YASnippet list my email questions please!

Too long; didn't read

In this post I show how to make a template to answer questions in email one step at the time and I present a workaround to modifying YASnippet templates according to the context you are working in.

The problem

I like to not forget to answer questions in my emails. Sometimes though they are scattered around and I just miss them. So I thought: a computer is a better finder than me, and this seems a good use case for a YASnippet!

Well, after a first draft this was not as easy as I thought: the issue is that emails may have as many questions as the sender likes. YASnippets are instead static pieces of string that get expanded when you need. You cannot force all emails to have a single question (you can ignore the others, but that's not what I want).

What I need is for the template show me all the questions and go through them one at the time in order of appearance.

So this is the snippet I started with to handle only the first question:

# -*- mode: snippet -*-
# name: mail-with-question-snippet
# key: q
# --

Hi ${1:Somebody},

${2: some intro text}
${3:`(first (my/pick-questions-in-mail))`}

$0

Bye!

It is a problem indeed

And apparently I was not the first to wish for this dynamic definition of YASnippets, these are the relatable issues I could find:

And apparently the creator of the project is looking into a major refactor to make this easy to do from quite some time.

With this I thought time to try something different!

And there is a solution

So the interesting bit is that snippets can be overridden dynamically. Your snippet files get loaded by YASnippet and then live in memory. The function yas-define-snippets lets you (re)define snippets for a major-mode. That's amazing news: with a bit of plumbing we can redefine our snippet dynamically.

So first step, save a partial snippet, in our case in the mu4e-compose-mode folder of YASnippet:

# -*- mode: snippet -*- name: mail-with-question-snippet key: q --

Hi ${1:Somebody},

${2: some intro text}
${3:`(first (my/pick-questions-in-mail))`}

$0

Bye!

Then, define a transformation, in our case how to retrieve questions from an email:

(defun my/split-string-in-sentences (string)
  (--> string
       (s-replace "\n" "" it)
       (with-temp-buffer
         (insert it)
         (goto-char (point-min))
         (while (not (eq (point) (point-max)))
           (forward-sentence)
           (insert "\n"))
         (buffer-substring-no-properties (point-min) (point-max)))
       (s-split "\n" it)
       (mapcar 's-trim it)))

(defun my/only-questions (sentences)
  (--filter (s-suffix-p "?" it)  sentences))

(defun my/pick-questions-in-text (string)
  (--> string
       my/split-string-in-sentences
       my/only-questions))

(defun my/pick-questions-in-mail ()
  (interactive)
  (--> (mu4e-message-field mu4e-compose-parent-message :body-txt)
       (s-split "\n" it)
       (--remove (s-prefix-p "> " it) it)
       (s-join " \n " it)
       my/pick-questions-in-text))

(defun my/pick-questions-in-buffer ()
  (interactive)
  (my/pick-questions-in-text (buffer-substring-no-properties (point-min) (point-max))))

(defun my/yas-mail-with-questions-snippet ()
  (let ((unique-name-snippet (s-concat "mail-snippet-question-" (format-time-string "%Y%m%d%H%M%S")))
        (questions (my/pick-questions-in-mail)))
    (-->
     (s-concat
      "Hi ${1: somebody`},\n\n${2: some intro text}\n"
      (apply
       's-concat
       (--map
        (let ((index (+ 3 (car it)))
              (question (cdr it)))
          (format "${%s:%s}\n\n" index question))
        (-zip (number-sequence 0 (length questions)) questions)))
      "$0\n\n"
      "Bye!")
     (yas/expand-snippet it))))

(defun my/update-q-snippet ()
  (when mu4e-compose-parent-message
    (message "updating!")
    (let* ((questions (my/pick-questions-in-mail))
           (snippet
            (s-concat
             "Hi ${1:`(bjm/mu4e-get-names-for-yasnippet)`},\n\n${2: Nice to hear that!}\n"
             (apply
              's-concat
              (--map
               (let ((index (+ 3 (car it)))
                     (question (cdr it)))
                 (format "${%s:%s}\n\n" index question))
               (-zip (number-sequence 0 (length questions)) questions)))
             "$0\n\n"
             "Have fun,\n\nAndrea\n")))
      (yas-define-snippets 'mu4e-compose-mode (list (list "q" snippet "mail-with-question-snippet" nil nil nil nil nil nil))))))

Finally hook up the redefinition of the snippet to the mode hook, in this case anytime I am replying an email:

(add-hook 'mu4e-compose-mode-hook 'my/update-q-snippet)

And that is it! Now if you reply an email and invoke the snippet expansion you get the right number of questions to fill in.

Conclusion

Well time to try yourself. If you are a mu4e user this will likely help you too with handling your questions. Just load the elisp code and try to expand the snippet in your next email reply!

Happy emailing!

P.S: you need dash.el, s.el and mu4e to run the snippets of elisp above.

Where parallels cross