I want to write a yasnippet template that will allow me to add a license header to the script buffer in Emacs. For example, this but improved a bit:
- The header should include data for each user, such as the date name and email address of the copyright holder, which can be obtained using the built-in elisp extension from yasnippet.
- The header should be commented out by the syntax depending on the programming mode in which the file is located. There is already the essence of the fragment that does it all . This basically means embedding
(comment-region (point-min) (point)) at the end of your fragment. - Now I want to change the comment style on the field . See the emacs documentation for the
comment-style variable, or if you want to see what a window-style comment looks like, just call Mx comment-box in the active region: it calls comment-region with the correct parameters.
The first approach for this is to set the style by changing the end of the previous snippet to:
(let ((comment-style 'box)) (comment-region (point-min) (point)))
Unfortunately, the padding is screwed, and my box is not rectangular . If I start with a snippet:
Copyright (c) ${1:`(nth 5 (decode-time))`} All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted` (let ((comment-style 'box)) (comment-region (point-min) (point)))`
Extending this snippet "breaks the window" (I am debugging this snippet with ocaml comment syntax, not that it matters):
(**************************************************************) (* Copyright (c) 2010 *) (* All rights reserved. *) (* *) (* Redistribution and use in source and binary forms, with or *) (* without modification, are permitted *) (**************************************************************)
- At first I thought that the second line was indented based on the size of the embedded code with the preliminary extension, but in this case it should make the final
*) this line too soon 25, not 4. - If he is dismissed on the basis of the lack of text present at the point of implementation, the final
*) must arrive at 4 spaces too late, and not too soon. - Finally, I don’t understand what happens to the last line, in which there is no built-in code extension. Usually I have no problem getting the square comment field from the paragraph with the short last line (either using the
comment-box or the elisp function in the first comment block of this question.
I tried to make a comment after expanding the fragment in order to avoid the side effect by adding it to yas/after-exit-snippet-hook , replacing the Last function of the fragment above:
(add-hook 'yas/after-exit-snippet-hook (let ((comment-style 'box)) (comment-region (point-min) (point))) nil t)
But it did not help. Even if that were the case, it would leave me with an extension that commented on all the fragments that I would like to use in this buffer, which I certainly do not want.
I should also add that I tried to set yas/indent-line to fixed by adding
# expand-env: ((yas/indent-line 'fixed))
at the beginning of my fragment, but that didn’t change anything. Any ideas on how to get a rectangle
Edit: We have a very good answer, as well as the proposed fix (kudos and thanks, Seiji!), But the question remains about how to adapt it to the case where you would need to reuse the field, for example, reusing $1 in:
Copyright (c) ${1:`(nth 5 (decode-time))`} All rights reserved. Redistribution and use in $1, in source and binary forms `(let ((comment-style 'box)) (comment-region (point-min) (point-at-eol 0)))`
In this case, the template mechanism copies the value (of variable length) obtained for the field $1 , namely 2011 , to the last line when expanding the template (after the indent), indicating the comment line of 2 characters is too wide. It is difficult to predict when writing a pattern that 4 characters should be deleted on this line. Perhaps the reuse of fields and the right margins are too many to require at the same time. Does anyone see a way to do this though?