clojure-fill-paragraph acts incorrectly in variable docstring

[raxod502]

Expected behavior

Given the following text in clojure-mode, with point represented by |:

(def my-example-variable
  "It has a very long docstring. So long, in fact, that it wraps onto multiple lines! This is to demonstrate what happens when the docstring wraps over three lines.|"
  nil)

Pressing M-q should yield the following:

(def my-example-variable
  "It has a very long docstring. So long, in fact, that it wraps onto
  multiple lines! This is to demonstrate what happens when the
  docstring wraps over three lines.|"
  nil)

Actual behavior

The initial value of the variable is wrapped onto the same line as the docstring:

(def my-example-variable
  "It has a very long docstring. So long, in fact, that it wraps onto
  multiple lines! This is to demonstrate what happens when the
  docstring wraps over three lines."  nil)

Steps to reproduce the problem

Run emacs -Q, install clojure-mode, and open a Clojure file. Then see the "Expected behavior" section.

Environment & Version information

clojure-mode version information

clojure-mode (version 5.7.0-snapshot)

I am running revision 197298e of clojure-mode using straight.el.

Emacs version

GNU Emacs 25.2.1 (x86_64-apple-darwin13.4.0, NS appkit-1265.21 Version 10.9.5 (Build 13F1911))

Installed by brew cask install emacs, running in the terminal.

Operating system

                -/+:.           raxod502@[redacted]
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     `:+oo+/:-..-:/+o+/-        GPU: Intel Iris Pro, NVIDIA GeForce GT 750M
                                Memory: 4322MiB / 16384MiB

Commentary

Filling works correctly for functions. I presume that one of regexes must be tweaked in clojure-fill-paragraph, as the current ones apparently only recognize a vector as terminating the docstring.

(defun clojure-fill-paragraph (&optional justify)
  "Like `fill-paragraph', but can handle Clojure docstrings.

If JUSTIFY is non-nil, justify as well as fill the paragraph."
  (if (clojure-in-docstring-p)
      (let ((paragraph-start
             (concat paragraph-start
                     "\\|\\s-*\\([(:\"[]\\|~@\\|`(\\|#'(\\)"))
            (paragraph-separate
             (concat paragraph-separate "\\|\\s-*\".*[,\\.]$"))
            (fill-column (or clojure-docstring-fill-column fill-column))
            (fill-prefix (clojure-docstring-fill-prefix)))
        (fill-paragraph justify))
    (let ((paragraph-start (concat paragraph-start
                                   "\\|\\s-*\\([(:\"[]\\|`(\\|#'(\\)"))
          (paragraph-separate
           (concat paragraph-separate "\\|\\s-*\".*[,\\.[]$")))
      (or (fill-comment-paragraph justify)
          (fill-paragraph justify))
      ;; Always return `t'
      t)))

[raxod502]

@bbatsov Thanks, it works now. However, I prefer to redefine defonce so that it takes a docstring, and my example is broken again when I replace def with defonce:

(defonce my-example-variable
  "It has a very long docstring. So long, in fact, that it wraps onto multiple lines! This is to demonstrate what happens when the docstring wraps over three lines.|"
  nil)

This seems reasonable since I'm extending Clojure in a nonstandard way. However, it is possible for me to customize clojure-mode so that it recognizes defonce as taking a docstring?

[vspinu]

It might make sense to apply that "fill" fix to all strings, not just doc-strings.