yasnippet.

# Installation and setup

Like vim-snippets for ultisnips, yasnippet-snippets provides the actual snippets for yasnippet.

Yasnippet and yasnippet-snippets can be easily installed via straight.el:

(straight-use-package 'yasnippet)
(straight-use-package 'yasnippet-snippets)

(yas-global-mode t) ;; activate yasnippet


# Check available snippets

To check the available snippets for the current mode, run command yas-visit-snippet-file and choose snippet to view. You can also run command yas-describe-tables, which will show a list of snippets and their trigger words in a separate buffer.

## The trigger shortcut

By default, the shortcut to trigger the expansion of a snippet is Tab. It can be easily changed, e.g., to change the shortcut to Meta-z, add the following config to init.el:

(define-key yas-minor-mode-map (kbd "M-z") 'yas-expand)


## Jump forward and backward

To jump forward and backward through the tabstop fields/positions, the default is to use Tab and Shift+Tab. You can customize via the following config:

;; use Meta-j and Meta-k to jump between fields
(define-key yas-keymap (kbd "M-j") 'yas-next-field-or-maybe-expand)
(define-key yas-keymap (kbd "M-k") 'yas-prev-field)


# Create custom snippets

The snippets are usually organized into different modes, which is kinda like filetypes in Vim/Neovim. For custom snippets, we can put under the directory ~/.emacs.d/snippets.

## Snippet for a specific mode

To create a snippet for markdown-mode, create a directory markdown-mode under ~/.emacs.d/snippets and create a new file there (the file name does not really matter)1. To create a snippet for markdown front matter like what is done here using ultisnips, use the following snippet:

# -*- mode: snippet -*-
# name: meta data
# contributor: jdhao <jdhao@hotmail.com>
# key: meta
# --
---
title: "${1:TITLE}" date: (format-time-string "%Y-%m-%dT%H:%M:%S%:z") tags: [${2:TAG}]
categories: [${3:CATEGORY}] ---$0


The key field is the trigger word for this snippet, i.e., you type meta and press the trigger key to expand the snippet. The string inside the two backtick will be interpreted by the Emacs lisp interpreter and the result will be inserted there.

## General Snippets (fundamental-mode snippets)

To write a snippet applicable to different modes, we can put it under the directory named fundamental-mode.

Check here on how to write a snippet for yasnippet.

# Override an existing snippet

To override an existing snippet provided by yas-snippets, create a new snippet for the same mode with the same name. For example, to override link, use the following snippet instead:

# -*- mode: snippet -*-
[${1:TEXT}](${2:URL})

The name field must be the same with the existing snippet you want to override.
1. You can also run command yas-new-snippet to create a new snippet. ↩︎