Skip to content
This repository

HTTPS clone URL

Subversion checkout URL

You can clone with HTTPS or Subversion.

Download ZIP
tree: 4fb12ff942
Fetching contributors…

Cannot retrieve contributors at this time

file 394 lines (332 sloc) 14.681 kb
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394
;;; yaml-mode.el --- Major mode for editing YAML files

;; Copyright (C) 2006 Yoshiki Kurihara

;; Author: Yoshiki Kurihara <kurihara@cpan.org>
;; Marshall T. Vandegrift <llasram@gmail.com>
;; Keywords: data yaml
;; Version: 0.0.3

;; This file is not part of Emacs

;; This file is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.

;; This file is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING. If not, write to
;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;; This is a major mode for editing files in the YAML data
;; serialization format. It was initially developed by Yoshiki
;; Kurihara and many features were added by Marshall Vandegrift. As
;; YAML and Python share the fact that indentation determines
;; structure, this mode provides indentation and indentation command
;; behavior very similar to that of python-mode.

;;; Installation:

;; To install, just drop this file into a directory in your
;; `load-path' and (optionally) byte-compile it. To automatically
;; handle files ending in '.yml', add something like:
;;
;; (require 'yaml-mode)
;; (add-to-list 'auto-mode-alist '("\\.yml$" . yaml-mode))
;;
;; to your .emacs file.
;;
;; Unlike python-mode, this mode follows the Emacs convention of not
;; binding the ENTER key to `newline-and-indent'. To get this
;; behavior, add the key definition to `yaml-mode-hook':
;;
;; (add-hook 'yaml-mode-hook
;; '(lambda ()
;; (define-key yaml-mode-map "\C-m" 'newline-and-indent)))

;;; Known Bugs:

;; YAML is easy to write but complex to parse, and this mode doesn't
;; even really try. Indentation and highlighting will break on
;; abnormally complicated structures.

;;; Code:


;; User definable variables

(defgroup yaml nil
  "Support for the YAML serialization format"
  :group 'languages
  :prefix "yaml-")

(defcustom yaml-mode-hook nil
  "*Hook run by `yaml-mode'."
  :type 'hook
  :group 'yaml)

(defcustom yaml-indent-offset 2
  "*Amount of offset per level of indentation."
  :type 'integer
  :group 'yaml)

(defcustom yaml-backspace-function 'backward-delete-char-untabify
  "*Function called by `yaml-electric-backspace' when deleting backwards."
  :type 'function
  :group 'yaml)

(defcustom yaml-block-literal-search-lines 100
  "*Maximum number of lines to search for start of block literals."
  :type 'integer
  :group 'yaml)

(defcustom yaml-block-literal-electric-alist
  '((?| . "") (?> . "-"))
  "*Characters for which to provide electric behavior.
The association list key should be a key code and the associated value
should be a string containing additional characters to insert when
that key is pressed to begin a block literal."
  :type 'alist
  :group 'yaml)

(defface yaml-tab-face
   '((((class color)) (:background "red" :foreground "red" :bold t))
     (t (:reverse-video t)))
  "Face to use for highlighting tabs in YAML files."
  :group 'faces
  :group 'yaml)


;; Constants

(defconst yaml-mode-version "0.0.3" "Version of `yaml-mode.'")

(defconst yaml-blank-line-re "^ *$"
  "Regexp matching a line containing only (valid) whitespace.")

(defconst yaml-comment-re "\\(#+.*\\)"
  "Regexp matching a line containing a YAML comment or delimiter.")

(defconst yaml-directive-re "^\\(?:--- \\)? *%\\(\\w+\\)"
  "Regexp matching a line contatining a YAML directive.")

(defconst yaml-document-delimiter-re "^ *\\(?:---\\|[.][.][.]\\)"
  "Rexexp matching a YAML document delimiter line.")

(defconst yaml-node-anchor-alias-re "[&*]\\w+"
  "Regexp matching a YAML node anchor or alias.")

(defconst yaml-tag-re "!!?[^ \n]+"
  "Rexexp matching a YAML tag.")

(defconst yaml-bare-scalar-re
  "\\(?:[^-:,#!\n{\\[ ]\\|[^#!\n{\\[ ]\\S-\\)[^#\n]*?"
  "Rexexp matching a YAML bare scalar.")

(defconst yaml-hash-key-re
  (concat "\\(?:^\\(?:--- \\)?\\|{\\|\\(?:[-,] +\\)+\\) *"
          "\\(?:" yaml-tag-re " +\\)?"
          "\\(" yaml-bare-scalar-re "\\) *:"
          "\\(?: +\\|$\\)")
  "Regexp matching a single YAML hash key.")

(defconst yaml-scalar-context-re
  (concat "\\(?:^\\(?:--- \\)?\\|{\\|\\(?:[-,] +\\)+\\) *"
          "\\(?:" yaml-bare-scalar-re " *: \\)?")
  "Regexp indicating the begininng of a scalar context.")

(defconst yaml-nested-map-re
  (concat ".*: *\\(?:&.*\\|{ *\\|" yaml-tag-re " *\\)?$")
  "Regexp matching a line beginning a YAML nested structure.")

(defconst yaml-block-literal-base-re " *[>|][-+0-9]* *\\(?:\n\\|\\'\\)"
  "Regexp matching the substring start of a block literal.")

(defconst yaml-block-literal-re
  (concat yaml-scalar-context-re
          "\\(?:" yaml-tag-re "\\)?"
          yaml-block-literal-base-re)
  "Regexp matching a line beginning a YAML block literal")

(defconst yaml-nested-sequence-re
  (concat "^\\(?: *- +\\)+"
          "\\(?:" yaml-bare-scalar-re " *:\\(?: +.*\\)?\\)?$")
  "Regexp matching a line containing one or more nested YAML sequences")

(defconst yaml-constant-scalars-re
  (concat "\\(?:^\\|\\(?::\\|-\\|,\\|{\\|\\[\\) +\\) *"
          (regexp-opt
           '("~" "null" "Null" "NULL"
             ".nan" ".NaN" ".NAN"
             ".inf" ".Inf" ".INF"
             "-.inf" "-.Inf" "-.INF"
             "y" "Y" "yes" "Yes" "YES" "n" "N" "no" "No" "NO"
             "true" "True" "TRUE" "false" "False" "FALSE"
             "on" "On" "ON" "off" "Off" "OFF") t)
          " *$")
  "Regexp matching certain scalar constants in scalar context")


;; Mode setup

(defvar yaml-mode-map ()
  "Keymap used in `yaml-mode' buffers.")
(if yaml-mode-map
    nil
  (setq yaml-mode-map (make-sparse-keymap))
  (define-key yaml-mode-map "|" 'yaml-electric-bar-and-angle)
  (define-key yaml-mode-map ">" 'yaml-electric-bar-and-angle)
  (define-key yaml-mode-map "-" 'yaml-electric-dash-and-dot)
  (define-key yaml-mode-map "." 'yaml-electric-dash-and-dot)
  (define-key yaml-mode-map [backspace] 'yaml-electric-backspace)
  (define-key yaml-mode-map "\C-j" 'newline-and-indent))

(defvar yaml-mode-syntax-table nil
  "Syntax table in use in yaml-mode buffers.")
(if yaml-mode-syntax-table
    nil
  (setq yaml-mode-syntax-table (make-syntax-table))
  (modify-syntax-entry ?\' "\"" yaml-mode-syntax-table)
  (modify-syntax-entry ?\" "\"" yaml-mode-syntax-table)
  (modify-syntax-entry ?# "<" yaml-mode-syntax-table)
  (modify-syntax-entry ?\n ">" yaml-mode-syntax-table)
  (modify-syntax-entry ?\\ "\\" yaml-mode-syntax-table)
  (modify-syntax-entry ?- "." yaml-mode-syntax-table)
  (modify-syntax-entry ?_ "_" yaml-mode-syntax-table)
  (modify-syntax-entry ?\( "." yaml-mode-syntax-table)
  (modify-syntax-entry ?\) "." yaml-mode-syntax-table)
  (modify-syntax-entry ?\{ "(}" yaml-mode-syntax-table)
  (modify-syntax-entry ?\} "){" yaml-mode-syntax-table)
  (modify-syntax-entry ?\[ "(]" yaml-mode-syntax-table)
  (modify-syntax-entry ?\] ")[" yaml-mode-syntax-table))

(define-derived-mode yaml-mode fundamental-mode "YAML"
  "Simple mode to edit YAML.

\\{yaml-mode-map}"
  (set (make-local-variable 'comment-start) "# ")
  (set (make-local-variable 'comment-start-skip) "#+ *")
  (set (make-local-variable 'indent-line-function) 'yaml-indent-line)
  (set (make-local-variable 'font-lock-defaults)
       '(yaml-font-lock-keywords
         nil nil nil nil
         (font-lock-syntactic-keywords . yaml-font-lock-syntactic-keywords)))
  ;; TABs are not allowed in YAML
  (set (make-local-variable 'indent-tabs-mode) nil))


;; Font-lock support

(defvar yaml-font-lock-keywords
   (list
    (cons yaml-comment-re '(1 font-lock-comment-face))
    (cons yaml-constant-scalars-re '(1 font-lock-constant-face))
    (cons yaml-tag-re '(0 font-lock-type-face))
    (cons yaml-node-anchor-alias-re '(0 font-lock-function-name-face t))
    (cons yaml-hash-key-re '(1 font-lock-variable-name-face t))
    (cons yaml-document-delimiter-re '(0 font-lock-comment-face))
    (cons yaml-directive-re '(1 font-lock-builtin-face))
    '(yaml-font-lock-block-literals 0 font-lock-string-face t)
    '("^[\t]+" 0 'yaml-tab-face t))
   "Additional expressions to highlight in YAML mode.")

(defvar yaml-font-lock-syntactic-keywords
  (list '(yaml-syntactic-block-literals 0 "." t))
  "Additional syntax features to highlight in YAML mode.")


(defun yaml-font-lock-block-literals (bound)
  "Find lines within block literals.
Find the next line of the first (if any) block literal after point and
prior to BOUND. Returns the beginning and end of the block literal
line in the match data, as consumed by `font-lock-keywords' matcher
functions. The function begins by searching backwards to determine
whether or not the current line is within a block literal. This could
be time-consuming in large buffers, so the number of lines searched is
artificially limitted to the value of
`yaml-block-literal-search-lines'."
  (if (eolp) (goto-char (1+ (point))))
  (unless (or (eobp) (>= (point) bound))
    (let ((begin (point))
          (end (min (1+ (point-at-eol)) bound)))
      (goto-char (point-at-bol))
      (while (and (looking-at yaml-blank-line-re) (not (bobp)))
        (forward-line -1))
      (let ((nlines yaml-block-literal-search-lines)
            (min-level (current-indentation)))
      (forward-line -1)
      (while (and (/= nlines 0)
                  (/= min-level 0)
                  (not (looking-at yaml-block-literal-re))
                  (not (bobp)))
        (set 'nlines (1- nlines))
        (unless (looking-at yaml-blank-line-re)
          (set 'min-level (min min-level (current-indentation))))
        (forward-line -1))
      (cond
       ((and (< (current-indentation) min-level)
             (looking-at yaml-block-literal-re))
          (goto-char end) (set-match-data (list begin end)) t)
         ((progn
            (goto-char begin)
            (re-search-forward (concat yaml-block-literal-re
                                       " *\\(.*\\)\n")
                               bound t))
          (set-match-data (nthcdr 2 (match-data))) t))))))

(defun yaml-syntactic-block-literals (bound)
  "Find quote characters within block literals.
Finds the first quote character within a block literal (if any) after
point and prior to BOUND. Returns the position of the quote character
in the match data, as consumed by matcher functions in
`font-lock-syntactic-keywords'. This allows the mode to treat ['\"]
characters in block literals as punctuation syntax instead of string
syntax, preventing unmatched quotes in block literals from painting
the entire buffer in `font-lock-string-face'."
  (let ((found nil))
    (while (and (not found)
                (/= (point) bound)
                (yaml-font-lock-block-literals bound))
      (let ((begin (match-beginning 0)) (end (match-end 0)))
        (goto-char begin)
        (cond
         ((re-search-forward "['\"]" end t) (setq found t))
         ((goto-char end)))))
    found))


;; Indentation and electric keys

(defun yaml-compute-indentation ()
  "Calculate the maximum sensible indentation for the current line."
  (save-excursion
    (beginning-of-line)
    (if (looking-at yaml-document-delimiter-re) 0
      (forward-line -1)
      (while (and (looking-at yaml-blank-line-re)
                  (> (point) (point-min)))
        (forward-line -1))
      (+ (current-indentation)
         (if (looking-at yaml-nested-map-re) yaml-indent-offset 0)
         (if (looking-at yaml-nested-sequence-re) yaml-indent-offset 0)
         (if (looking-at yaml-block-literal-re) yaml-indent-offset 0)))))

(defun yaml-indent-line ()
  "Indent the current line.
The first time this command is used, the line will be indented to the
maximum sensible indentation. Each immediately subsequent usage will
back-dent the line by `yaml-indent-offset' spaces. On reaching column
0, it will cycle back to the maximum sensible indentation."
  (interactive "*")
  (let ((ci (current-indentation))
        (cc (current-column))
        (need (yaml-compute-indentation)))
    (save-excursion
      (beginning-of-line)
      (delete-horizontal-space)
      (if (and (equal last-command this-command) (/= ci 0))
          (indent-to (* (/ (- ci 1) yaml-indent-offset) yaml-indent-offset))
        (indent-to need)))
      (if (< (current-column) (current-indentation))
          (forward-to-indentation 0))))

(defun yaml-electric-backspace (arg)
  "Delete characters or back-dent the current line.
If invoked following only whitespace on a line, will back-dent to the
immediately previous multiple of `yaml-indent-offset' spaces."
  (interactive "*p")
  (if (or (/= (current-indentation) (current-column)) (bolp))
      (funcall yaml-backspace-function arg)
    (let ((ci (current-column)))
      (beginning-of-line)
      (delete-horizontal-space)
      (indent-to (* (/ (- ci (* arg yaml-indent-offset))
                       yaml-indent-offset)
                    yaml-indent-offset)))))
  
(defun yaml-electric-bar-and-angle (arg)
  "Insert the bound key and possibly begin a block literal.
Inserts the bound key. If inserting the bound key causes the current
line to match the initial line of a block literal, then inserts the
matching string from `yaml-block-literal-electric-alist', a newline,
and indents appropriately."
  (interactive "*P")
  (self-insert-command (prefix-numeric-value arg))
  (let ((extra-chars
         (assoc last-command-char
                yaml-block-literal-electric-alist)))
    (cond
     ((and extra-chars (not arg) (eolp)
           (save-excursion
             (beginning-of-line)
             (looking-at yaml-block-literal-re)))
      (insert (cdr extra-chars))
      (newline-and-indent)))))

(defun yaml-electric-dash-and-dot (arg)
  "Insert the bound key and possibly de-dent line.
Inserts the bound key. If inserting the bound key causes the current
line to match a document delimiter, de-dent the line to the left
margin."
  (interactive "*P")
  (self-insert-command (prefix-numeric-value arg))
  (save-excursion
    (beginning-of-line)
    (if (and (not arg) (looking-at yaml-document-delimiter-re))
        (delete-horizontal-space))))

(defun yaml-mode-version ()
  "Diplay version of `yaml-mode'."
  (interactive)
  (message "yaml-mode %s" yaml-mode-version)
  yaml-mode-version)

(provide 'yaml-mode)

;;; yaml-mode.el ends here
Something went wrong with that request. Please try again.