markdown-mode.el

   1 ;;; markdown-mode.el --- Major mode to edit Markdown files in Emacs
   2 ;;
   3 ;; Author: Jason Blevins <jrblevin@sdf.lonestar.org>
   4 ;; Maintainer: Jason Blevins <jrblevin@sdf.lonestar.org>
   5 ;; Created: May 24, 2007
   6 ;; $Id: markdown-mode.el,v 1.3 2007/06/05 03:29:43 jrblevin Exp $
   7 ;; Keywords: Markdown major mode
   8 ;;
   9 ;; Copyright (C) 2007 Jason Blevins
  10 ;;
  11 ;; This program is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15 ;;
  16 ;; This program is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20 ;;
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with this program; if not, write to the Free Software
  23 ;; Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  24 ;;
  25 ;; Supported Emacsen:
  26 ;; ==================
  27 ;; This mode has only been tested on Emacs 22.0.  Please let me know
  28 ;; if there are problems on other versions.
  29 ;;
  30 ;; Installation:
  31 ;; =============
  32 ;; Add the following lines to your .emacs file to associate
  33 ;; markdown-mode with .mdml files.   There doesn't seem to be
  34 ;; a consensus on an official file extension so you can change
  35 ;; this to .text, .md, .mdt, or whatever you call your markdown
  36 ;; files.
  37 ;;
  38 ;;   (autoload 'markdown-mode "markdown-mode.el"
  39 ;;      "Major mode for editing Markdown files" t)
  40 ;;   (setq auto-mode-alist
  41 ;;     (cons '("\\.mdml$" . markdown-mode) auto-mode-alist))
  42 ;;
  43 ;; Make sure to place this file somewhere in the load-path.
  44 ;;
  45 ;; Description:
  46 ;; ============
  47 ;; This mode provides basic syntax highlighting, element insertion
  48 ;; commands, and preview commands for Markdown files.  The latest version
  49 ;; should always be available from
  50 ;; http://jrblevin.freeshell.org/software/markdown-mode.
  51 ;;
  52 ;; TODO:
  53 ;; =====
  54 ;; * Recognize inline HTML.
  55 ;; * Bold at the beginning of a line is mistaken to be a list item.
  56 ;; * itex font lock support:
  57 ;;   + Equation references: (eq:reference) or \eqref{reference}.
  58 ;;   + Separate font locking for \label{} elements in side \[ \] equations.
  59
  60 (defconst markdown-mode-version "$Revision: 1.3 $")
  61
  62 ;; A hook for users to run their own code when the mode is loaded.
  63 (defvar markdown-mode-hook nil)
  64
  65
  66 ;;; Customizable variables ====================================================
  67
  68 (defgroup markdown nil
  69   "Markdown mode."
  70   :prefix "markdown-"
  71   :group 'languages)
  72
  73 (defcustom markdown-command "markdown"
  74   "Command to run markdown."
  75   :group 'markdown
  76   :type 'string)
  77
  78 (defcustom markdown-hr-length 5
  79   "Length of horizonal rules."
  80   :group 'markdown
  81   :type 'integer)
  82
  83 (defcustom markdown-bold-underscore nil
  84   "Use two underscores for bold instead of two asterisks."
  85   :group 'markdown
  86   :type 'boolean)
  87
  88 (defcustom markdown-italic-underscore nil
  89   "Use underscores for italic instead of asterisks."
  90   :group 'markdown
  91   :type 'boolean)
  92
  93
  94 ;;; Regular expressions =======================================================
  95
  96 ;; Links
  97 (defconst regex-link-inline "\\(!?\\[.+?\\]\\)\\((.*)\\)"
  98   "Regular expression for a [text](file) or an image link ![text](file)")
  99 (defconst regex-link-reference "\\(!?\\[.+?\\]\\)[ ]?\\(\\[.*?\\]\\)"
 100   "Regular expression for a reference link [text][id]")
 101 (defconst regex-reference-definition
 102   "^\s*\\(\\[.+?\\]\\):\s*\\([^\s\n]+\\).*$"
 103   "Regular expression for a link definition [id]: ...")
 104
 105
 106 ;;; Font lock =================================================================
 107
 108 (defconst markdown-mode-font-lock-keywords
 109   (list
 110    ;; Latex/itex
 111 ;   (cons "\\\\\\[[^$]+\\\\\\]" 'font-lock-string-face)
 112 ;   (cons "\\$\\$[^$]+\\$\\$" 'font-lock-string-face)
 113 ;   (cons "\\$[^$]+\\$" 'font-lock-string-face)
 114    ;; Headers and (Horizontal Rules)
 115    (cons ".*\n?===*" 'font-lock-function-name-face)     ; === headers
 116    (cons ".*\n?---*" 'font-lock-function-name-face)     ; --- headers
 117    (cons "^#+ .*$" 'font-lock-function-name-face)       ; ### Headers
 118    (cons "^\\*[\\*\s]*$" 'font-lock-function-name-face) ; * * * style HRs
 119    (cons "^-[-\s]*$" 'font-lock-function-name-face)     ; - - - style HRs
 120    ;; Blockquotes
 121    (cons "^>.*$" 'font-lock-comment-face)            ; > blockquote
 122    ;; Bold
 123    (cons "[^\\]?\\*\\*.+?\\*\\*" 'font-lock-type-face)     ; **bold**
 124    (cons "[^\\]?__.+?__" 'font-lock-type-face)             ; __bold__
 125    ;; Italic
 126    (cons "[^\\]?\\*.+?\\*" 'font-lock-variable-name-face)  ; *italic*
 127    (cons "[^\\]?_.+?_" 'font-lock-variable-name-face)      ; _italic_
 128    ;; Lists
 129    (cons "^[0-9]+\\." 'font-lock-variable-name-face) ; Numbered list
 130    (cons "^\\*" 'font-lock-variable-name-face)       ; Level 1 (no indent)
 131    (cons "^\\+" 'font-lock-variable-name-face)       ; Level 1 (no indent)
 132    (cons "^\\-" 'font-lock-variable-name-face)       ; Level 1 (no indent)
 133    (cons "^  [ ]*\\*" 'font-lock-variable-name-face) ; Level 2 (two or more)
 134    (cons "^  [ ]*\\+" 'font-lock-variable-name-face) ; Level 2 (two or more)
 135    (cons "^  [ ]*\\-" 'font-lock-variable-name-face) ; Level 2 (two or more)
 136    ;; Links
 137    (cons regex-link-inline '(1 'font-lock-string-face t))
 138    (cons regex-link-inline '(2 'font-lock-constant-face t))
 139    (cons regex-link-reference '(1 'font-lock-string-face t))
 140    (cons regex-link-reference '(2 'font-lock-comment-face t))
 141    (cons regex-reference-definition '(1 'font-lock-comment-face t))
 142    (cons regex-reference-definition '(2 'font-lock-constant-face t))
 143    ;; Wiki links
 144 ;   (cons "\\[\\[\\w+\\]\\]" 'font-lock-string-face)  ; Standard wiki link
 145    (cons "\\[\\[.+\\]\\]" 'font-lock-string-face)
 146    ;; Code
 147    (cons "``.+?``" 'font-lock-constant-face)         ; ``inline code``
 148    (cons "`.+?`" 'font-lock-constant-face)           ; `inline code`
 149    (cons "^    .*$" 'font-lock-constant-face)        ;     code block
 150    )
 151   "Syntax highlighting for Markdown files.")
 152
 153
 154 ;;; Element Insertion ==========================================================
 155
 156 (defun wrap-or-insert (s1 s2)
 157  "Insert the strings s1 and s2 around the current region or just insert them
 158 if there is no region selected."
 159  (if (and transient-mark-mode mark-active)
 160      (let ((a (region-beginning)) (b (region-end)))
 161        (kill-region a b)
 162        (insert s1)
 163        (yank)
 164        (insert s2))
 165    (insert s1 s2)))
 166
 167 (defun markdown-insert-hr ()
 168   "Insert a horizonal rule."
 169   (interactive)
 170   (let (hr)
 171     (dotimes (count (- markdown-hr-length 1) hr)        ; Count to n - 1
 172       (setq hr (concat "* " hr)))                       ; Build HR string
 173     (setq hr (concat hr "*\n"))                         ; Add the n-th *
 174     (insert hr)))
 175
 176 (defun markdown-insert-bold ()
 177   "Make the active region bold or insert an empty bold word."
 178   (interactive)
 179   (if markdown-bold-underscore
 180       (wrap-or-insert "__" "__")
 181     (wrap-or-insert "**" "**"))
 182   (backward-char 2))
 183
 184 (defun markdown-insert-italic ()
 185   "Make the active region italic or insert an empty italic word."
 186   (interactive)
 187   (if markdown-italic-underscore
 188       (wrap-or-insert "_" "_")
 189     (wrap-or-insert "*" "*"))
 190   (backward-char 1))
 191
 192 (defun markdown-insert-code ()
 193   "Format the active region as inline code or insert an empty inline code
 194 fragment."
 195   (interactive)
 196   (wrap-or-insert "`" "`")
 197   (backward-char 1))
 198
 199 (defun markdown-insert-link ()
 200   "Creates an empty link of the form []().  If there is an active region,
 201 this text will be used for the link text."
 202   (interactive)
 203   (wrap-or-insert "[" "]")
 204   (insert "()")
 205   (backward-char 1))
 206
 207 (defun markdown-insert-image ()
 208   "Creates an empty image of the form ![]().  If there is an active region,
 209 this text will be used for the alternate text for the image."
 210   (interactive)
 211   (wrap-or-insert "![" "]")
 212   (insert "()")
 213   (backward-char 1))
 214
 215 (defun markdown-insert-header-1 ()
 216   "Creates a level 1 header"
 217   (interactive)
 218   (markdown-insert-header 1))
 219
 220 (defun markdown-insert-header-2 ()
 221   "Creates a level 2 header"
 222   (interactive)
 223   (markdown-insert-header 2))
 224
 225 (defun markdown-insert-header-3 ()
 226   "Creates a level 3 header"
 227   (interactive)
 228   (markdown-insert-header 3))
 229
 230 (defun markdown-insert-header-4 ()
 231   "Creates a level 4 header"
 232   (interactive)
 233   (markdown-insert-header 4))
 234
 235 (defun markdown-insert-header-5 ()
 236   "Creates a level 5 header"
 237   (interactive)
 238   (markdown-insert-header 5))
 239
 240 (defun markdown-insert-header (n)
 241   "Creates a level n header.  If there is an active region, it is used as the
 242 header text."
 243   (interactive "p")
 244   (unless n                             ; Test to see if n is defined
 245     (setq n 1))                         ; Default to level 1 header
 246   (let (hdr)
 247     (dotimes (count n hdr)
 248       (setq hdr (concat "#" hdr)))      ; Build a ### header string
 249     (setq hdrl (concat hdr " "))
 250     (setq hdrr (concat " " hdr))
 251     (wrap-or-insert hdrl hdrr))
 252   (backward-char (+ 1 n)))
 253
 254 (defun markdown-insert-title ()
 255   "Use the active region to create an \"equals\" style title or insert
 256 a blank title and move the cursor to the required position in order to
 257 insert a title."
 258   (interactive)
 259   (if (and transient-mark-mode mark-active)
 260       (let ((a (region-beginning))
 261             (b (region-end))
 262             (len 0)
 263             (hdr))
 264         (setq len (- b a))
 265         (dotimes (count len hdr)
 266           (setq hdr (concat "=" hdr)))  ; Build a === title underline
 267         (end-of-line)
 268         (insert "\n" hdr "\n"))
 269     (insert "\n==========\n")
 270     (backward-char 12)))
 271
 272 (defun markdown-insert-section ()
 273   "Use the active region to create a dashed style section or insert
 274 a blank section and move the cursor to the required position in order to
 275 insert a section."
 276   (interactive)
 277   (if (and transient-mark-mode mark-active)
 278       (let ((a (region-beginning))
 279             (b (region-end))
 280             (len 0)
 281             (hdr))
 282         (setq len (- b a))
 283         (dotimes (count len hdr)
 284           (setq hdr (concat "-" hdr)))  ; Build a --- section underline
 285         (end-of-line)
 286         (insert "\n" hdr "\n"))
 287     (insert "\n----------\n")
 288     (backward-char 12)))
 289
 290 (defun markdown-insert-blockquote ()
 291   "Start a blank blockquote section unless there is an active region, in
 292 which case it is turned into a blockquote region."
 293   (interactive)
 294   (if (and (boundp 'transient-mark-mode) transient-mark-mode mark-active)
 295       (blockquote-region)
 296     (insert "> ")))
 297
 298
 299 ;;; Keymap ====================================================================
 300
 301 (defvar markdown-mode-map
 302   (let ((markdown-mode-map (make-keymap)))
 303     ;; Element insertion
 304     (define-key markdown-mode-map "\C-c\C-al" 'markdown-insert-link)
 305     (define-key markdown-mode-map "\C-c\C-ii" 'markdown-insert-image)
 306     (define-key markdown-mode-map "\C-c\C-t1" 'markdown-insert-header-1)
 307     (define-key markdown-mode-map "\C-c\C-t2" 'markdown-insert-header-2)
 308     (define-key markdown-mode-map "\C-c\C-t3" 'markdown-insert-header-3)
 309     (define-key markdown-mode-map "\C-c\C-t4" 'markdown-insert-header-4)
 310     (define-key markdown-mode-map "\C-c\C-t5" 'markdown-insert-header-5)
 311     (define-key markdown-mode-map "\C-c\C-pb" 'markdown-insert-bold)
 312     (define-key markdown-mode-map "\C-c\C-ss" 'markdown-insert-bold)
 313     (define-key markdown-mode-map "\C-c\C-pi" 'markdown-insert-italic)
 314     (define-key markdown-mode-map "\C-c\C-se" 'markdown-insert-italic)
 315     (define-key markdown-mode-map "\C-c\C-pf" 'markdown-insert-code)
 316     (define-key markdown-mode-map "\C-c\C-sc" 'markdown-insert-code)
 317     (define-key markdown-mode-map "\C-c\C-sb" 'markdown-insert-blockquote)
 318     (define-key markdown-mode-map "\C-c-" 'markdown-insert-hr)
 319     (define-key markdown-mode-map "\C-c\C-tt" 'markdown-insert-title)
 320     (define-key markdown-mode-map "\C-c\C-ts" 'markdown-insert-section)
 321     ;; Markdown functions
 322     (define-key markdown-mode-map "\C-c\C-cm" 'markdown)
 323     (define-key markdown-mode-map "\C-c\C-cp" 'markdown-preview)
 324     markdown-mode-map)
 325   "Keymap for Markdown major mode")
 326
 327
 328 ;;; Markdown ==================================================================
 329
 330 (defun markdown ()
 331   "Run markdown on the current buffer and preview the output in another buffer."
 332   (interactive)
 333     (if (and (boundp 'transient-mark-mode) transient-mark-mode mark-active)
 334         (shell-command-on-region region-beginning region-end markdown-command
 335                                  "*markdown-output*" nil)
 336       (shell-command-on-region (point-min) (point-max) markdown-command
 337                                "*markdown-output*" nil)))
 338
 339 (defun markdown-preview ()
 340   "Run markdown on the current buffer and preview the output in a browser."
 341   (interactive)
 342   (markdown)
 343   (browse-url-of-buffer "*markdown-output*"))
 344
 345
 346 ;;; Utilities =================================================================
 347
 348 (defun markdown-show-version ()
 349   "Show the version number in the minibuffer."
 350   (interactive)
 351   (message "markdown-mode, version %s" markdown-mode-version))
 352
 353 (defun blockquote-region ()
 354   "Blockquote an entire region."
 355   (interactive)
 356   (if (and (boundp 'transient-mark-mode) transient-mark-mode mark-active)
 357       (replace-regexp "^" "> ")))
 358
 359
 360 ;; Mode definition  ===========================================================
 361
 362 (define-derived-mode markdown-mode fundamental-mode "Markdown"
 363   "Major mode for editing Markdown files."
 364   ;; Font lock.
 365   (set (make-local-variable 'font-lock-defaults)
 366        '(markdown-mode-font-lock-keywords))
 367   (set (make-local-variable 'font-lock-multiline) t))
 368
 369 ;(add-to-list 'auto-mode-alist '("\\.mdml$" . markdown-mode))
 370
 371 (provide 'markdown-mode)
 372
 373 ;;; Change log
 374 ;; 2007-05-29 Jason Blevins <jrblevin@sdf.lonestar.org>
 375 ;;   * Added support for equals and dash style headings.
 376 ;;   * Added markdown-show-version.
 377 ;;   * Ability to preview markdown output in a buffer (markdown) or
 378 ;;     in a browser (markdown-preview).  Markdown command is customizable.
 379 ;;   * Made HR length customizable through markdown-hr-length.
 380 ;;   * Made bold and italic style customizable through markdown-bold-underscore
 381 ;;     and markdown-italic-underscore.
 382 ;;   * Made keybindings more like those of html-helper-mode.
 383 ;;   * Added image insertion (markdown-insert-image).
 384 ;;   * Font lock for code fragments with double backticks.
 385 ;;   * Added blockquote-region function and insert-blockquote keybinding.
 386 ;;   * Don't highlight escaped literals such as \* or \_.
 387 ;;   * Added header insertion commands for H1-H5 (markdown-insert-header-n).
 388 ;;
 389 ;; 2007-05-25 Jason Blevins <jrblevin@sdf.lonestar.org>
 390 ;;   * Added element insertion commands and keys for links, horizontal rules,
 391 ;;     headers, inline code, and bold and italic text.
 392 ;;   * Revision 1.2.
 393 ;;
 394 ;; 2007-05-24 Jason Blevins <jrblevin@sdf.lonestar.org>
 395 ;;   * Initial revision.
 396 ;;   * Basic syntax highlighting support.
 397 ;;   * Revision 1.1.
 398
 399 ;;; markdown-mode.el ends here