Description
Hey,
Consider following code:
{-# LANGUAGE SomeExtension #-}
module App where
-- one line comment
main :: IO ()
main = undefined
When you call shm/comment while on line -- one line comment - instead of uncommenting this one-line comment, it will 'uncomment' {-# LANGUAGE SomeExtension -#} into # LANGUAGE SomeExtension #.
What expected - uncomment one-liner via comment-dwim or do nothing. But anyway, don't uncomment pragma.
Some additional information.
Looks like shm/comment uses shm-in-comment to decide either it's in comment or not. And the latter function handles pragmas properly. But shm/comment uses (search-backward-regexp "{-" nil nil 1), so in situation with one liner it finds {- from the pragma - and uncomments it. I think instead of searching for {- it should search for {-[^#]. But it would just throw error in case of one-line comment. Probably it's better to handle them.
What I am using right now as a workaround is following function
(defun my-shm/comment ()
"Comment the current node, or if there is none, or some error,
fall back to `comment-dwim'. If the region is active, uses
`comment-dwim'."
(interactive)
(if (region-active-p)
(call-interactively 'comment-dwim)
(let ((is-multiline-comment nil)
(current (shm-current-node)))
(cond
((shm-in-comment)
(save-excursion
(unless (looking-at "[-{]-[^#]")
(search-backward-regexp "[-{]-[^#]" nil nil 1))
(when (looking-at "{-[^#]")
(setq is-multiline-comment t))
(delete-region (point) (+ 2 (point)))
(if is-multiline-comment
(search-forward-regexp "-}" nil nil 1)
(search-forward-regexp "\n" nil nil 1))
(if (string-equal (match-string 0) "-}")
(delete-region (- (point) 2) (point))
(delete-region (- (point) 0) (point)))))
(current
(save-excursion
(goto-char (shm-node-start current))
(insert "{-")
(goto-char (shm-node-end current))
(insert "-}")
(font-lock-fontify-region (shm-node-start current)
(shm-node-end current))))
(t (call-interactively 'comment-dwim))))))