emacs/lisp/man-plus.el

;;; man-plus.el --- Fix the ugly emacs manpages

;;; Commentary:
;; Loosely based on neovim's `man.vim' functionality.
;;
;; Feature goals:
;; - MANWIDTH based on size of new window
;; - Lots of different colors for headings, options,
;;   sh snippets, etc

;;; Code:

(defvar man-plus-highlights
  (let* (
	 (manReference "[^()[:space:]]\\\\+(\\\\%([0-9][a-z]*\\\\|[nlpox]\\\\))")
	 (manSectionHeading "^\\\\S.*$")
	 (manHeader "^\\\\%1l.*$")
	 (manSubHeading "^ \\\\{3\\\\}\\\\S.*$")
	 (manOptionDesc "^\\\\s\\\\+\\\\%(+\\\\|-\\\\)\\\\S\\\\+"))
    `(
	 (,manReference . 'link)
	 (,manSectionHeading . 'outline-1)
	 (,manHeader . 'org-document-title)
	 (,manSubHeading . 'font-lock-function-name-face)
	 (,manOptionDesc . 'font-lock-constant-face)
      )))

(defface manHeader
  '((t (:inherit org-document-title)))
  "Top-level heading for Man pages..."
  :group 'man)
(defface manSectionHeading
  '((t (:inherit outline-1)))
  "Man section titles..."
  :group 'man)
(defface manOptionDesc
  '((t (:inherit font-lock-constant-face)))
  "Man option descriptions..."
  :group 'man)
(defface manReference
  '((t (:inherit link)))
  "Man references to other pages..."
  :group 'man)
(defface manSubHeading
  '((t (:inherit font-lock-function-name-face)))
  "Manual sub headings..."
  :group 'man)

(defun man-plus-setall ()
  "Do all of the things that Man wants. To be run as `Man-mode-hook'."
  (interactive)
  (setq font-lock-defaults '(man-plus-highlights)))

(add-hook 'man-common-hook #'man-plus-setall)
(add-hook 'man-common-hook #'turn-off-line-numbers)

(define-derived-mode man-plus-mode man-common "ManPlus"
  "Custom child mode for man mode, structured like the `nvim' builtin plugin."
  (buffer-disable-undo)
  (auto-fill-mode -1)
  (man-plus-setall)
  (turn-off-line-numbers))

(provide 'man-plus)
;;; man-plus.el ends here