markdown-mode.el

   1 ;;; markdown-mode.el --- Major mode to edit Markdown files in Emacs
   2
   3 ;; Copyright (C) 2007, 2008, 2009, 2010, 2011 Jason R. Blevins
   4 ;; Copyright (C) 2007, 2009 Edward O'Connor <ted@oconnor.cx>
   5 ;; Copyright (C) 2007 Conal Elliott <conal@conal.net>
   6 ;; Copyright (C) 2008 Greg Bognar <greg_bognar@hms.harvard.edu>
   7 ;; Copyright (C) 2008 Dmitry Dzhus <mail@sphinx.net.ru>
   8 ;; Copyright (C) 2008 Bryan Kyle <bryan.kyle@gmail.com>
   9 ;; Copyright (C) 2008 Ben Voui <intrigeri@boum.org>
  10 ;; Copyright (C) 2009 Ankit Solanki <ankit.solanki@gmail.com>
  11 ;; Copyright (C) 2009 Hilko Bengen <bengen@debian.org>
  12 ;; Copyright (C) 2009 Peter Williams <pezra@barelyenough.org>
  13 ;; Copyright (C) 2010 George Ogata <george.ogata@gmail.com>
  14 ;; Copyright (C) 2011 Eric Merritt <ericbmerritt@gmail.com>
  15 ;; Copyright (C) 2011 Philippe Ivaldi <pivaldi@sfr.fr>
  16
  17 ;; Version: 1.8-dev
  18 ;; Keywords: Markdown major mode
  19 ;; Author: Jason R. Blevins <jrblevin@sdf.org>
  20 ;; URL: http://jblevins.org/projects/markdown-mode/
  21
  22 ;; This file is not part of GNU Emacs.
  23
  24 ;; This program is free software; you can redistribute it and/or modify
  25 ;; it under the terms of the GNU General Public License as published by
  26 ;; the Free Software Foundation; either version 2, or (at your option)
  27 ;; any later version.
  28
  29 ;; This program is distributed in the hope that it will be useful,
  30 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  31 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  32 ;; GNU General Public License for more details.
  33
  34 ;; You should have received a copy of the GNU General Public License
  35 ;; along with this program; if not, write to the Free Software
  36 ;; Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  37
  38 ;;; Commentary:
  39
  40 ;; markdown-mode is a major mode for editing [Markdown][]-formatted
  41 ;; text files in GNU Emacs.  markdown-mode is free software, licensed
  42 ;; under the GNU GPL.
  43 ;;
  44 ;;  [Markdown]: http://daringfireball.net/projects/markdown/
  45 ;;
  46 ;; The latest stable version is markdown-mode 1.7, released on October 1, 2009:
  47 ;;
  48 ;;    * [markdown-mode.el][]
  49 ;;    * [Screenshot][]
  50 ;;    * [Release notes][]
  51 ;;
  52 ;; markdown-mode is also available in the Debian
  53 ;; [emacs-goodies-el](http://packages.debian.org/emacs-goodies-el)
  54 ;; package (beginning with revision 27.0-1) and the OpenBSD
  55 ;; [textproc/markdown-mode](http://pkgsrc.se/textproc/markdown-mode) package.
  56 ;;
  57 ;;  [markdown-mode.el]: http://jblevins.org/projects/markdown-mode/markdown-mode.el
  58 ;;  [screenshot]: http://jblevins.org/projects/markdown-mode/screenshots/20080604-001.png
  59 ;;  [release notes]: http://jblevins.org/projects/markdown-mode/rev-1-7
  60
  61 ;; The latest development version can be downloaded directly
  62 ;; ([markdown-mode.el][devel.el]) or it can be obtained from the
  63 ;; (browsable and clonable) Git repository at
  64 ;; <http://jblevins.org/git/markdown-mode.git>.  The entire repository,
  65 ;; including the full project history, can be cloned via the Git protocol
  66 ;; by running
  67 ;;
  68 ;;     git clone git://jblevins.org/git/markdown-mode.git
  69 ;;
  70 ;;  [devel.el]: http://jblevins.org/git/markdown-mode.git/plain/markdown-mode.el
  71
  72 ;;; Dependencies:
  73
  74 ;; markdown-mode requires easymenu, a standard package since GNU Emacs
  75 ;; 19 and XEmacs 19, which provides a uniform interface for creating
  76 ;; menus in GNU Emacs and XEmacs.
  77
  78 ;;; Installation:
  79
  80 ;; Make sure to place `markdown-mode.el` somewhere in the load-path and add
  81 ;; the following lines to your `.emacs` file to associate markdown-mode
  82 ;; with `.text` files:
  83 ;;
  84 ;;     (autoload 'markdown-mode "markdown-mode.el"
  85 ;;        "Major mode for editing Markdown files" t)
  86 ;;     (setq auto-mode-alist
  87 ;;        (cons '("\\.text" . markdown-mode) auto-mode-alist))
  88 ;;
  89 ;; There is no consensus on an official file extension so change `.text` to
  90 ;; `.mdwn`, `.md`, `.mdt`, or whatever you call your markdown files.
  91
  92 ;;; Customization:
  93
  94 ;; Although no configuration is *necessary* there are a few things
  95 ;; that can be customized.  The `M-x customize-mode` command
  96 ;; provides an interface to all of the possible customizations:
  97 ;;
  98 ;;   * `markdown-command' - the command used to run Markdown (default:
  99 ;;     `markdown').  This variable may be customized to pass
 100 ;;     command-line options to your Markdown processor of choice, but
 101 ;;     this command must accept input from `stdin`.  If it does not, a
 102 ;;     simple wrapper script can be used to write `stdin` to a file
 103 ;;     and then pass that file to your Markdown interpreter.  Ideally,
 104 ;;     this command will produce an XHTML fragment around which
 105 ;;     markdown-mode will wrap a header and footer (which can be
 106 ;;     further customized).  However, it attempts to detect whether
 107 ;;     the command produces standalone XHTML output (via
 108 ;;     `markdown-xhtml-standalone-regexp'), in which case no header
 109 ;;     and footer content will be added.
 110 ;;
 111 ;;   * `markdown-hr-length' - the length of horizontal rules
 112 ;;     (default: `5').
 113 ;;
 114 ;;   * `markdown-bold-underscore' - set to a non-nil value to use two
 115 ;;     underscores for bold instead of two asterisks (default: `nil').
 116 ;;
 117 ;;   * `markdown-italic-underscore' - set to a non-nil value to use
 118 ;;     underscores for italic instead of asterisks (default: `nil').
 119 ;;
 120 ;;   * `markdown-indent-function' - the function to use for automatic
 121 ;;     indentation (default: `markdown-indent-line').
 122 ;;
 123 ;;   * `markdown-indent-on-enter' - set to a non-nil value to
 124 ;;     automatically indent new lines when the enter key is pressed
 125 ;;     (default: `t')
 126 ;;
 127 ;;   * `markdown-follow-wiki-link-on-enter' - set to a non-nil value
 128 ;;     to automatically open a linked document in a new buffer if the
 129 ;;     cursor is an wiki link
 130 ;;     (default: `t')
 131 ;;
 132 ;;   * `markdown-uri-types' - a list of protocols for URIs that
 133 ;;     `markdown-mode' should highlight.
 134 ;;
 135 ;;   * `markdown-enable-math' - syntax highlighting for
 136 ;;     LaTeX fragments (default: `nil').
 137 ;;
 138 ;;   * `markdown-css-path' - CSS file to link to in XHTML output.
 139 ;;
 140 ;;   * `markdown-xhtml-header-content' - additional content to include
 141 ;;     in the XHTML <head> block.
 142 ;;
 143 ;;  * `markdown-xhtml-standalone-regexp' - a regular expression which
 144 ;;    indicates whether the output of `markdown-command' is standalone
 145 ;;    XHTML (default: `^\\(\<\?xml\\|\<!DOCTYPE\\|\<html\\)`).  If
 146 ;;    this is not matched, we assume this output is a fragment and add
 147 ;;    our own header and footer.
 148 ;;
 149 ;; Additionally, the faces used for syntax highlighting can be modified to
 150 ;; your liking by issuing `M-x customize-group RET markdown-faces`
 151 ;; or by using the "Markdown Faces" link at the bottom of the mode
 152 ;; customization screen.
 153
 154 ;;; Usage:
 155
 156 ;; Keybindings are grouped by prefixes based on their function.  For
 157 ;; example, commands dealing with headers begin with `C-c C-t`.  The
 158 ;; primary commands in each group will are described below.  You can
 159 ;; obtain a list of all keybindings by pressing `C-c C-h`.
 160 ;;
 161 ;;   * Anchors: `C-c C-a`
 162 ;;
 163 ;;     `C-c C-a l` inserts inline links of the form `[text](url)`.  If
 164 ;;     there is an active region, text in the region is used for the
 165 ;;     link text.  `C-c C-a w` acts similarly for wiki links of the
 166 ;;     form `[[WikiLink]]`.
 167 ;;
 168 ;;   * Commands: `C-c C-c`
 169 ;;
 170 ;;     `C-c C-c m` will run Markdown on the current buffer and preview
 171 ;;     the output in another buffer while `C-c C-c p` runs Markdown on
 172 ;;     the current buffer and previews the output in a browser.
 173 ;;     `C-c C-c e` will run Markdown on the current buffer and save
 174 ;;     the result in the file `basename.html`, where `basename` is the
 175 ;;     name of the Markdown file with the extension removed.  **This
 176 ;;     file will be overwritten without notice.**  Press `C-c C-c v`
 177 ;;     to view the exported file in a browser.
 178 ;;
 179 ;;     `C-c C-c c` will check for undefined references.  If there are
 180 ;;     any, a small buffer will open with a list of undefined
 181 ;;     references and the line numbers on which they appear.  In Emacs
 182 ;;     22 and greater, selecting a reference from this list and
 183 ;;     pressing `RET` will insert an empty reference definition at the
 184 ;;     end of the buffer.  Similarly, selecting the line number will
 185 ;;     jump to the corresponding line.
 186 ;;
 187 ;;   * Images: `C-c C-i`
 188 ;;
 189 ;;     `C-c C-i i` inserts an image, using the active region (if any)
 190 ;;     as the alt text.
 191 ;;
 192 ;;   * Physical styles: `C-c C-p`
 193 ;;
 194 ;;     These commands all act on text in the active region, if any,
 195 ;;     and insert empty markup fragments otherwise.  `C-c C-p b` makes
 196 ;;     the selected text bold, `C-c C-p f` formats the region as
 197 ;;     fixed-width text, and `C-c C-p i` is used for italic text.
 198 ;;
 199 ;;   * Logical styles: `C-c C-s`
 200 ;;
 201 ;;     These commands all act on text in the active region, if any,
 202 ;;     and insert empty markup fragments otherwise.  Logical styles
 203 ;;     include blockquote (`C-c C-s b`), preformatted (`C-c C-s p`),
 204 ;;     code (`C-c C-s c`), emphasis (`C-c C-s e`), and strong (`C-c
 205 ;;     C-s s`).
 206 ;;
 207 ;;   * Headers: `C-c C-t`
 208 ;;
 209 ;;     All header commands use text in the active region, if any, as
 210 ;;     the header text.  To insert an atx or hash style level-n
 211 ;;     header, press `C-c C-t n` where n is between 1 and 6.  For a
 212 ;;     top-level setext or underline style header press `C-c C-t t`
 213 ;;     (mnemonic: title) and for a second-level underline-style header
 214 ;;     press `C-c C-t s` (mnemonic: section).
 215 ;;
 216 ;;   * Other commands
 217 ;;
 218 ;;     `C-c -` inserts a horizontal rule.
 219 ;;
 220 ;; Many of the commands described above behave differently depending on
 221 ;; whether Transient Mark mode is enabled or not.  When it makes sense,
 222 ;; if Transient Mark mode is on and a region is active, the command
 223 ;; applies to the text in the region (e.g., `C-c C-p b` makes the region
 224 ;; bold).  For users who prefer to work outside of Transient Mark mode,
 225 ;; in Emacs 22 it can be enabled temporarily by pressing `C-SPC C-SPC`.
 226 ;;
 227 ;; When applicable, commands that specifically act on the region even
 228 ;; outside of Transient Mark mode have the same keybinding as the with
 229 ;; the exception of an additional `C-` prefix.  For example,
 230 ;; `markdown-insert-blockquote' is bound to `C-c C-s b` and only acts on
 231 ;; the region in Transient Mark mode while `markdown-blockquote-region'
 232 ;; is bound to `C-c C-s C-b` and always applies to the region (when
 233 ;; nonempty).
 234 ;;
 235 ;; markdown-mode supports outline-minor-mode as well as org-mode-style
 236 ;; visibility cycling for atx- or hash-style headers.  There are two
 237 ;; types of visibility cycling: Pressing `S-TAB` cycles globally between
 238 ;; the table of contents view (headers only), outline view (top-level
 239 ;; headers only), and the full document view.  Pressing `TAB` while the
 240 ;; point is at a header will cycle through levels of visibility for the
 241 ;; subtree: completely folded, visible children, and fully visible.
 242 ;; Note that mixing hash and underline style headers will give undesired
 243 ;; results.
 244
 245 ;;; Extensions:
 246
 247 ;; Besides supporting the basic Markdown syntax, markdown-mode also
 248 ;; includes syntax highlighting for `[[Wiki Links]]` by default. Wiki
 249 ;; links may be followed automatically by hitting the enter key when
 250 ;; your curser is on a wiki link or by hitting `C-c C-f`. The
 251 ;; autofollowing on enter key may be controlled with the
 252 ;; `markdown-follow-wiki-link-on-enter' customization.  Use `M-p` and
 253 ;; `M-n` to quickly jump to the previous and next wiki links,
 254 ;; respectively.
 255 ;;
 256 ;; [SmartyPants][] support is possible by customizing `markdown-command'.
 257 ;; If you install `SmartyPants.pl` at, say, `/usr/local/bin/smartypants`,
 258 ;; then you can set `markdown-command' to `"markdown | smartypants"`.
 259 ;; You can do this either by using `M-x customize-group markdown`
 260 ;; or by placing the following in your `.emacs` file:
 261 ;;
 262 ;;     (defun markdown-custom ()
 263 ;;       "markdown-mode-hook"
 264 ;;       (setq markdown-command "markdown | smartypants"))
 265 ;;     (add-hook 'markdown-mode-hook '(lambda() (markdown-custom)))
 266 ;;
 267 ;; [SmartyPants]: http://daringfireball.net/projects/smartypants/
 268 ;;
 269 ;; Experimental syntax highlighting for mathematical expressions written
 270 ;; in LaTeX (only expressions denoted by `$..$`, `$$..$$`, or `\[..\]`)
 271 ;; can be enabled by setting `markdown-enable-math' to a non-nil value,
 272 ;; either via customize or by placing `(setq markdown-enable-itex t)`
 273 ;; in `.emacs`, and restarting Emacs.
 274 ;;
 275 ;; A [GitHub Flavored Markdown](http://github.github.com/github-flavored-markdown/)
 276 ;; mode, `gfm-mode', is also available.  The GitHub implementation of
 277 ;; differs slightly from standard Markdown.  Most importantly, newlines are
 278 ;; significant and trigger hard line breaks.  As such, `gfm-mode' turns off
 279 ;; `auto-fill-mode' and turns on `longlines-mode'.
 280
 281 ;;; Acknowledgments:
 282
 283 ;; markdown-mode has benefited greatly from the efforts of the
 284 ;; following people:
 285 ;;
 286 ;;   * Cyril Brulebois <cyril.brulebois@enst-bretagne.fr> for Debian packaging.
 287 ;;   * Conal Elliott <conal@conal.net> for a font-lock regexp patch.
 288 ;;   * Edward O'Connor <hober0@gmail.com> for a font-lock regexp fix and
 289 ;;     GitHub Flavored Markdown mode (`gfm-mode').
 290 ;;   * Greg Bognar <greg_bognar@hms.harvard.edu> for menus and running
 291 ;;     `markdown' with an active region.
 292 ;;   * Daniel Burrows <dburrows@debian.org> for filing Debian bug #456592.
 293 ;;   * Peter S. Galbraith <psg@debian.org> for maintaining emacs-goodies-el.
 294 ;;   * Dmitry Dzhus <mail@sphinx.net.ru> for reference checking functions.
 295 ;;   * Bryan Kyle <bryan.kyle@gmail.com> for indentation code.
 296 ;;   * Ben Voui <intrigeri@boum.org> for font-lock face customizations.
 297 ;;   * Ankit Solanki <ankit.solanki@gmail.com> for longlines.el
 298 ;;     compatibility and custom CSS.
 299 ;;   * Hilko Bengen <bengen@debian.org> for proper XHTML output.
 300 ;;   * Jose A. Ortega Ruiz <jao@gnu.org> for Emacs 23 fixes.
 301 ;;   * Alec Resnick <alec@sproutward.org> for bug reports.
 302 ;;   * Joost Kremers <j.kremers@em.uni-frankfurt.de> for bug reports
 303 ;;     regarding indentation.
 304 ;;   * Peter Williams <pezra@barelyenough.org> for fill-paragraph
 305 ;;     enhancements.
 306 ;;   * George Ogata <george.ogata@gmail.com> for fixing several
 307 ;;     byte-compilation warnings.
 308 ;;   * Eric Merritt <ericbmerritt@gmail.com> for wiki link features.
 309 ;;   * Philippe Ivaldi <pivaldi@sfr.fr> for XHTML preview
 310 ;;     customizations and XHTML export.
 311
 312 ;;; Bugs:
 313
 314 ;; Although markdown-mode is developed and tested primarily using
 315 ;; GNU Emacs 24, compatibility with earlier Emacsen is also a
 316 ;; priority.
 317 ;;
 318 ;; markdown-mode's syntax highlighting is accomplished using the
 319 ;; search-based fontification features of Emacs through a series of
 320 ;; regular expressions.  Unfortunately, Emacs has trouble highlighting
 321 ;; multi-line constructs using regular expressions and this creates
 322 ;; several syntax-highlighting quirks such as mistaking indented
 323 ;; lists for preformatted text, etc.  Making markdown-mode's syntax
 324 ;; highlighting more robust through the use of matching functions
 325 ;; or syntactic font lock is a high-priority item for future work.
 326 ;;
 327 ;; If you find any bugs not mentioned here, please construct a test
 328 ;; case and/or a patch and email me at <jrblevin@sdf.org>.
 329
 330 ;;; History:
 331
 332 ;; markdown-mode was written and is maintained by Jason Blevins.  The
 333 ;; first version was released on May 24, 2007.
 334 ;;
 335 ;;   * 2007-05-24: Version 1.1
 336 ;;   * 2007-05-25: Version 1.2
 337 ;;   * 2007-06-05: [Version 1.3][]
 338 ;;   * 2007-06-29: Version 1.4
 339 ;;   * 2008-05-24: [Version 1.5][]
 340 ;;   * 2008-06-04: [Version 1.6][]
 341 ;;   * 2009-10-01: [Version 1.7][]
 342 ;;
 343 ;; [Version 1.3]: http://jblevins.org/projects/markdown-mode/rev-1-3
 344 ;; [Version 1.5]: http://jblevins.org/projects/markdown-mode/rev-1-5
 345 ;; [Version 1.6]: http://jblevins.org/projects/markdown-mode/rev-1-6
 346 ;; [Version 1.7]: http://jblevins.org/projects/markdown-mode/rev-1-7
 347
 348 \f
 349 ;;; Code:
 350
 351 (require 'easymenu)
 352 (require 'outline)
 353
 354 ;;; Constants =================================================================
 355
 356 (defconst markdown-mode-version "1.7-dev"
 357   "Markdown mode version number.")
 358
 359 (defconst markdown-output-buffer-name "*markdown-output*"
 360   "Name of temporary buffer for markdown command output.")
 361
 362 ;;; Customizable variables ====================================================
 363
 364 (defvar markdown-mode-hook nil
 365   "Hook runs when Markdown mode is loaded.")
 366
 367 (defgroup markdown nil
 368   "Major mode for editing text files in Markdown format."
 369   :prefix "markdown-"
 370   :group 'wp
 371   :link '(url-link "http://jblevins.org/projects/markdown-mode/"))
 372
 373 (defcustom markdown-command "markdown"
 374   "Command to run markdown."
 375   :group 'markdown
 376   :type 'string)
 377
 378 (defcustom markdown-hr-length 5
 379   "Length of horizonal rules."
 380   :group 'markdown
 381   :type 'integer)
 382
 383 (defcustom markdown-bold-underscore nil
 384   "Use two underscores for bold instead of two asterisks."
 385   :group 'markdown
 386   :type 'boolean)
 387
 388 (defcustom markdown-italic-underscore nil
 389   "Use underscores for italic instead of asterisks."
 390   :group 'markdown
 391   :type 'boolean)
 392
 393 (defcustom markdown-indent-function 'markdown-indent-line
 394   "Function to use to indent."
 395   :group 'markdown
 396   :type 'function)
 397
 398 (defcustom markdown-indent-on-enter t
 399   "Automatically indent new lines when enter key is pressed."
 400   :group 'markdown
 401   :type 'boolean)
 402
 403 (defcustom markdown-follow-wiki-link-on-enter t
 404   "Follow wiki link at point (if any) when the enter key is pressed."
 405   :group 'markdown
 406   :type 'boolean)
 407
 408 (defcustom markdown-uri-types
 409   '("acap" "cid" "data" "dav" "fax" "file" "ftp" "gopher" "http" "https"
 410     "imap" "ldap" "mailto" "mid" "modem" "news" "nfs" "nntp" "pop" "prospero"
 411     "rtsp" "service" "sip" "tel" "telnet" "tip" "urn" "vemmi" "wais")
 412   "Link types for syntax highlighting of URIs."
 413   :group 'markdown
 414   :type 'list)
 415
 416 (defcustom markdown-enable-math nil
 417   "Syntax highlighting for inline LaTeX expressions.
 418 This will not take effect until Emacs is restarted."
 419   :group 'markdown
 420   :type 'boolean)
 421
 422 (defcustom markdown-css-path ""
 423   "URL of CSS file to link to in the output XHTML."
 424   :group 'markdown
 425   :type 'string)
 426
 427 (defcustom markdown-xhtml-header-content ""
 428   "Additional content to include in the XHTML <head> block."
 429   :group 'markdown
 430   :type 'string)
 431
 432 (defcustom markdown-xhtml-standalone-regexp
 433   "^\\(\<\?xml\\|\<!DOCTYPE\\|\<html\\)"
 434   "Regexp indicating whether `markdown-command' output is standalone XHTML."
 435   :group 'markdown
 436   :type 'regexp)
 437
 438 ;;; Font lock =================================================================
 439
 440 (require 'font-lock)
 441
 442 (defvar markdown-italic-face 'markdown-italic-face
 443   "Face name to use for italic text.")
 444
 445 (defvar markdown-bold-face 'markdown-bold-face
 446   "Face name to use for bold text.")
 447
 448 (defvar markdown-header-face 'markdown-header-face
 449   "Face name to use as a base for headers.")
 450
 451 (defvar markdown-header-face-1 'markdown-header-face-1
 452   "Face name to use for level-1 headers.")
 453
 454 (defvar markdown-header-face-2 'markdown-header-face-2
 455   "Face name to use for level-2 headers.")
 456
 457 (defvar markdown-header-face-3 'markdown-header-face-3
 458   "Face name to use for level-3 headers.")
 459
 460 (defvar markdown-header-face-4 'markdown-header-face-4
 461   "Face name to use for level-4 headers.")
 462
 463 (defvar markdown-header-face-5 'markdown-header-face-5
 464   "Face name to use for level-5 headers.")
 465
 466 (defvar markdown-header-face-6 'markdown-header-face-6
 467   "Face name to use for level-6 headers.")
 468
 469 (defvar markdown-inline-code-face 'markdown-inline-code-face
 470   "Face name to use for inline code.")
 471
 472 (defvar markdown-list-face 'markdown-list-face
 473   "Face name to use for list markers.")
 474
 475 (defvar markdown-blockquote-face 'markdown-blockquote-face
 476   "Face name to use for blockquote.")
 477
 478 (defvar markdown-pre-face 'markdown-pre-face
 479   "Face name to use for preformatted text.")
 480
 481 (defvar markdown-link-face 'markdown-link-face
 482   "Face name to use for links.")
 483
 484 (defvar markdown-missing-link-face 'markdown-missing-link-face
 485   "Face name to use for links where the linked file does not exist.")
 486
 487 (defvar markdown-reference-face 'markdown-reference-face
 488   "Face name to use for reference.")
 489
 490 (defvar markdown-url-face 'markdown-url-face
 491   "Face name to use for URLs.")
 492
 493 (defvar markdown-link-title-face 'markdown-link-title-face
 494   "Face name to use for reference link titles.")
 495
 496 (defvar markdown-comment-face 'markdown-comment-face
 497   "Face name to use for HTML comments.")
 498
 499 (defvar markdown-math-face 'markdown-math-face
 500   "Face name to use for LaTeX expressions.")
 501
 502 (defgroup markdown-faces nil
 503   "Faces used in Markdown Mode"
 504   :group 'markdown
 505   :group 'faces)
 506
 507 (defface markdown-italic-face
 508   '((t :inherit font-lock-variable-name-face :italic t))
 509   "Face for italic text."
 510   :group 'markdown-faces)
 511
 512 (defface markdown-bold-face
 513   '((t :inherit font-lock-variable-name-face :bold t))
 514   "Face for bold text."
 515   :group 'markdown-faces)
 516
 517 (defface markdown-header-face
 518   '((t :inherit font-lock-function-name-face :weight bold))
 519   "Base face for headers."
 520   :group 'markdown-faces)
 521
 522 (defface markdown-header-face-1
 523   '((t :inherit markdown-header-face))
 524   "Face for level-1 headers."
 525   :group 'markdown-faces)
 526
 527 (defface markdown-header-face-2
 528   '((t :inherit markdown-header-face))
 529   "Face for level-2 headers."
 530   :group 'markdown-faces)
 531
 532 (defface markdown-header-face-3
 533   '((t :inherit markdown-header-face))
 534   "Face for level-3 headers."
 535   :group 'markdown-faces)
 536
 537 (defface markdown-header-face-4
 538   '((t :inherit markdown-header-face))
 539   "Face for level-4 headers."
 540   :group 'markdown-faces)
 541
 542 (defface markdown-header-face-5
 543   '((t :inherit markdown-header-face))
 544   "Face for level-5 headers."
 545   :group 'markdown-faces)
 546
 547 (defface markdown-header-face-6
 548   '((t :inherit markdown-header-face))
 549   "Face for level-6 headers."
 550   :group 'markdown-faces)
 551
 552 (defface markdown-inline-code-face
 553   '((t :inherit font-lock-constant-face))
 554   "Face for inline code."
 555   :group 'markdown-faces)
 556
 557 (defface markdown-list-face
 558   '((t :inherit font-lock-builtin-face))
 559   "Face for list item markers."
 560   :group 'markdown-faces)
 561
 562 (defface markdown-blockquote-face
 563   '((t :inherit font-lock-doc-face))
 564   "Face for blockquote sections."
 565   :group 'markdown-faces)
 566
 567 (defface markdown-pre-face
 568   '((t :inherit font-lock-constant-face))
 569   "Face for preformatted text."
 570   :group 'markdown-faces)
 571
 572 (defface markdown-link-face
 573   '((t :inherit font-lock-keyword-face))
 574   "Face for links."
 575   :group 'markdown-faces)
 576
 577 (defface markdown-missing-link-face
 578   '((t :inherit font-lock-warning-face))
 579   "Face for missing links."
 580   :group 'markdown-faces)
 581
 582 (defface markdown-reference-face
 583   '((t :inherit font-lock-type-face))
 584   "Face for link references."
 585   :group 'markdown-faces)
 586
 587 (defface markdown-url-face
 588   '((t :inherit font-lock-string-face))
 589   "Face for URLs."
 590   :group 'markdown-faces)
 591
 592 (defface markdown-link-title-face
 593   '((t :inherit font-lock-comment-face))
 594   "Face for reference link titles."
 595   :group 'markdown-faces)
 596
 597 (defface markdown-comment-face
 598   '((t :inherit font-lock-comment-face))
 599   "Face for HTML comments."
 600   :group 'markdown-faces)
 601
 602 (defface markdown-math-face
 603   '((t :inherit font-lock-string-face))
 604   "Face for LaTeX expressions."
 605   :group 'markdown-faces)
 606
 607 (defconst markdown-regex-link-inline
 608   "\\(!?\\[[^]]*?\\]\\)\\(([^\\)]*)\\)"
 609   "Regular expression for a [text](file) or an image link ![text](file).")
 610
 611 (defconst markdown-regex-link-reference
 612   "\\(!?\\[[^]]+?\\]\\)[ ]?\\(\\[[^]]*?\\]\\)"
 613   "Regular expression for a reference link [text][id].")
 614
 615 (defconst markdown-regex-reference-definition
 616   "^ \\{0,3\\}\\(\\[.+?\\]\\):\\s *\\(.*?\\)\\s *\\( \"[^\"]*\"$\\|$\\)"
 617   "Regular expression for a link definition [id]: ...")
 618
 619 (defconst markdown-regex-header-1-atx
 620   "^\\(# \\)\\(.*?\\)\\($\\| #+$\\)"
 621   "Regular expression for level 1 atx-style (hash mark) headers.")
 622
 623 (defconst markdown-regex-header-2-atx
 624   "^\\(## \\)\\(.*?\\)\\($\\| #+$\\)"
 625   "Regular expression for level 2 atx-style (hash mark) headers.")
 626
 627 (defconst markdown-regex-header-3-atx
 628   "^\\(### \\)\\(.*?\\)\\($\\| #+$\\)"
 629   "Regular expression for level 3 atx-style (hash mark) headers.")
 630
 631 (defconst markdown-regex-header-4-atx
 632   "^\\(#### \\)\\(.*?\\)\\($\\| #+$\\)"
 633   "Regular expression for level 4 atx-style (hash mark) headers.")
 634
 635 (defconst markdown-regex-header-5-atx
 636   "^\\(##### \\)\\(.*?\\)\\($\\| #+$\\)"
 637   "Regular expression for level 5 atx-style (hash mark) headers.")
 638
 639 (defconst markdown-regex-header-6-atx
 640   "^\\(###### \\)\\(.*?\\)\\($\\| #+$\\)"
 641   "Regular expression for level 6 atx-style (hash mark) headers.")
 642
 643 (defconst markdown-regex-header-1-setext
 644   "^\\(.*\\)\n\\(===+\\)$"
 645   "Regular expression for level 1 setext-style (underline) headers.")
 646
 647 (defconst markdown-regex-header-2-setext
 648   "^\\(.*\\)\n\\(---+\\)$"
 649   "Regular expression for level 2 setext-style (underline) headers.")
 650
 651 (defconst markdown-regex-hr
 652   "^\\(\\*[ ]?\\*[ ]?\\*[ ]?[\\* ]*\\|-[ ]?-[ ]?-[--- ]*\\)$"
 653   "Regular expression for matching Markdown horizontal rules.")
 654
 655 (defconst markdown-regex-code
 656   "\\(^\\|[^\\]\\)\\(\\(`\\{1,2\\}\\)\\([^ \\]\\|[^ ].*?[^ \\]\\)\\3\\)"
 657   "Regular expression for matching inline code fragments.")
 658
 659 (defconst markdown-regex-pre
 660   "^\\(    \\|\t\\).*$"
 661   "Regular expression for matching preformatted text sections.")
 662
 663 (defconst markdown-regex-list
 664   "^[ \t]*\\([0-9]+\\.\\|[\\*\\+-]\\) "
 665   "Regular expression for matching list markers.")
 666
 667 (defconst markdown-regex-bold
 668   "\\(^\\|[^\\]\\)\\(\\([*_]\\{2\\}\\)\\(.\\|\n\\)*?[^\\ ]\\3\\)"
 669   "Regular expression for matching bold text.")
 670
 671 (defconst markdown-regex-italic
 672   "\\(^\\|[^\\]\\)\\(\\([*_]\\)\\([^ \\]\\3\\|[^ ]\\(.\\|\n\\)*?[^\\ ]\\3\\)\\)"
 673   "Regular expression for matching italic text.")
 674
 675 (defconst markdown-regex-blockquote
 676   "^>.*$"
 677   "Regular expression for matching blockquote lines.")
 678
 679 (defconst markdown-regex-line-break
 680   "  $"
 681   "Regular expression for matching line breaks.")
 682
 683 (defconst markdown-regex-wiki-link
 684   "\\[\\[\\([^]]+\\)\\]\\]"
 685   "Regular expression for matching wiki links.")
 686
 687 (defconst markdown-regex-uri
 688   (concat
 689    "\\(" (mapconcat 'identity markdown-uri-types "\\|")
 690    "\\):[^]\t\n\r<>,;() ]+")
 691   "Regular expression for matching inline URIs.")
 692
 693 (defconst markdown-regex-angle-uri
 694   (concat
 695    "\\(<\\)\\("
 696    (mapconcat 'identity markdown-uri-types "\\|")
 697    "\\):[^]\t\n\r<>,;()]+\\(>\\)")
 698   "Regular expression for matching inline URIs in angle brackets.")
 699
 700 (defconst markdown-regex-email
 701   "<\\(\\sw\\|\\s_\\|\\s.\\)+@\\(\\sw\\|\\s_\\|\\s.\\)+>"
 702   "Regular expression for matching inline email addresses.")
 703
 704 (defconst markdown-regex-latex-expression
 705   "\\(^\\|[^\\]\\)\\(\\$\\($\\([^\\$]\\|\\\\.\\)*\\$\\|\\([^\\$]\\|\\\\.\\)*\\)\\$\\)"
 706   "Regular expression for itex $..$ or $$..$$ math mode expressions.")
 707
 708 (defconst markdown-regex-latex-display
 709     "^\\\\\\[\\(.\\|\n\\)*?\\\\\\]$"
 710   "Regular expression for itex \[..\] display mode expressions.")
 711
 712 (defconst markdown-regex-list-indent
 713   "^\\(\\s *\\)\\([0-9]+\\.\\|[\\*\\+-]\\)\\(\\s +\\)"
 714   "Regular expression for matching indentation of list items.")
 715
 716 (defvar markdown-mode-font-lock-keywords-basic
 717   (list
 718    '(markdown-match-comments 0 markdown-comment-face t t)
 719    (cons markdown-regex-code '(2 markdown-inline-code-face))
 720    (cons markdown-regex-pre 'markdown-pre-face)
 721    (cons markdown-regex-blockquote 'markdown-blockquote-face)
 722    (cons markdown-regex-header-1-setext 'markdown-header-face-1)
 723    (cons markdown-regex-header-2-setext 'markdown-header-face-2)
 724    (cons markdown-regex-header-1-atx 'markdown-header-face-1)
 725    (cons markdown-regex-header-2-atx 'markdown-header-face-2)
 726    (cons markdown-regex-header-3-atx 'markdown-header-face-3)
 727    (cons markdown-regex-header-4-atx 'markdown-header-face-4)
 728    (cons markdown-regex-header-5-atx 'markdown-header-face-5)
 729    (cons markdown-regex-header-6-atx 'markdown-header-face-6)
 730    (cons markdown-regex-hr 'markdown-header-face)
 731    (cons markdown-regex-list 'markdown-list-face)
 732    (cons markdown-regex-link-inline
 733          '((1 markdown-link-face t)
 734            (2 markdown-url-face t)))
 735    (cons markdown-regex-link-reference
 736          '((1 markdown-link-face t)
 737            (2 markdown-reference-face t)))
 738    (cons markdown-regex-reference-definition
 739          '((1 markdown-reference-face t)
 740            (2 markdown-url-face t)
 741            (3 markdown-link-title-face t)))
 742    (cons markdown-regex-bold '(2 markdown-bold-face))
 743    (cons markdown-regex-italic '(2 markdown-italic-face))
 744    (cons markdown-regex-angle-uri 'markdown-link-face)
 745    (cons markdown-regex-uri 'markdown-link-face)
 746    (cons markdown-regex-email 'markdown-link-face)
 747    )
 748   "Syntax highlighting for Markdown files.")
 749
 750 (defconst markdown-mode-font-lock-keywords-latex
 751   (list
 752    ;; Math mode $..$ or $$..$$
 753    (cons markdown-regex-latex-expression '(2 markdown-math-face))
 754    ;; Display mode equations with brackets: \[ \]
 755    (cons markdown-regex-latex-display 'markdown-math-face)
 756    ;; Equation reference (eq:foo)
 757    (cons "(eq:\\w+)" 'markdown-reference-face)
 758    ;; Equation reference \eqref{foo}
 759    (cons "\\\\eqref{\\w+}" 'markdown-reference-face))
 760   "Syntax highlighting for LaTeX fragments.")
 761
 762 (defvar markdown-mode-font-lock-keywords
 763   (append
 764    (if markdown-enable-math
 765        markdown-mode-font-lock-keywords-latex)
 766    markdown-mode-font-lock-keywords-basic)
 767   "Default highlighting expressions for Markdown mode.")
 768
 769 \f
 770
 771 ;;; Markdown parsing functions ================================================
 772
 773 (defun markdown-prev-line-blank-p ()
 774   "Return t if the previous line is blank and nil otherwise."
 775   (save-excursion
 776     (forward-line -1)
 777     (goto-char (point-at-bol))
 778     (if (re-search-forward "^\\s *$" (point-at-eol) t) t)))
 779
 780 (defun markdown-prev-line-indent-p ()
 781   "Return t if the previous line is indented and nil otherwise."
 782   (save-excursion
 783     (forward-line -1)
 784     (goto-char (point-at-bol))
 785     (if (re-search-forward "^\\s " (point-at-eol) t) t)))
 786
 787 (defun markdown-cur-line-indent ()
 788   "Return the number of leading whitespace characters in the current line."
 789   (save-excursion
 790     (goto-char (point-at-bol))
 791     (re-search-forward "^\\s +" (point-at-eol) t)
 792     (current-column)))
 793
 794 (defun markdown-prev-line-indent ()
 795   "Return the number of leading whitespace characters in the previous line."
 796   (save-excursion
 797     (forward-line -1)
 798     (markdown-cur-line-indent)))
 799
 800 (defun markdown-prev-non-list-indent ()
 801   "Return position of the first non-list-marker on the previous line."
 802   (save-excursion
 803     (forward-line -1)
 804     (goto-char (point-at-bol))
 805     (when (re-search-forward markdown-regex-list-indent (point-at-eol) t)
 806         (current-column))))
 807
 808 ; From html-helper-mode
 809 (defun markdown-match-comments (last)
 810   "Match HTML comments from the point to LAST."
 811   (cond ((search-forward "<!--" last t)
 812          (backward-char 4)
 813          (let ((beg (point)))
 814            (cond ((search-forward-regexp "--[ \t]*>" last t)
 815                   (set-match-data (list beg (point)))
 816                   t)
 817                  (t nil))))
 818         (t nil)))
 819
 820 \f
 821
 822 ;;; Syntax Table ==============================================================
 823
 824 (defvar markdown-mode-syntax-table
 825   (let ((markdown-mode-syntax-table (make-syntax-table)))
 826     (modify-syntax-entry ?\" "w" markdown-mode-syntax-table)
 827     markdown-mode-syntax-table)
 828   "Syntax table for `markdown-mode'.")
 829
 830 \f
 831
 832 ;;; Element Insertion =========================================================
 833
 834 (defun markdown-wrap-or-insert (s1 s2)
 835  "Insert the strings S1 and S2.
 836 If Transient Mark mode is on and a region is active, wrap the strings S1
 837 and S2 around the region."
 838  (if (and transient-mark-mode mark-active)
 839      (let ((a (region-beginning)) (b (region-end)))
 840        (goto-char a)
 841        (insert s1)
 842        (goto-char (+ b (length s1)))
 843        (insert s2))
 844    (insert s1 s2)))
 845
 846 (defun markdown-insert-hr ()
 847   "Insert a horizonal rule."
 848   (interactive)
 849   (let (hr)
 850     (dotimes (count (- markdown-hr-length 1) hr)        ; Count to n - 1
 851       (setq hr (concat "* " hr)))                       ; Build HR string
 852     (setq hr (concat hr "*\n"))                         ; Add the n-th *
 853     (insert hr)))
 854
 855 (defun markdown-insert-bold ()
 856   "Insert markup for a bold word or phrase.
 857 If Transient Mark mode is on and a region is active, it is made bold."
 858   (interactive)
 859   (if markdown-bold-underscore
 860       (markdown-wrap-or-insert "__" "__")
 861     (markdown-wrap-or-insert "**" "**"))
 862   (backward-char 2))
 863
 864 (defun markdown-insert-italic ()
 865   "Insert markup for an italic word or phrase.
 866 If Transient Mark mode is on and a region is active, it is made italic."
 867   (interactive)
 868   (if markdown-italic-underscore
 869       (markdown-wrap-or-insert "_" "_")
 870     (markdown-wrap-or-insert "*" "*"))
 871   (backward-char 1))
 872
 873 (defun markdown-insert-code ()
 874   "Insert markup for an inline code fragment.
 875 If Transient Mark mode is on and a region is active, it is marked
 876 as inline code."
 877   (interactive)
 878   (markdown-wrap-or-insert "`" "`")
 879   (backward-char 1))
 880
 881 (defun markdown-insert-link ()
 882   "Insert an inline link of the form []().
 883 If Transient Mark mode is on and a region is active, it is used
 884 as the link text."
 885   (interactive)
 886   (markdown-wrap-or-insert "[" "]")
 887   (insert "()")
 888   (backward-char 1))
 889
 890 (defun markdown-insert-wiki-link ()
 891   "Insert a wiki link of the form [[WikiLink]].
 892 If Transient Mark mode is on and a region is active, it is used
 893 as the link text."
 894   (interactive)
 895   (markdown-wrap-or-insert "[[" "]]")
 896   (backward-char 2))
 897
 898 (defun markdown-insert-image ()
 899   "Insert an inline image tag of the form ![]().
 900 If Transient Mark mode is on and a region is active, it is used
 901 as the alt text of the image."
 902   (interactive)
 903   (markdown-wrap-or-insert "![" "]")
 904   (insert "()")
 905   (backward-char 1))
 906
 907 (defun markdown-insert-header-1 ()
 908   "Insert a first level atx-style (hash mark) header.
 909 If Transient Mark mode is on and a region is active, it is used
 910 as the header text."
 911   (interactive)
 912   (markdown-insert-header 1))
 913
 914 (defun markdown-insert-header-2 ()
 915   "Insert a second level atx-style (hash mark) header.
 916 If Transient Mark mode is on and a region is active, it is used
 917 as the header text."
 918   (interactive)
 919   (markdown-insert-header 2))
 920
 921 (defun markdown-insert-header-3 ()
 922   "Insert a third level atx-style (hash mark) header.
 923 If Transient Mark mode is on and a region is active, it is used
 924 as the header text."
 925   (interactive)
 926   (markdown-insert-header 3))
 927
 928 (defun markdown-insert-header-4 ()
 929   "Insert a fourth level atx-style (hash mark) header.
 930 If Transient Mark mode is on and a region is active, it is used
 931 as the header text."
 932   (interactive)
 933   (markdown-insert-header 4))
 934
 935 (defun markdown-insert-header-5 ()
 936   "Insert a fifth level atx-style (hash mark) header.
 937 If Transient Mark mode is on and a region is active, it is used
 938 as the header text."
 939   (interactive)
 940   (markdown-insert-header 5))
 941
 942 (defun markdown-insert-header-6 ()
 943   "Insert a sixth level atx-style (hash mark) header.
 944 If Transient Mark mode is on and a region is active, it is used
 945 as the header text."
 946   (interactive)
 947   (markdown-insert-header 6))
 948
 949 (defun markdown-insert-header (n)
 950   "Insert an atx-style (hash mark) header.
 951 With no prefix argument, insert a level-1 header.  With prefix N,
 952 insert a level-N header.  If Transient Mark mode is on and the
 953 region is active, it is used as the header text."
 954   (interactive "p")
 955   (unless n                             ; Test to see if n is defined
 956     (setq n 1))                         ; Default to level 1 header
 957   (let (hdr hdrl hdrr)
 958     (dotimes (count n hdr)
 959       (setq hdr (concat "#" hdr)))      ; Build a hash mark header string
 960     (setq hdrl (concat hdr " "))
 961     (setq hdrr (concat " " hdr))
 962     (markdown-wrap-or-insert hdrl hdrr))
 963   (backward-char (+ 1 n)))
 964
 965 (defun markdown-insert-title ()
 966   "Insert a setext-style (underline) first level header.
 967 If Transient Mark mode is on and a region is active, it is used
 968 as the header text."
 969   (interactive)
 970   (if (and transient-mark-mode mark-active)
 971       (let ((a (region-beginning))
 972             (b (region-end))
 973             (len 0)
 974             (hdr))
 975         (setq len (- b a))
 976         (dotimes (count len hdr)
 977           (setq hdr (concat "=" hdr)))  ; Build a === title underline
 978         (end-of-line)
 979         (insert "\n" hdr "\n"))
 980     (insert "\n==========\n")
 981     (backward-char 12)))
 982
 983 (defun markdown-insert-section ()
 984   "Insert a setext-style (underline) second level header.
 985 If Transient Mark mode is on and a region is active, it is used
 986 as the header text."
 987   (interactive)
 988   (if (and transient-mark-mode mark-active)
 989       (let ((a (region-beginning))
 990             (b (region-end))
 991             (len 0)
 992             (hdr))
 993         (setq len (- b a))
 994         (dotimes (count len hdr)
 995           (setq hdr (concat "-" hdr)))  ; Build a --- section underline
 996         (end-of-line)
 997         (insert "\n" hdr "\n"))
 998     (insert "\n----------\n")
 999     (backward-char 12)))
1000
1001 (defun markdown-insert-blockquote ()
1002   "Start a blockquote section (or blockquote the region).
1003 If Transient Mark mode is on and a region is active, it is used as
1004 the blockquote text."
1005   (interactive)
1006   (if (and (boundp 'transient-mark-mode) transient-mark-mode mark-active)
1007       (markdown-blockquote-region (region-beginning) (region-end))
1008     (insert "> ")))
1009
1010 (defun markdown-block-region (beg end prefix)
1011   "Format the region using a block prefix.
1012 Arguments BEG and END specify the beginning and end of the
1013 region.The characters PREFIX will appear at the beginning
1014 of each line."
1015   (if mark-active
1016       (save-excursion
1017         (let ((endpos end))
1018           ; Ensure that there is a leading blank line
1019           (goto-char beg)
1020           (while (not (looking-back "\n\n" 2))
1021             (insert "\n")
1022             (setq endpos (+ 1 endpos)))
1023           ; Insert blockquote characters
1024           (move-to-left-margin)
1025           (while (< (point-at-bol) endpos)
1026             (insert prefix)
1027             (setq endpos (+ (length prefix) endpos))
1028             (forward-line))
1029           ; Move back before any blank lines at the end
1030           (goto-char endpos)
1031           (while (looking-back "\n" 1)
1032             (backward-char))
1033           ; Ensure one blank line at the end
1034           (while (not (looking-at "\n\n"))
1035             (insert "\n")
1036             (backward-char))))))
1037
1038 (defun markdown-blockquote-region (beg end)
1039   "Blockquote the region.
1040 Arguments BEG and END specify the beginning and end of the region."
1041   (interactive "*r")
1042   (markdown-block-region beg end "> "))
1043
1044 (defun markdown-insert-pre ()
1045   "Start a preformatted section (or apply to the region).
1046 If Transient Mark mode is on and a region is active, it is marked
1047 as preformatted text."
1048   (interactive)
1049   (if (and (boundp 'transient-mark-mode) transient-mark-mode mark-active)
1050       (markdown-pre-region (region-beginning) (region-end))
1051     (insert "    ")))
1052
1053 (defun markdown-pre-region (beg end)
1054   "Format the region as preformatted text.
1055 Arguments BEG and END specify the beginning and end of the region."
1056   (interactive "*r")
1057   (markdown-block-region beg end "    "))
1058
1059 ;;; Indentation ====================================================================
1060
1061 (defun markdown-indent-find-next-position (cur-pos positions)
1062   "Return the position after the index of CUR-POS in POSITIONS."
1063   (while (and positions
1064               (not (equal cur-pos (car positions))))
1065     (setq positions (cdr positions)))
1066   (or (cadr positions) 0))
1067
1068 (defun markdown-indent-line ()
1069   "Indent the current line using some heuristics."
1070   (interactive)
1071   (if (markdown-prev-line-indent-p)
1072       ;; If the current column is any of the positions, remove all
1073       ;; of the positions up-to and including the current column
1074       (indent-line-to
1075        (markdown-indent-find-next-position
1076         (current-column) (markdown-calc-indents)))))
1077
1078 (defun markdown-calc-indents ()
1079   "Return a list of indentation columns to cycle through."
1080   (let (pos
1081         prev-line-pos
1082         positions
1083         computed-pos)
1084
1085     ;; Previous line indent
1086     (setq prev-line-pos (markdown-prev-line-indent))
1087     (setq positions (cons prev-line-pos positions))
1088
1089     ;; Previous non-list-marker indent
1090     (setq pos (markdown-prev-non-list-indent))
1091     (if pos
1092         (setq positions (cons pos positions)))
1093
1094     ;; Indentation of the previous line + tab-width
1095     (cond
1096      (prev-line-pos
1097       (setq positions (cons (+ prev-line-pos tab-width) positions)))
1098      (t
1099       (setq positions (cons tab-width positions))))
1100
1101     ;; Indentation of the previous line - tab-width
1102     (if (and prev-line-pos
1103              (> prev-line-pos tab-width))
1104         (setq positions (cons (- prev-line-pos tab-width) positions)))
1105
1106     ;; Indentation of preceeding list item
1107     (setq pos
1108           (save-excursion
1109             (forward-line -1)
1110             (catch 'break
1111               (while (not (equal (point) (point-min)))
1112                 (forward-line -1)
1113                 (goto-char (point-at-bol))
1114                 (when (re-search-forward markdown-regex-list-indent (point-at-eol) t)
1115                   (throw 'break (length (match-string 1)))))
1116               nil)))
1117     (if (and pos (not (eq pos prev-line-pos)))
1118         (setq positions (cons pos positions)))
1119
1120     ;; First column
1121     (setq positions (cons 0 (reverse positions)))
1122
1123     positions))
1124
1125 (defun markdown-do-normal-return ()
1126   "Insert a newline and optionally indent the next line."
1127   (newline)
1128   (if markdown-indent-on-enter
1129       (funcall indent-line-function)))
1130
1131 (defun markdown-enter-key ()
1132   "Handle RET according to context.
1133 If there is a wiki link at the point, follow it unless
1134 `markdown-follow-wiki-link-on-enter' is nil.  Otherwise, process
1135 it in the usual way."
1136   (interactive)
1137   (if (and markdown-follow-wiki-link-on-enter (markdown-wiki-link-p))
1138       (markdown-follow-wiki-link-at-point)
1139     (markdown-do-normal-return)))
1140
1141 \f
1142
1143 ;;; Keymap ====================================================================
1144
1145 (defvar markdown-mode-map
1146   (let ((map (make-keymap)))
1147     ;; Element insertion
1148     (define-key map "\C-c\C-al" 'markdown-insert-link)
1149     (define-key map "\C-c\C-aw" 'markdown-insert-wiki-link)
1150     (define-key map "\C-c\C-ii" 'markdown-insert-image)
1151     (define-key map "\C-c\C-t1" 'markdown-insert-header-1)
1152     (define-key map "\C-c\C-t2" 'markdown-insert-header-2)
1153     (define-key map "\C-c\C-t3" 'markdown-insert-header-3)
1154     (define-key map "\C-c\C-t4" 'markdown-insert-header-4)
1155     (define-key map "\C-c\C-t5" 'markdown-insert-header-5)
1156     (define-key map "\C-c\C-t6" 'markdown-insert-header-6)
1157     (define-key map "\C-c\C-pb" 'markdown-insert-bold)
1158     (define-key map "\C-c\C-ss" 'markdown-insert-bold)
1159     (define-key map "\C-c\C-pi" 'markdown-insert-italic)
1160     (define-key map "\C-c\C-se" 'markdown-insert-italic)
1161     (define-key map "\C-c\C-pf" 'markdown-insert-code)
1162     (define-key map "\C-c\C-sc" 'markdown-insert-code)
1163     (define-key map "\C-c\C-sb" 'markdown-insert-blockquote)
1164     (define-key map "\C-c\C-s\C-b" 'markdown-blockquote-region)
1165     (define-key map "\C-c\C-sp" 'markdown-insert-pre)
1166     (define-key map "\C-c\C-s\C-p" 'markdown-pre-region)
1167     (define-key map "\C-c-" 'markdown-insert-hr)
1168     (define-key map "\C-c\C-tt" 'markdown-insert-title)
1169     (define-key map "\C-c\C-ts" 'markdown-insert-section)
1170     ;; WikiLink Following
1171     (define-key map "\C-c\C-f" 'markdown-follow-wiki-link-at-point)
1172     (define-key map "\M-n" 'markdown-next-wiki-link)
1173     (define-key map "\M-p" 'markdown-previous-wiki-link)
1174     ;; Indentation
1175     (define-key map "\C-m" 'markdown-enter-key)
1176     ;; Visibility cycling
1177     (define-key map (kbd "<tab>") 'markdown-cycle)
1178     (define-key map (kbd "<S-iso-lefttab>") 'markdown-shifttab)
1179     ;; Markdown functions
1180     (define-key map "\C-c\C-cm" 'markdown)
1181     (define-key map "\C-c\C-cp" 'markdown-preview)
1182     (define-key map "\C-c\C-ce" 'markdown-export)
1183     (define-key map "\C-c\C-cv" 'markdown-export-and-view)
1184     ;; References
1185     (define-key map "\C-c\C-cc" 'markdown-check-refs)
1186     map)
1187   "Keymap for Markdown major mode.")
1188
1189 ;;; Menu ==================================================================
1190
1191 (easy-menu-define markdown-mode-menu markdown-mode-map
1192   "Menu for Markdown mode"
1193   '("Markdown"
1194     ("Show/Hide"
1195      ["Cycle visibility" markdown-cycle (outline-on-heading-p)]
1196      ["Cycle global visibility" markdown-shifttab])
1197     "---"
1198     ["Compile" markdown]
1199     ["Preview" markdown-preview]
1200     ["Export" markdown-export]
1201     ["Export & View" markdown-export-and-view]
1202     "---"
1203     ("Headers (setext)"
1204      ["Insert Title" markdown-insert-title]
1205      ["Insert Section" markdown-insert-section])
1206     ("Headers (atx)"
1207      ["First level" markdown-insert-header-1]
1208      ["Second level" markdown-insert-header-2]
1209      ["Third level" markdown-insert-header-3]
1210      ["Fourth level" markdown-insert-header-4]
1211      ["Fifth level" markdown-insert-header-5]
1212      ["Sixth level" markdown-insert-header-6])
1213     "---"
1214     ["Bold" markdown-insert-bold]
1215     ["Italic" markdown-insert-italic]
1216     ["Blockquote" markdown-insert-blockquote]
1217     ["Preformatted" markdown-insert-pre]
1218     ["Code" markdown-insert-code]
1219     "---"
1220     ["Insert inline link" markdown-insert-link]
1221     ["Insert image" markdown-insert-image]
1222     ["Insert horizontal rule" markdown-insert-hr]
1223     "---"
1224     ["Check references" markdown-check-refs]
1225     "---"
1226     ["Version" markdown-show-version]
1227     ))
1228
1229 \f
1230
1231 ;;; References ================================================================
1232
1233 ;;; Undefined reference checking code by Dmitry Dzhus <mail@sphinx.net.ru>.
1234
1235 (defconst markdown-refcheck-buffer
1236   "*Undefined references for %BUFFER%*"
1237   "Pattern for name of buffer for listing undefined references.
1238 The string %BUFFER% will be replaced by the corresponding
1239 `markdown-mode' buffer name.")
1240
1241 (defun markdown-has-reference-definition (reference)
1242     "Find out whether Markdown REFERENCE is defined.
1243
1244 REFERENCE should include the square brackets, like [this]."
1245     (let ((reference (downcase reference)))
1246       (save-excursion
1247         (goto-char (point-min))
1248         (catch 'found
1249           (while (re-search-forward markdown-regex-reference-definition nil t)
1250             (when (string= reference (downcase (match-string-no-properties 1)))
1251               (throw 'found t)))))))
1252
1253 (defun markdown-get-undefined-refs ()
1254   "Return a list of undefined Markdown references.
1255
1256 Result is an alist of pairs (reference . occurencies), where
1257 occurencies is itself another alist of pairs (label .
1258 line-number).
1259
1260 For example, an alist corresponding to [Nice editor][Emacs] at line 12,
1261 \[GNU Emacs][Emacs] at line 45 and [manual][elisp] at line 127 is
1262 \((\"[emacs]\" (\"[Nice editor]\" . 12) (\"[GNU Emacs]\" . 45)) (\"[elisp]\" (\"[manual]\" . 127)))."
1263   (let ((missing))
1264     (save-excursion
1265       (goto-char (point-min))
1266       (while
1267           (re-search-forward markdown-regex-link-reference nil t)
1268         (let* ((label (match-string-no-properties 1))
1269                (reference (match-string-no-properties 2))
1270                (target (downcase (if (string= reference "[]") label reference))))
1271           (unless (markdown-has-reference-definition target)
1272             (let ((entry (assoc target missing)))
1273               (if (not entry)
1274                   (add-to-list 'missing (cons target
1275                                               (list (cons label (markdown-line-number-at-pos)))) t)
1276                 (setcdr entry
1277                         (append (cdr entry) (list (cons label (markdown-line-number-at-pos))))))))))
1278       missing)))
1279
1280 (defun markdown-add-missing-ref-definition (ref buffer &optional recheck)
1281   "Add blank REF definition to the end of BUFFER.
1282
1283 REF is a Markdown reference in square brackets, like \"[lisp-history]\".
1284
1285 When RECHECK is non-nil, BUFFER gets rechecked for undefined
1286 references so that REF disappears from the list of those links."
1287   (with-current-buffer buffer
1288       (when (not (eq major-mode 'markdown-mode))
1289         (error "Not available in current mode"))
1290       (goto-char (point-max))
1291       (indent-new-comment-line)
1292       (insert (concat ref ": ")))
1293   (switch-to-buffer-other-window buffer)
1294   (goto-char (point-max))
1295   (when recheck
1296     (markdown-check-refs t)))
1297
1298 ;; Button which adds an empty Markdown reference definition to the end
1299 ;; of buffer specified as its 'target-buffer property. Reference name
1300 ;; is button's label
1301 (when (>= emacs-major-version 22)
1302   (define-button-type 'markdown-ref-button
1303     'help-echo "Push to create an empty reference definition"
1304     'face 'bold
1305     'action (lambda (b)
1306               (markdown-add-missing-ref-definition
1307                (button-label b) (button-get b 'target-buffer) t))))
1308
1309 ;; Button jumping to line in buffer specified as its 'target-buffer
1310 ;; property. Line number is button's 'line property.
1311 (when (>= emacs-major-version 22)
1312   (define-button-type 'goto-line-button
1313     'help-echo "Push to go to this line"
1314     'face 'italic
1315     'action (lambda (b)
1316               (message (button-get b 'buffer))
1317               (switch-to-buffer-other-window (button-get b 'target-buffer))
1318               ;; use call-interactively to silence compiler
1319               (call-interactively 'goto-line (button-get b 'target-line)))))
1320
1321 (defun markdown-check-refs (&optional silent)
1322   "Show all undefined Markdown references in current `markdown-mode' buffer.
1323
1324 If SILENT is non-nil, do not message anything when no undefined
1325 references found.
1326
1327 Links which have empty reference definitions are considered to be
1328 defined."
1329   (interactive "P")
1330   (when (not (eq major-mode 'markdown-mode))
1331     (error "Not available in current mode"))
1332   (let ((oldbuf (current-buffer))
1333         (refs (markdown-get-undefined-refs))
1334         (refbuf (get-buffer-create (replace-regexp-in-string
1335                                  "%BUFFER%" (buffer-name)
1336                                  markdown-refcheck-buffer t))))
1337     (if (null refs)
1338         (progn
1339           (when (not silent)
1340             (message "No undefined references found"))
1341           (kill-buffer refbuf))
1342       (with-current-buffer refbuf
1343         (when view-mode
1344           (View-exit-and-edit))
1345         (erase-buffer)
1346         (insert "Following references lack definitions:")
1347         (newline 2)
1348         (dolist (ref refs)
1349           (let ((button-label (format "%s" (car ref))))
1350             (if (>= emacs-major-version 22)
1351                 ;; Create a reference button in Emacs 22
1352                 (insert-text-button button-label
1353                                     :type 'markdown-ref-button
1354                                     'target-buffer oldbuf)
1355               ;; Insert reference as text in Emacs < 22
1356               (insert button-label)))
1357           (insert " (")
1358           (dolist (occurency (cdr ref))
1359             (let ((line (cdr occurency)))
1360               (if (>= emacs-major-version 22)
1361                   ;; Create a line number button in Emacs 22
1362                   (insert-button (number-to-string line)
1363                                  :type 'goto-line-button
1364                                  'target-buffer oldbuf
1365                                  'target-line line)
1366                 ;; Insert line number as text in Emacs < 22
1367                 (insert (number-to-string line)))
1368               (insert " "))) (delete-char -1)
1369           (insert ")")
1370           (newline))
1371         (view-buffer-other-window refbuf)
1372         (goto-char (point-min))
1373         (forward-line 2)))))
1374
1375 ;;; Outline ===================================================================
1376
1377 ;; The following visibility cycling code was taken from org-mode
1378 ;; by Carsten Dominik and adapted for markdown-mode.
1379
1380 (defvar markdown-cycle-global-status 1)
1381 (defvar markdown-cycle-subtree-status nil)
1382
1383 ;; Based on org-end-of-subtree from org.el
1384 (defun markdown-end-of-subtree (&optional invisible-OK)
1385   "Move to the end of the current subtree.
1386 Only visible heading lines are considered, unless INVISIBLE-OK is
1387 non-nil."
1388   (outline-back-to-heading invisible-OK)
1389   (let ((first t)
1390         (level (funcall outline-level)))
1391     (while (and (not (eobp))
1392                 (or first (> (funcall outline-level) level)))
1393       (setq first nil)
1394       (outline-next-heading))
1395     (if (memq (preceding-char) '(?\n ?\^M))
1396         (progn
1397           ;; Go to end of line before heading
1398           (forward-char -1)
1399           (if (memq (preceding-char) '(?\n ?\^M))
1400               ;; leave blank line before heading
1401               (forward-char -1)))))
1402   (point))
1403
1404 ;; Based on org-cycle from org.el.
1405 (defun markdown-cycle (&optional arg)
1406   "Visibility cycling for Markdown mode.
1407 If ARG is t, perform global visibility cycling.  If the point is
1408 at an atx-style header, cycle visibility of the corresponding
1409 subtree.  Otherwise, insert a tab using `indent-relative'."
1410   (interactive "P")
1411   (cond
1412      ((eq arg t) ;; Global cycling
1413       (cond
1414        ((and (eq last-command this-command)
1415              (eq markdown-cycle-global-status 2))
1416         ;; Move from overview to contents
1417         (hide-sublevels 1)
1418         (message "CONTENTS")
1419         (setq markdown-cycle-global-status 3))
1420
1421        ((and (eq last-command this-command)
1422              (eq markdown-cycle-global-status 3))
1423         ;; Move from contents to all
1424         (show-all)
1425         (message "SHOW ALL")
1426         (setq markdown-cycle-global-status 1))
1427
1428        (t
1429         ;; Defaults to overview
1430         (hide-body)
1431         (message "OVERVIEW")
1432         (setq markdown-cycle-global-status 2))))
1433
1434      ((save-excursion (beginning-of-line 1) (looking-at outline-regexp))
1435       ;; At a heading: rotate between three different views
1436       (outline-back-to-heading)
1437       (let ((goal-column 0) eoh eol eos)
1438         ;; Determine boundaries
1439         (save-excursion
1440           (outline-back-to-heading)
1441           (save-excursion
1442             (beginning-of-line 2)
1443             (while (and (not (eobp)) ;; this is like `next-line'
1444                         (get-char-property (1- (point)) 'invisible))
1445               (beginning-of-line 2)) (setq eol (point)))
1446           (outline-end-of-heading)   (setq eoh (point))
1447           (markdown-end-of-subtree t)
1448           (skip-chars-forward " \t\n")
1449           (beginning-of-line 1) ; in case this is an item
1450           (setq eos (1- (point))))
1451         ;; Find out what to do next and set `this-command'
1452       (cond
1453          ((= eos eoh)
1454           ;; Nothing is hidden behind this heading
1455           (message "EMPTY ENTRY")
1456           (setq markdown-cycle-subtree-status nil))
1457          ((>= eol eos)
1458           ;; Entire subtree is hidden in one line: open it
1459           (show-entry)
1460           (show-children)
1461           (message "CHILDREN")
1462           (setq markdown-cycle-subtree-status 'children))
1463          ((and (eq last-command this-command)
1464                (eq markdown-cycle-subtree-status 'children))
1465           ;; We just showed the children, now show everything.
1466           (show-subtree)
1467           (message "SUBTREE")
1468           (setq markdown-cycle-subtree-status 'subtree))
1469          (t
1470           ;; Default action: hide the subtree.
1471           (hide-subtree)
1472           (message "FOLDED")
1473           (setq markdown-cycle-subtree-status 'folded)))))
1474
1475      (t
1476       (funcall indent-line-function))))
1477
1478 ;; Based on org-shifttab from org.el.
1479 (defun markdown-shifttab ()
1480   "Global visibility cycling.
1481 Calls `markdown-cycle' with argument t."
1482   (interactive)
1483   (markdown-cycle t))
1484
1485 ;;; Commands ==================================================================
1486
1487 (defun markdown (&optional output-buffer-name)
1488   "Run `markdown' on current buffer and insert output in buffer BUFFER-OUTPUT."
1489   (interactive)
1490   (let ((title (buffer-name))
1491         (begin-region)
1492         (end-region))
1493     (if (and (boundp 'transient-mark-mode) transient-mark-mode mark-active)
1494         (setq begin-region (region-beginning)
1495               end-region (region-end))
1496       (setq begin-region (point-min)
1497             end-region (point-max)))
1498
1499     (unless output-buffer-name
1500       (setq output-buffer-name markdown-output-buffer-name))
1501
1502     (shell-command-on-region begin-region end-region markdown-command
1503                              output-buffer-name)
1504     (save-current-buffer
1505       (set-buffer output-buffer-name)
1506       (goto-char (point-min))
1507       (unless (markdown-output-standalone-p)
1508         (markdown-add-xhtml-header-and-footer title))
1509       (html-mode))))
1510
1511 (defun markdown-output-standalone-p ()
1512   "Determine whether `markdown-command' output is standalone XHTML.
1513 Standalone XHTML output is identified by an occurrence of
1514 `markdown-xhtml-standalone-regexp' in the first five lines of output."
1515   (re-search-forward
1516    markdown-xhtml-standalone-regexp
1517    (save-excursion (goto-line 5) (point)) t))
1518
1519 (defun markdown-add-xhtml-header-and-footer (title)
1520   "Wrap XHTML header and footer with given TITLE around current buffer."
1521   (insert "<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\n"
1522           "<!DOCTYPE html PUBLIC \"-//W3C//DTD XHTML 1.0 Strict//EN\"\n"
1523           "\t\"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd\">\n\n"
1524           "<html xmlns=\"http://www.w3.org/1999/xhtml\">\n\n"
1525           "<head>\n<title>")
1526   (insert title)
1527   (insert "</title>\n")
1528   (if (> (length markdown-css-path) 0)
1529       (insert "<link rel=\"stylesheet\" type=\"text/css\" media=\"all\" href=\""
1530               markdown-css-path
1531               "\"  />\n"))
1532   (when (> (length markdown-xhtml-header-content) 0)
1533     (insert markdown-xhtml-header-content))
1534   (insert "\n</head>\n\n"
1535           "<body>\n\n")
1536   (goto-char (point-max))
1537   (insert "\n"
1538           "</body>\n"
1539           "</html>\n"))
1540
1541 (defun markdown-preview ()
1542   "Run `markdown' on the current buffer and preview the output in a browser."
1543   (interactive)
1544   (markdown markdown-output-buffer-name)
1545   (browse-url-of-buffer markdown-output-buffer-name))
1546
1547 (defun markdown-export-file-name ()
1548   "Attempt to generate a filename for Markdown output.
1549 If the current buffer is visiting a file, we construct a new
1550 output filename based on that filename.  Otherwise, return nil."
1551   (when (buffer-file-name)
1552     (concat (file-name-sans-extension (buffer-file-name)) ".html")))
1553
1554 (defun markdown-export ()
1555   "Run Markdown on the current buffer, save to a file, and return the filename.
1556 The resulting filename will be constructed using the current filename, but
1557 with the extension removed and replaced with .html."
1558   (interactive)
1559   (let ((output-file (markdown-export-file-name))
1560         (output-buffer-name))
1561     (when output-file
1562       (setq output-buffer-name (buffer-name (find-file-noselect output-file)))
1563       (markdown output-buffer-name)
1564       (with-current-buffer output-buffer-name
1565         (save-buffer)
1566         (kill-buffer-and-window))
1567       output-file)))
1568
1569 (defun markdown-export-and-view ()
1570   "Export to XHTML using `markdown-export' and browse the resulting file."
1571   (interactive)
1572   (browse-url (markdown-export)))
1573
1574 ;;; WikiLink Following/Markup ========================================================
1575
1576 (require 'thingatpt)
1577
1578 (defun markdown-wiki-link-p ()
1579   "Return non-nil when `point' is at a true wiki link.
1580 A true wiki link name matches `markdown-regex-wiki-link' but does not
1581 match the current file name after conversion This modifies the data
1582 returned by `match-data'.
1583
1584 If optional argument SHORTCUT is non-nil, we assume that
1585 `markdown-regex-wiki-link' has just been searched for.  Note that the
1586 potential wiki link name must be available via `match-string'."
1587   (let ((case-fold-search nil))
1588     (and (thing-at-point-looking-at markdown-regex-wiki-link)
1589          (or (not buffer-file-name)
1590              (not (string-equal (buffer-file-name)
1591                                 (markdown-convert-wiki-link-to-filename
1592                                  (match-string 1)))))
1593          (not (save-match-data
1594                 (save-excursion))))))
1595
1596 (defun markdown-convert-wiki-link-to-filename (name)
1597   "Generate a filename from the wiki link NAME.
1598 Spaces are converted to underscores, following the convention
1599 used by the Python Markdown WikiLinks extension."
1600   (let ((new-ext (file-name-extension (buffer-file-name)))
1601         (new-basename (replace-regexp-in-string "[[:space:]\n]" "_" name)))
1602     (concat new-basename "." new-ext)))
1603
1604 (defun markdown-follow-wiki-link (name)
1605   "Follow the wiki link NAME.
1606 Convert the name to a file name and call `find-file'.  Ensure that
1607 the new buffer remains in `markdown-mode'."
1608   (let ((filename (markdown-convert-wiki-link-to-filename name)))
1609     (find-file filename))
1610   (markdown-mode))
1611
1612 (defun markdown-follow-wiki-link-at-point ()
1613   "Find Wiki Link at point.
1614 See `markdown-wiki-link-p' and `markdown-follow-wiki-link'."
1615   (interactive)
1616   (if (markdown-wiki-link-p)
1617       (markdown-follow-wiki-link (match-string 1))
1618     (error "Point is not at a Wiki Link")))
1619
1620 (defun markdown-next-wiki-link ()
1621   "Jump to next wiki link.
1622 See `markdown-wiki-link-p'."
1623   (interactive)
1624   (if (markdown-wiki-link-p)
1625       ; At a wiki link already, move past it.
1626       (goto-char (+ 1 (match-end 0))))
1627   (save-match-data
1628     ; Search for the next wiki link and move to the beginning.
1629     (re-search-forward markdown-regex-wiki-link nil t)
1630     (goto-char (match-beginning 0))))
1631
1632 (defun markdown-previous-wiki-link ()
1633   "Jump to previous wiki link.
1634 See `markdown-wiki-link-p'."
1635   (interactive)
1636   (re-search-backward markdown-regex-wiki-link nil t))
1637
1638 (defun markdown-highlight-wiki-link (from to face)
1639   "Highlight the wiki link in the region between FROM and TO using FACE."
1640   (let ((ov (make-overlay from to)))
1641     (overlay-put ov 'face face)))
1642
1643 (defun markdown-unfontify-region-wiki-links (from to)
1644   "Remove wiki link faces from the region specified by FROM and TO."
1645   (interactive "nfrom: \nnto: ")
1646   (remove-overlays from to 'face markdown-link-face)
1647   (remove-overlays from to 'face markdown-missing-link-face))
1648
1649 (defun markdown-fontify-region-wiki-links (from to)
1650   "Search region given by FROM and TO for wiki links and fontify them.
1651 If a wiki link is found check to see if the backing file exists
1652 and highlight accordingly."
1653   (goto-char from)
1654   (while (re-search-forward markdown-regex-wiki-link to t)
1655     (let ((highlight-beginning (match-beginning 0))
1656           (highlight-end (match-end 0))
1657           (file-name
1658            (markdown-convert-wiki-link-to-filename (match-string 1))))
1659       (if (file-exists-p file-name)
1660           (markdown-highlight-wiki-link
1661            highlight-beginning highlight-end markdown-link-face)
1662         (markdown-highlight-wiki-link
1663          highlight-beginning highlight-end markdown-missing-link-face)))))
1664
1665 (defun markdown-extend-changed-region (from to)
1666   "Extend region given by FROM and TO so that we can fontify all links.
1667 The region is extended to the first newline before and the first
1668 newline after."
1669   ;; start looking for the first new line before 'from
1670   (goto-char from)
1671   (re-search-backward "\n" nil t)
1672   (let ((new-from (point-min))
1673         (new-to (point-max)))
1674     (if (not (= (point) from))
1675         (setq new-from (point)))
1676     ;; do the same thing for the first new line after 'to
1677     (goto-char to)
1678     (re-search-forward "\n" nil t)
1679     (if (not (= (point) to))
1680         (setq new-to (point)))
1681     (list new-from new-to)))
1682
1683 (defun markdown-check-change-for-wiki-link (from to change)
1684   "Check region between FROM and TO for wiki links and re-fontfy as needed.
1685 Designed to be used with the `after-change-functions' hook.
1686 CHANGE is the number of bytes of pre-change text replaced by the
1687 given range."
1688   (interactive "nfrom: \nnto: \nnchange: ")
1689   (let* ((inhibit-point-motion-hooks t)
1690          (inhibit-quit t)
1691          (modified (buffer-modified-p))
1692          (buffer-undo-list t)
1693          (inhibit-read-only t)
1694          (inhibit-point-motion-hooks t)
1695          (inhibit-modification-hooks t)
1696          (current-point (point))
1697          deactivate-mark)
1698     (unwind-protect
1699         (save-restriction
1700           ;; Extend the region to fontify so that it starts
1701           ;; and ends at safe places.
1702           (multiple-value-bind (new-from new-to)
1703               (markdown-extend-changed-region from to)
1704             ;; Unfontify existing fontification (start from scratch)
1705             (markdown-unfontify-region-wiki-links new-from new-to)
1706             ;; Now do the fontification.
1707             (markdown-fontify-region-wiki-links new-from new-to)))
1708       (unless modified
1709         (restore-buffer-modified-p nil)))
1710     (goto-char current-point)))
1711
1712 (defun markdown-fontify-buffer-wiki-links ()
1713   "Refontify all wiki links in the buffer."
1714   (interactive)
1715   (markdown-check-change-for-wiki-link (point-min) (point-max) 0))
1716
1717 ;;; Miscellaneous =============================================================
1718
1719 (defun markdown-line-number-at-pos (&optional pos)
1720   "Return (narrowed) buffer line number at position POS.
1721 If POS is nil, use current buffer location.
1722 This is an exact copy of `line-number-at-pos' for use in emacs21."
1723   (let ((opoint (or pos (point))) start)
1724     (save-excursion
1725       (goto-char (point-min))
1726       (setq start (point))
1727       (goto-char opoint)
1728       (forward-line 0)
1729       (1+ (count-lines start (point))))))
1730
1731 (defun markdown-nobreak-p ()
1732   "Return nil if it is acceptable to break the current line at the point."
1733   ;; inside in square brackets (e.g., link anchor text)
1734   (looking-back "\\[[^]]*"))
1735
1736 \f
1737
1738 ;;; Mode definition  ==========================================================
1739
1740 (defun markdown-show-version ()
1741   "Show the version number in the minibuffer."
1742   (interactive)
1743   (message "markdown-mode, version %s" markdown-mode-version))
1744
1745 ;;;###autoload
1746 (define-derived-mode markdown-mode text-mode "Markdown"
1747   "Major mode for editing Markdown files."
1748   ;; Natural Markdown tab width
1749   (setq tab-width 4)
1750   ;; Comments
1751   (make-local-variable 'comment-start)
1752   (setq comment-start "<!-- ")
1753   (make-local-variable 'comment-end)
1754   (setq comment-end " -->")
1755   (make-local-variable 'comment-start-skip)
1756   (setq comment-start-skip "<!--[ \t]*")
1757   (make-local-variable 'comment-column)
1758   (setq comment-column 0)
1759   ;; Font lock.
1760   (set (make-local-variable 'font-lock-defaults)
1761        '(markdown-mode-font-lock-keywords))
1762   (set (make-local-variable 'font-lock-multiline) t)
1763   ;; For menu support in XEmacs
1764   (easy-menu-add markdown-mode-menu markdown-mode-map)
1765   ;; Make filling work with lists (unordered, ordered, and definition)
1766   (set (make-local-variable 'paragraph-start)
1767        "\f\\|[ \t]*$\\|^[ \t]*[*+-] \\|^[ \t*][0-9]+\\.\\|^[ \t]*: ")
1768   ;; Outline mode
1769   (make-local-variable 'outline-regexp)
1770   (setq outline-regexp "#+")
1771   ;; Cause use of ellipses for invisible text.
1772   (add-to-invisibility-spec '(outline . t))
1773   ;; Indentation and filling
1774   (make-local-variable 'fill-nobreak-predicate)
1775   (add-hook 'fill-nobreak-predicate 'markdown-nobreak-p)
1776   (setq indent-line-function markdown-indent-function)
1777
1778   ;; Prepare hooks for XEmacs compatibility
1779   (when (featurep 'xemacs)
1780       (make-local-hook 'after-change-functions)
1781       (make-local-hook 'window-configuration-change-hook))
1782
1783   ;; Anytime text changes make sure it gets fontified correctly
1784   (add-hook 'after-change-functions 'markdown-check-change-for-wiki-link t t)
1785
1786   ;; If we left the buffer there is a really good chance we were
1787   ;; creating one of the wiki link documents. Make sure we get
1788   ;; refontified when we come back.
1789   (add-hook 'window-configuration-change-hook
1790             'markdown-fontify-buffer-wiki-links t t)
1791
1792   ;; do the initial link fontification
1793   (markdown-fontify-buffer-wiki-links))
1794
1795 ;(add-to-list 'auto-mode-alist '("\\.text$" . markdown-mode))
1796
1797 ;;; GitHub Flavored Markdown Mode  ============================================
1798
1799 (define-derived-mode gfm-mode markdown-mode "GFM"
1800   "Major mode for editing GitHub Flavored Markdown files."
1801   (auto-fill-mode 0)
1802   (longlines-mode 1))
1803
1804 (provide 'markdown-mode)
1805
1806 ;;; markdown-mode.el ends here