How to insert kbd macros in Yas-snippets?

Question

I'm trying to learn how to:

1. Define a kbd-macro, (here I'm using kbd-macros, because I'm bad at elisp currently).
2. Letting that to be executed when yas-snippet to expand. (here I'm struggling with)

---

My current state: I want to make following in latex equation. First write a_x / then press Tab to get \frac{a_x}{} (in here / as yas-snippet key).

# -*- mode: snippet -*-
# name: 1slash-frac_one_word
# key: /
# type: command
# --
(fset 'gry-test-frac-kbdmacro
   (kmacro-lambda-form [C-left ?\\ ?f ?r ?a ?c ?\{ C-right ?\} ?\{ ?\} left return return up tab] 0 "%d"))
(gry-test-frac-kbdmacro)

Basically, I first defined kbd-macro, and then inserted it's definition to the snippet, and then running it. This works.

---

My concerns/tries: Every time this snippet expands, gry-test-frac-kbdmacro gets defined again and again. Which seems to me inefficient. Also I don't want to write it's definition in other places like init.el. So tried following:

# -*- mode: snippet -*-
# name: 1slash-frac_one_word
# key: /
# type: command
# --
(kmacro-lambda-form [C-left ?\\ ?f ?r ?a ?c ?\{ C-right ?\} ?\{ ?\} left return return up tab] 0 "%d")

Basically, I tried to run the things inside of the macro definition (without defining it). However this doesn't work.

---

• Could you explain me why 2-nd snippet doesn't work?
• And Is there any way to run what's inside of macro without defining it first?

Answer 1

In order to run a macro without binding it to a name, use execute-kbd-macro. In your example, this would be:

(execute-kbd-macro [C-left ?\\ ?f ?r ?a ?c ?\{ C-right ?\} ?\{ ?\} left return return up tab])

Your second snippet creates a function, it needs to be evaluated for it to take effect. The "lambda-form" part refers to an anonymous function as the keyword lambda is used to define anonymous functions. See https://www.gnu.org/software/emacs/manual/html_node/elisp/Anonymous-Functions.html

Answer 2

The second snippet doesn't work because all you're doing is defining the keyboard macro lambda form; you're not doing anything with it. Use execute-kbd-macro as @Arktik suggests (see C-h f execute-kbd-macro). If you want to be more "lispy" you could do a snippet like the following:

# type: command
# key: /
# name: test2
# --
(backward-word)
(insert "\\frac{")
(forward-word)
(insert "}{}")
(left-char)

Note that yasnippet will wrap that in a progn on save.

But personally I wouldn't do that. I'd type my numerator, select backwards over it, then execute my snippet. Something like:

# name: test
# binding: C-c C-y
# --
\frac{`yas-selected-text`}{$1} $0

Note that you can't trigger the snippet via key:, you need to set a keybinding C-c C-y in this example.

But I wouldn't even do that. I'd just use the default latex-mode "frac" snippet which is:

# -*- mode: snippet -*-
# name: frac
# key: frac
# --
\frac{${1:numerator}}{${2:denominator}}$0

If you find yourself doing a lot of "repetitive but slightly different" text, you might want to check out Auto-YASnippet which describes itself as a hybrid of keyboard macros and YASnippet.