+;;; compact-docstrings.el --- Shrink blank lines in docstrings and doc comments
+
+;; Copyright (C) 2016 Free Software Foundation, Inc.
+
+;; Author: Clément Pit-Claudel <clement.pitclaudel@live.com>
+;; Maintainer: Clément Pit-Claudel <clement.pitclaudel@live.com>
+;; URL: https://github.com/cpitclaudel/compact-docstrings
+;; Package-Version: 0.1
+;; Keywords: convenience, faces, lisp, maint, c
+
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; Shrink blank lines in docstrings and doc comments
+;;
+;; Enable locally with `compact-docstrings-mode':
+;; (add-hook 'some-mode-hook #'compact-docstrings-mode)
+;;
+;; Enable globally (in all programming modes) with
+;; (add-hook 'after-init-hook #'global-compact-docstrings--mode)
+
+;;; Code:
+
+(defgroup compact-docstrings nil
+ "Shrink empty lines in docstrings and doc comments."
+ :group 'faces)
+
+(defface compact-docstrings-face
+ '((t :height 0.5))
+ "Face applied to blank lines in docstrings."
+ :group 'compact-docstrings)
+
+(defcustom compact-docstrings-only-doc-blocks t
+ "When nil, also shrink blank lines in regular strings and comments."
+ :group 'compact-docstrings
+ :type 'boolean)
+
+(defun compact-docstrings--matcher (bound)
+ "Find blank line in docstring, looking in point .. BOUND."
+ (let ((found nil))
+ (while (and (not found) (re-search-forward "^\\s-*\n" bound t))
+ (let ((syntax (syntax-ppss)))
+ (when (and (or (nth 3 syntax) ;; In string
+ (nth 4 syntax)) ;; In comment
+ (or (not compact-docstrings-only-doc-blocks)
+ (let ((face (get-text-property (point) 'face)))
+ (or (eq face 'font-lock-doc-face)
+ (and (listp face) (memq 'font-lock-doc-face face))))))
+ (setq found t))))
+ found))
+
+(defconst compact-docstrings--keywords
+ '((compact-docstrings--matcher 0 'compact-docstrings-face prepend)) 'append)
+
+;;;###autoload
+(define-minor-mode compact-docstrings-mode
+ "Shrink empty lines in docstrings and doc comments."
+ :lighter " compact"
+ (if compact-docstrings-mode
+ (font-lock-add-keywords nil compact-docstrings--keywords 'append)
+ (font-lock-remove-keywords nil compact-docstrings--keywords))
+ (if (fboundp #'font-lock-flush)
+ (font-lock-flush)
+ (with-no-warnings (font-lock-fontify-buffer))))
+
+(defun compact-docstrings--mode-on ()
+ "Turn on `compact-docstrings-mode', if appropriate."
+ (when (derived-mode-p major-mode #'prog-mode)
+ (compact-docstrings-mode)))
+
+;;;###autoload
+(defalias 'shrink-docstrings #'compact-docstrings--mode-on)
+
+;;;###autoload
+(define-globalized-minor-mode global-compact-docstrings-mode compact-docstrings-mode
+ compact-docstrings--mode-on
+ :init-value nil)
+
+(provide 'compact-docstrings)
+;;; compact-docstrings.el ends here