lisp/progmodes/ruby-mode.el

   1 ;;; ruby-mode.el --- Major mode for editing Ruby files
   2
   3 ;; Copyright (C) 1994-2013 Free Software Foundation, Inc.
   4
   5 ;; Authors: Yukihiro Matsumoto
   6 ;;      Nobuyoshi Nakada
   7 ;; URL: http://www.emacswiki.org/cgi-bin/wiki/RubyMode
   8 ;; Created: Fri Feb  4 14:49:13 JST 1994
   9 ;; Keywords: languages ruby
  10 ;; Version: 1.2
  11
  12 ;; This file is part of GNU Emacs.
  13
  14 ;; GNU Emacs is free software: you can redistribute it and/or modify
  15 ;; it under the terms of the GNU General Public License as published by
  16 ;; the Free Software Foundation, either version 3 of the License, or
  17 ;; (at your option) any later version.
  18
  19 ;; GNU Emacs is distributed in the hope that it will be useful,
  20 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 ;; GNU General Public License for more details.
  23
  24 ;; You should have received a copy of the GNU General Public License
  25 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  26
  27 ;;; Commentary:
  28
  29 ;; Provides font-locking, indentation support, and navigation for Ruby code.
  30 ;;
  31 ;; If you're installing manually, you should add this to your .emacs
  32 ;; file after putting it on your load path:
  33 ;;
  34 ;;    (autoload 'ruby-mode "ruby-mode" "Major mode for ruby files" t)
  35 ;;    (add-to-list 'auto-mode-alist '("\\.rb$" . ruby-mode))
  36 ;;    (add-to-list 'interpreter-mode-alist '("ruby" . ruby-mode))
  37 ;;
  38 ;; Still needs more docstrings; search below for TODO.
  39
  40 ;;; Code:
  41
  42 (eval-when-compile (require 'cl))
  43
  44 (defgroup ruby nil
  45   "Major mode for editing Ruby code."
  46   :prefix "ruby-"
  47   :group 'languages)
  48
  49 (defconst ruby-block-beg-keywords
  50   '("class" "module" "def" "if" "unless" "case" "while" "until" "for" "begin" "do")
  51   "Keywords at the beginning of blocks.")
  52
  53 (defconst ruby-block-beg-re
  54   (regexp-opt ruby-block-beg-keywords)
  55   "Regexp to match the beginning of blocks.")
  56
  57 (defconst ruby-non-block-do-re
  58   (regexp-opt '("while" "until" "for" "rescue") 'symbols)
  59   "Regexp to match keywords that nest without blocks.")
  60
  61 (defconst ruby-indent-beg-re
  62   (concat "^\\(\\s *" (regexp-opt '("class" "module" "def")) "\\|"
  63           (regexp-opt '("if" "unless" "case" "while" "until" "for" "begin"))
  64           "\\)\\_>")
  65   "Regexp to match where the indentation gets deeper.")
  66
  67 (defconst ruby-modifier-beg-keywords
  68   '("if" "unless" "while" "until")
  69   "Modifiers that are the same as the beginning of blocks.")
  70
  71 (defconst ruby-modifier-beg-re
  72   (regexp-opt ruby-modifier-beg-keywords)
  73   "Regexp to match modifiers same as the beginning of blocks.")
  74
  75 (defconst ruby-modifier-re
  76   (regexp-opt (cons "rescue" ruby-modifier-beg-keywords))
  77   "Regexp to match modifiers.")
  78
  79 (defconst ruby-block-mid-keywords
  80   '("then" "else" "elsif" "when" "rescue" "ensure")
  81   "Keywords where the indentation gets shallower in middle of block statements.")
  82
  83 (defconst ruby-block-mid-re
  84   (regexp-opt ruby-block-mid-keywords)
  85   "Regexp to match where the indentation gets shallower in middle of block statements.")
  86
  87 (defconst ruby-block-op-keywords
  88   '("and" "or" "not")
  89   "Regexp to match boolean keywords.")
  90
  91 (defconst ruby-block-hanging-re
  92   (regexp-opt (append ruby-modifier-beg-keywords ruby-block-op-keywords))
  93   "Regexp to match hanging block modifiers.")
  94
  95 (defconst ruby-block-end-re "\\_<end\\_>")
  96
  97 (defconst ruby-defun-beg-re
  98   '"\\(def\\|class\\|module\\)"
  99   "Regexp to match the beginning of a defun, in the general sense.")
 100
 101 (defconst ruby-singleton-class-re
 102   "class\\s *<<"
 103   "Regexp to match the beginning of a singleton class context.")
 104
 105 (eval-and-compile
 106   (defconst ruby-here-doc-beg-re
 107   "\\(<\\)<\\(-\\)?\\(\\([a-zA-Z0-9_]+\\)\\|[\"]\\([^\"]+\\)[\"]\\|[']\\([^']+\\)[']\\)"
 108   "Regexp to match the beginning of a heredoc.")
 109
 110   (defconst ruby-expression-expansion-re
 111     "\\(?:[^\\]\\|\\=\\)\\(\\\\\\\\\\)*\\(#\\({[^}\n\\\\]*\\(\\\\.[^}\n\\\\]*\\)*}\\|\\(\\$\\|@\\|@@\\)\\(\\w\\|_\\)+\\)\\)"))
 112
 113 (defun ruby-here-doc-end-match ()
 114   "Return a regexp to find the end of a heredoc.
 115
 116 This should only be called after matching against `ruby-here-doc-beg-re'."
 117   (concat "^"
 118           (if (match-string 2) "[ \t]*" nil)
 119           (regexp-quote
 120            (or (match-string 4)
 121                (match-string 5)
 122                (match-string 6)))))
 123
 124 (defconst ruby-delimiter
 125   (concat "[?$/%(){}#\"'`.:]\\|<<\\|\\[\\|\\]\\|\\_<\\("
 126           ruby-block-beg-re
 127           "\\)\\_>\\|" ruby-block-end-re
 128           "\\|^=begin\\|" ruby-here-doc-beg-re))
 129
 130 (defconst ruby-negative
 131   (concat "^[ \t]*\\(\\(" ruby-block-mid-re "\\)\\>\\|"
 132           ruby-block-end-re "\\|}\\|\\]\\)")
 133   "Regexp to match where the indentation gets shallower.")
 134
 135 (defconst ruby-operator-re "[-,.+*/%&|^~=<>:]\\|\\\\$"
 136   "Regexp to match operators.")
 137
 138 (defconst ruby-symbol-chars "a-zA-Z0-9_"
 139   "List of characters that symbol names may contain.")
 140
 141 (defconst ruby-symbol-re (concat "[" ruby-symbol-chars "]")
 142   "Regexp to match symbols.")
 143
 144 (define-abbrev-table 'ruby-mode-abbrev-table ()
 145   "Abbrev table in use in Ruby mode buffers.")
 146
 147 (defvar ruby-use-smie nil)
 148
 149 (defvar ruby-mode-map
 150   (let ((map (make-sparse-keymap)))
 151     (unless ruby-use-smie
 152       (define-key map (kbd "M-C-b") 'ruby-backward-sexp)
 153       (define-key map (kbd "M-C-f") 'ruby-forward-sexp)
 154       (define-key map (kbd "M-C-q") 'ruby-indent-exp))
 155     (define-key map (kbd "M-C-p") 'ruby-beginning-of-block)
 156     (define-key map (kbd "M-C-n") 'ruby-end-of-block)
 157     (define-key map (kbd "C-c {") 'ruby-toggle-block)
 158     map)
 159   "Keymap used in Ruby mode.")
 160
 161 (defvar ruby-mode-syntax-table
 162   (let ((table (make-syntax-table)))
 163     (modify-syntax-entry ?\' "\"" table)
 164     (modify-syntax-entry ?\" "\"" table)
 165     (modify-syntax-entry ?\` "\"" table)
 166     (modify-syntax-entry ?# "<" table)
 167     (modify-syntax-entry ?\n ">" table)
 168     (modify-syntax-entry ?\\ "\\" table)
 169     (modify-syntax-entry ?$ "." table)
 170     (modify-syntax-entry ?? "_" table)
 171     (modify-syntax-entry ?_ "_" table)
 172     (modify-syntax-entry ?: "_" table)
 173     (modify-syntax-entry ?< "." table)
 174     (modify-syntax-entry ?> "." table)
 175     (modify-syntax-entry ?& "." table)
 176     (modify-syntax-entry ?| "." table)
 177     (modify-syntax-entry ?% "." table)
 178     (modify-syntax-entry ?= "." table)
 179     (modify-syntax-entry ?/ "." table)
 180     (modify-syntax-entry ?+ "." table)
 181     (modify-syntax-entry ?* "." table)
 182     (modify-syntax-entry ?- "." table)
 183     (modify-syntax-entry ?\; "." table)
 184     (modify-syntax-entry ?\( "()" table)
 185     (modify-syntax-entry ?\) ")(" table)
 186     (modify-syntax-entry ?\{ "(}" table)
 187     (modify-syntax-entry ?\} "){" table)
 188     (modify-syntax-entry ?\[ "(]" table)
 189     (modify-syntax-entry ?\] ")[" table)
 190     table)
 191   "Syntax table to use in Ruby mode.")
 192
 193 (defcustom ruby-indent-tabs-mode nil
 194   "Indentation can insert tabs in Ruby mode if this is non-nil."
 195   :type 'boolean :group 'ruby)
 196
 197 (defcustom ruby-indent-level 2
 198   "Indentation of Ruby statements."
 199   :type 'integer :group 'ruby)
 200
 201 (defcustom ruby-comment-column 32
 202   "Indentation column of comments."
 203   :type 'integer :group 'ruby)
 204
 205 (defcustom ruby-deep-arglist t
 206   "Deep indent lists in parenthesis when non-nil.
 207 Also ignores spaces after parenthesis when 'space."
 208   :group 'ruby)
 209
 210 (defcustom ruby-deep-indent-paren '(?\( ?\[ ?\] t)
 211   "Deep indent lists in parenthesis when non-nil.
 212 The value t means continuous line.
 213 Also ignores spaces after parenthesis when 'space."
 214   :group 'ruby)
 215
 216 (defcustom ruby-deep-indent-paren-style 'space
 217   "Default deep indent style."
 218   :options '(t nil space) :group 'ruby)
 219
 220 (defcustom ruby-encoding-map '((shift_jis . cp932) (shift-jis . cp932))
 221   "Alist to map encoding name from Emacs to Ruby."
 222   :group 'ruby)
 223
 224 (defcustom ruby-insert-encoding-magic-comment t
 225   "Insert a magic Emacs 'coding' comment upon save if this is non-nil."
 226   :type 'boolean :group 'ruby)
 227
 228 (defcustom ruby-use-encoding-map t
 229   "Use `ruby-encoding-map' to set encoding magic comment if this is non-nil."
 230   :type 'boolean :group 'ruby)
 231
 232 ;; Safe file variables
 233 (put 'ruby-indent-tabs-mode 'safe-local-variable 'booleanp)
 234 (put 'ruby-indent-level 'safe-local-variable 'integerp)
 235 (put 'ruby-comment-column 'safe-local-variable 'integerp)
 236 (put 'ruby-deep-arglist 'safe-local-variable 'booleanp)
 237
 238 ;;; SMIE support
 239
 240 (require 'smie)
 241
 242 (defconst ruby-smie-grammar
 243   ;; FIXME: Add support for Cucumber.
 244   (smie-prec2->grammar
 245    (smie-bnf->prec2
 246     '((id)
 247       (insts (inst) (insts ";" insts))
 248       (inst (exp) (inst "iuwu-mod" exp))
 249       (exp  (exp1) (exp "," exp))
 250       (exp1 (exp2) (exp2 "?" exp1 ":" exp1))
 251       (exp2 ("def" insts "end")
 252             ("begin" insts-rescue-insts "end")
 253             ("do" insts "end")
 254             ("class" insts "end") ("module" insts "end")
 255             ("for" for-body "end")
 256             ("[" expseq "]")
 257             ("{" hashvals "}")
 258             ("{" insts "}")
 259             ("while" insts "end")
 260             ("until" insts "end")
 261             ("unless" insts "end")
 262             ("if" if-body "end")
 263             ("case"  cases "end"))
 264       (formal-params ("opening-|" exp "|"))
 265       (for-body (for-head ";" insts))
 266       (for-head (id "in" exp))
 267       (cases (exp "then" insts) ;; FIXME: Ruby also allows (exp ":" insts).
 268               (cases "when" cases) (insts "else" insts))
 269       (expseq (exp) );;(expseq "," expseq)
 270       (hashvals (id "=>" exp1) (hashvals "," hashvals))
 271       (insts-rescue-insts (insts)
 272                           (insts-rescue-insts "rescue" insts-rescue-insts)
 273                           (insts-rescue-insts "ensure" insts-rescue-insts))
 274       (itheni (insts) (exp "then" insts))
 275       (ielsei (itheni) (itheni "else" insts))
 276       (if-body (ielsei) (if-body "elsif" if-body)))
 277     '((nonassoc "in") (assoc ";") (assoc ","))
 278     '((assoc "when"))
 279     '((assoc "elsif"))
 280     '((assoc "rescue" "ensure"))
 281     '((assoc ",")))))
 282
 283 (defun ruby-smie--bosp ()
 284   (save-excursion (skip-chars-backward " \t")
 285                   (or (bolp) (eq (char-before) ?\;))))
 286
 287 (defun ruby-smie--implicit-semi-p ()
 288   (save-excursion
 289     (skip-chars-backward " \t")
 290     (not (or (bolp)
 291              (and (memq (char-before) '(?\; ?- ?+ ?* ?/ ?: ?.))
 292                   ;; Make sure it's not the end of a regexp.
 293                   (not (eq (car (syntax-after (1- (point)))) 7)))
 294              (and (memq (char-before) '(?\? ?=))
 295                   (let ((tok (ruby-smie--backward-token)))
 296                     (or (equal tok "?")
 297                         (string-match "\\`\\s." tok))))))))
 298
 299 (defun ruby-smie--opening-pipe-p ()
 300   (save-excursion
 301     (if (eq ?| (char-before)) (forward-char -1))
 302     (skip-chars-backward " \t\n")
 303     (or (eq ?\{ (char-before))
 304         (looking-back "\\_<do" (- (point) 2)))))
 305
 306 (defun ruby-smie--forward-token ()
 307   (skip-chars-forward " \t")
 308   (if (and (looking-at "[\n#]")
 309            ;; Only add implicit ; when needed.
 310            (ruby-smie--implicit-semi-p))
 311       (progn
 312         (if (eolp) (forward-char 1) (forward-comment 1))
 313         ";")
 314     (forward-comment (point-max))
 315     (if (looking-at ":\\s.+")
 316         (progn (goto-char (match-end 0)) (match-string 0)) ;; bug#15208.
 317     (let ((tok (smie-default-forward-token)))
 318       (cond
 319        ((member tok '("unless" "if" "while" "until"))
 320         (if (save-excursion (forward-word -1) (ruby-smie--bosp))
 321             tok "iuwu-mod"))
 322          ((equal tok "|")
 323           (if (ruby-smie--opening-pipe-p) "opening-|" tok))
 324          (t tok))))))
 325
 326 (defun ruby-smie--backward-token ()
 327   (let ((pos (point)))
 328     (forward-comment (- (point)))
 329     (if (and (> pos (line-end-position))
 330              (ruby-smie--implicit-semi-p))
 331         (progn (skip-chars-forward " \t")
 332                ";")
 333       (let ((tok (smie-default-backward-token)))
 334         (when (and (eq ?: (char-before)) (string-match "\\`\\s." tok))
 335           (forward-char -1) (setq tok (concat ":" tok))) ;; bug#15208.
 336         (cond
 337          ((member tok '("unless" "if" "while" "until"))
 338           (if (ruby-smie--bosp)
 339               tok "iuwu-mod"))
 340          ((equal tok "|")
 341           (if (ruby-smie--opening-pipe-p) "opening-|" tok))
 342          (t tok))))))
 343
 344 (defun ruby-smie-rules (kind token)
 345   (pcase (cons kind token)
 346     (`(:elem . basic) ruby-indent-level)
 347     (`(:after . ";")
 348      (if (smie-rule-parent-p "def" "begin" "do" "class" "module" "for"
 349                              "[" "{" "while" "until" "unless"
 350                              "if" "then" "elsif" "else" "when"
 351                              "rescue" "ensure")
 352          (smie-rule-parent ruby-indent-level)
 353        ;; For (invalid) code between switch and case.
 354        ;; (if (smie-parent-p "switch") 4)
 355        0))
 356     (`(:before . "do")
 357      (when
 358          (save-excursion
 359            (forward-word 1)   ;Skip "do"
 360            (skip-chars-forward " \t")
 361            (and (equal (save-excursion (ruby-smie--forward-token)) "opening-|")
 362                 (save-excursion (forward-sexp 1)
 363                                 (skip-chars-forward " \t")
 364                                 (or (eolp)
 365                                     (looking-at comment-start-skip)))))
 366        ;; `(column . ,(smie-indent-virtual))
 367        (smie-rule-parent)))
 368     (`(:before . ,(or `"else" `"then" `"elsif" `"rescue")) 0)
 369     (`(:before . ,(or `"when"))
 370      (if (not (smie-rule-sibling-p)) 0)) ;; ruby-indent-level
 371     ;; Hack attack: Since newlines are separators, don't try to align args that
 372     ;; appear on a separate line.
 373     (`(:list-intro . ";") t)))
 374
 375 (defun ruby-imenu-create-index-in-block (prefix beg end)
 376   "Create an imenu index of methods inside a block."
 377   (let ((index-alist '()) (case-fold-search nil)
 378         name next pos decl sing)
 379     (goto-char beg)
 380     (while (re-search-forward "^\\s *\\(\\(class\\s +\\|\\(class\\s *<<\\s *\\)\\|module\\s +\\)\\([^\(<\n ]+\\)\\|\\(def\\|alias\\)\\s +\\([^\(\n ]+\\)\\)" end t)
 381       (setq sing (match-beginning 3))
 382       (setq decl (match-string 5))
 383       (setq next (match-end 0))
 384       (setq name (or (match-string 4) (match-string 6)))
 385       (setq pos (match-beginning 0))
 386       (cond
 387        ((string= "alias" decl)
 388         (if prefix (setq name (concat prefix name)))
 389         (push (cons name pos) index-alist))
 390        ((string= "def" decl)
 391         (if prefix
 392             (setq name
 393                   (cond
 394                    ((string-match "^self\." name)
 395                     (concat (substring prefix 0 -1) (substring name 4)))
 396                   (t (concat prefix name)))))
 397         (push (cons name pos) index-alist)
 398         (ruby-accurate-end-of-block end))
 399        (t
 400         (if (string= "self" name)
 401             (if prefix (setq name (substring prefix 0 -1)))
 402           (if prefix (setq name (concat (substring prefix 0 -1) "::" name)))
 403           (push (cons name pos) index-alist))
 404         (ruby-accurate-end-of-block end)
 405         (setq beg (point))
 406         (setq index-alist
 407               (nconc (ruby-imenu-create-index-in-block
 408                       (concat name (if sing "." "#"))
 409                       next beg) index-alist))
 410         (goto-char beg))))
 411     index-alist))
 412
 413 (defun ruby-imenu-create-index ()
 414   "Create an imenu index of all methods in the buffer."
 415   (nreverse (ruby-imenu-create-index-in-block nil (point-min) nil)))
 416
 417 (defun ruby-accurate-end-of-block (&optional end)
 418   "TODO: document."
 419   (let (state
 420         (end (or end (point-max))))
 421     (while (and (setq state (apply 'ruby-parse-partial end state))
 422                 (>= (nth 2 state) 0) (< (point) end)))))
 423
 424 (defun ruby-mode-variables ()
 425   "Set up initial buffer-local variables for Ruby mode."
 426   (set-syntax-table ruby-mode-syntax-table)
 427   (setq local-abbrev-table ruby-mode-abbrev-table)
 428   (setq indent-tabs-mode ruby-indent-tabs-mode)
 429   (if ruby-use-smie
 430       (smie-setup ruby-smie-grammar #'ruby-smie-rules
 431                   :forward-token  #'ruby-smie--forward-token
 432                   :backward-token #'ruby-smie--backward-token)
 433     (set (make-local-variable 'indent-line-function) 'ruby-indent-line))
 434   (set (make-local-variable 'require-final-newline) t)
 435   (set (make-local-variable 'comment-start) "# ")
 436   (set (make-local-variable 'comment-end) "")
 437   (set (make-local-variable 'comment-column) ruby-comment-column)
 438   (set (make-local-variable 'comment-start-skip) "#+ *")
 439   (set (make-local-variable 'parse-sexp-ignore-comments) t)
 440   (set (make-local-variable 'parse-sexp-lookup-properties) t)
 441   (set (make-local-variable 'paragraph-start) (concat "$\\|" page-delimiter))
 442   (set (make-local-variable 'paragraph-separate) paragraph-start)
 443   (set (make-local-variable 'paragraph-ignore-fill-prefix) t))
 444
 445 (defun ruby-mode-set-encoding ()
 446   "Insert a magic comment header with the proper encoding if necessary."
 447   (save-excursion
 448     (widen)
 449     (goto-char (point-min))
 450     (when (re-search-forward "[^\0-\177]" nil t)
 451       (goto-char (point-min))
 452       (let ((coding-system
 453              (or coding-system-for-write
 454                  buffer-file-coding-system)))
 455         (if coding-system
 456             (setq coding-system
 457                   (or (coding-system-get coding-system 'mime-charset)
 458                       (coding-system-change-eol-conversion coding-system nil))))
 459         (setq coding-system
 460               (if coding-system
 461                   (symbol-name
 462                    (or (and ruby-use-encoding-map
 463                             (cdr (assq coding-system ruby-encoding-map)))
 464                        coding-system))
 465                 "ascii-8bit"))
 466         (if (looking-at "^#!") (beginning-of-line 2))
 467         (cond ((looking-at "\\s *#.*-\*-\\s *\\(en\\)?coding\\s *:\\s *\\([-a-z0-9_]*\\)\\s *\\(;\\|-\*-\\)")
 468                (unless (string= (match-string 2) coding-system)
 469                  (goto-char (match-beginning 2))
 470                  (delete-region (point) (match-end 2))
 471                  (and (looking-at "-\*-")
 472                       (let ((n (skip-chars-backward " ")))
 473                         (cond ((= n 0) (insert "  ") (backward-char))
 474                               ((= n -1) (insert " "))
 475                               ((forward-char)))))
 476                  (insert coding-system)))
 477               ((looking-at "\\s *#.*coding\\s *[:=]"))
 478               (t (when ruby-insert-encoding-magic-comment
 479                    (insert "# -*- coding: " coding-system " -*-\n"))))))))
 480
 481 (defun ruby-current-indentation ()
 482   "Return the indentation level of current line."
 483   (save-excursion
 484     (beginning-of-line)
 485     (back-to-indentation)
 486     (current-column)))
 487
 488 (defun ruby-indent-line (&optional ignored)
 489   "Correct the indentation of the current Ruby line."
 490   (interactive)
 491   (ruby-indent-to (ruby-calculate-indent)))
 492
 493 (defun ruby-indent-to (column)
 494   "Indent the current line to COLUMN."
 495   (when column
 496     (let (shift top beg)
 497       (and (< column 0) (error "invalid nest"))
 498       (setq shift (current-column))
 499       (beginning-of-line)
 500       (setq beg (point))
 501       (back-to-indentation)
 502       (setq top (current-column))
 503       (skip-chars-backward " \t")
 504       (if (>= shift top) (setq shift (- shift top))
 505         (setq shift 0))
 506       (if (and (bolp)
 507                (= column top))
 508           (move-to-column (+ column shift))
 509         (move-to-column top)
 510         (delete-region beg (point))
 511         (beginning-of-line)
 512         (indent-to column)
 513         (move-to-column (+ column shift))))))
 514
 515 (defun ruby-special-char-p (&optional pos)
 516   "Return t if the character before POS is a special character.
 517 If omitted, POS defaults to the current point.
 518 Special characters are `?', `$', `:' when preceded by whitespace,
 519 and `\\' when preceded by `?'."
 520   (setq pos (or pos (point)))
 521   (let ((c (char-before pos)) (b (and (< (point-min) pos)
 522                                       (char-before (1- pos)))))
 523     (cond ((or (eq c ??) (eq c ?$)))
 524           ((and (eq c ?:) (or (not b) (eq (char-syntax b) ? ))))
 525           ((eq c ?\\) (eq b ??)))))
 526
 527 (defun ruby-singleton-class-p (&optional pos)
 528   (save-excursion
 529     (when pos (goto-char pos))
 530     (forward-word -1)
 531     (and (or (bolp) (not (eq (char-before (point)) ?_)))
 532          (looking-at ruby-singleton-class-re))))
 533
 534 (defun ruby-expr-beg (&optional option)
 535   "Check if point is possibly at the beginning of an expression.
 536 OPTION specifies the type of the expression.
 537 Can be one of `heredoc', `modifier', `expr-qstr', `expr-re'."
 538   (save-excursion
 539     (store-match-data nil)
 540     (let ((space (skip-chars-backward " \t"))
 541           (start (point)))
 542       (cond
 543        ((bolp) t)
 544        ((progn
 545           (forward-char -1)
 546           (and (looking-at "\\?")
 547                (or (eq (char-syntax (char-before (point))) ?w)
 548                    (ruby-special-char-p))))
 549         nil)
 550        ((looking-at ruby-operator-re))
 551        ((eq option 'heredoc)
 552         (and (< space 0) (not (ruby-singleton-class-p start))))
 553        ((or (looking-at "[\\[({,;]")
 554             (and (looking-at "[!?]")
 555                  (or (not (eq option 'modifier))
 556                      (bolp)
 557                      (save-excursion (forward-char -1) (looking-at "\\Sw$"))))
 558             (and (looking-at ruby-symbol-re)
 559                  (skip-chars-backward ruby-symbol-chars)
 560                  (cond
 561                   ((looking-at (regexp-opt
 562                                 (append ruby-block-beg-keywords
 563                                         ruby-block-op-keywords
 564                                         ruby-block-mid-keywords)
 565                                 'words))
 566                    (goto-char (match-end 0))
 567                    (not (looking-at "\\s_\\|!")))
 568                   ((eq option 'expr-qstr)
 569                    (looking-at "[a-zA-Z][a-zA-z0-9_]* +%[^ \t]"))
 570                   ((eq option 'expr-re)
 571                    (looking-at "[a-zA-Z][a-zA-z0-9_]* +/[^ \t]"))
 572                   (t nil)))))))))
 573
 574 (defun ruby-forward-string (term &optional end no-error expand)
 575   "TODO: document."
 576   (let ((n 1) (c (string-to-char term))
 577         (re (if expand
 578                 (concat "[^\\]\\(\\\\\\\\\\)*\\([" term "]\\|\\(#{\\)\\)")
 579               (concat "[^\\]\\(\\\\\\\\\\)*[" term "]"))))
 580     (while (and (re-search-forward re end no-error)
 581                 (if (match-beginning 3)
 582                     (ruby-forward-string "}{" end no-error nil)
 583                   (> (setq n (if (eq (char-before (point)) c)
 584                                      (1- n) (1+ n))) 0)))
 585       (forward-char -1))
 586     (cond ((zerop n))
 587           (no-error nil)
 588           ((error "unterminated string")))))
 589
 590 (defun ruby-deep-indent-paren-p (c)
 591   "TODO: document."
 592   (cond ((listp ruby-deep-indent-paren)
 593          (let ((deep (assoc c ruby-deep-indent-paren)))
 594            (cond (deep
 595                   (or (cdr deep) ruby-deep-indent-paren-style))
 596                  ((memq c ruby-deep-indent-paren)
 597                   ruby-deep-indent-paren-style))))
 598         ((eq c ruby-deep-indent-paren) ruby-deep-indent-paren-style)
 599         ((eq c ?\( ) ruby-deep-arglist)))
 600
 601 (defun ruby-parse-partial (&optional end in-string nest depth pcol indent)
 602   "TODO: document throughout function body."
 603   (or depth (setq depth 0))
 604   (or indent (setq indent 0))
 605   (when (re-search-forward ruby-delimiter end 'move)
 606     (let ((pnt (point)) w re expand)
 607       (goto-char (match-beginning 0))
 608       (cond
 609        ((and (memq (char-before) '(?@ ?$)) (looking-at "\\sw"))
 610         (goto-char pnt))
 611        ((looking-at "[\"`]")            ;skip string
 612         (cond
 613          ((and (not (eobp))
 614                (ruby-forward-string (buffer-substring (point) (1+ (point))) end t t))
 615           nil)
 616          (t
 617           (setq in-string (point))
 618           (goto-char end))))
 619        ((looking-at "'")
 620         (cond
 621          ((and (not (eobp))
 622                (re-search-forward "[^\\]\\(\\\\\\\\\\)*'" end t))
 623           nil)
 624          (t
 625           (setq in-string (point))
 626           (goto-char end))))
 627        ((looking-at "/=")
 628         (goto-char pnt))
 629        ((looking-at "/")
 630         (cond
 631          ((and (not (eobp)) (ruby-expr-beg 'expr-re))
 632           (if (ruby-forward-string "/" end t t)
 633               nil
 634             (setq in-string (point))
 635             (goto-char end)))
 636          (t
 637           (goto-char pnt))))
 638        ((looking-at "%")
 639         (cond
 640          ((and (not (eobp))
 641                (ruby-expr-beg 'expr-qstr)
 642                (not (looking-at "%="))
 643                (looking-at "%[QqrxWw]?\\([^a-zA-Z0-9 \t\n]\\)"))
 644           (goto-char (match-beginning 1))
 645           (setq expand (not (memq (char-before) '(?q ?w))))
 646           (setq w (match-string 1))
 647           (cond
 648            ((string= w "[") (setq re "]["))
 649            ((string= w "{") (setq re "}{"))
 650            ((string= w "(") (setq re ")("))
 651            ((string= w "<") (setq re "><"))
 652            ((and expand (string= w "\\"))
 653             (setq w (concat "\\" w))))
 654           (unless (cond (re (ruby-forward-string re end t expand))
 655                         (expand (ruby-forward-string w end t t))
 656                         (t (re-search-forward
 657                             (if (string= w "\\")
 658                                 "\\\\[^\\]*\\\\"
 659                               (concat "[^\\]\\(\\\\\\\\\\)*" w))
 660                             end t)))
 661             (setq in-string (point))
 662             (goto-char end)))
 663          (t
 664           (goto-char pnt))))
 665        ((looking-at "\\?")              ;skip ?char
 666         (cond
 667          ((and (ruby-expr-beg)
 668                (looking-at "?\\(\\\\C-\\|\\\\M-\\)*\\\\?."))
 669           (goto-char (match-end 0)))
 670          (t
 671           (goto-char pnt))))
 672        ((looking-at "\\$")              ;skip $char
 673         (goto-char pnt)
 674         (forward-char 1))
 675        ((looking-at "#")                ;skip comment
 676         (forward-line 1)
 677         (goto-char (point))
 678         )
 679        ((looking-at "[\\[{(]")
 680         (let ((deep (ruby-deep-indent-paren-p (char-after))))
 681           (if (and deep (or (not (eq (char-after) ?\{)) (ruby-expr-beg)))
 682               (progn
 683                 (and (eq deep 'space) (looking-at ".\\s +[^# \t\n]")
 684                      (setq pnt (1- (match-end 0))))
 685                 (setq nest (cons (cons (char-after (point)) pnt) nest))
 686                 (setq pcol (cons (cons pnt depth) pcol))
 687                 (setq depth 0))
 688             (setq nest (cons (cons (char-after (point)) pnt) nest))
 689             (setq depth (1+ depth))))
 690         (goto-char pnt)
 691         )
 692        ((looking-at "[])}]")
 693         (if (ruby-deep-indent-paren-p (matching-paren (char-after)))
 694             (setq depth (cdr (car pcol)) pcol (cdr pcol))
 695           (setq depth (1- depth)))
 696         (setq nest (cdr nest))
 697         (goto-char pnt))
 698        ((looking-at ruby-block-end-re)
 699         (if (or (and (not (bolp))
 700                      (progn
 701                        (forward-char -1)
 702                        (setq w (char-after (point)))
 703                        (or (eq ?_ w)
 704                            (eq ?. w))))
 705                 (progn
 706                   (goto-char pnt)
 707                   (setq w (char-after (point)))
 708                   (or (eq ?_ w)
 709                       (eq ?! w)
 710                       (eq ?? w))))
 711             nil
 712           (setq nest (cdr nest))
 713           (setq depth (1- depth)))
 714         (goto-char pnt))
 715        ((looking-at "def\\s +[^(\n;]*")
 716         (if (or (bolp)
 717                 (progn
 718                   (forward-char -1)
 719                   (not (eq ?_ (char-after (point))))))
 720             (progn
 721               (setq nest (cons (cons nil pnt) nest))
 722               (setq depth (1+ depth))))
 723         (goto-char (match-end 0)))
 724        ((looking-at (concat "\\_<\\(" ruby-block-beg-re "\\)\\_>"))
 725         (and
 726          (save-match-data
 727            (or (not (looking-at "do\\_>"))
 728                (save-excursion
 729                  (back-to-indentation)
 730                  (not (looking-at ruby-non-block-do-re)))))
 731          (or (bolp)
 732              (progn
 733                (forward-char -1)
 734                (setq w (char-after (point)))
 735                (not (or (eq ?_ w)
 736                         (eq ?. w)))))
 737          (goto-char pnt)
 738          (not (eq ?! (char-after (point))))
 739          (skip-chars-forward " \t")
 740          (goto-char (match-beginning 0))
 741          (or (not (looking-at ruby-modifier-re))
 742              (ruby-expr-beg 'modifier))
 743          (goto-char pnt)
 744          (setq nest (cons (cons nil pnt) nest))
 745          (setq depth (1+ depth)))
 746         (goto-char pnt))
 747        ((looking-at ":\\(['\"]\\)")
 748         (goto-char (match-beginning 1))
 749         (ruby-forward-string (match-string 1) end t))
 750        ((looking-at ":\\([-,.+*/%&|^~<>]=?\\|===?\\|<=>\\|![~=]?\\)")
 751         (goto-char (match-end 0)))
 752        ((looking-at ":\\([a-zA-Z_][a-zA-Z_0-9]*[!?=]?\\)?")
 753         (goto-char (match-end 0)))
 754        ((or (looking-at "\\.\\.\\.?")
 755             (looking-at "\\.[0-9]+")
 756             (looking-at "\\.[a-zA-Z_0-9]+")
 757             (looking-at "\\."))
 758         (goto-char (match-end 0)))
 759        ((looking-at "^=begin")
 760         (if (re-search-forward "^=end" end t)
 761             (forward-line 1)
 762           (setq in-string (match-end 0))
 763           (goto-char end)))
 764        ((looking-at "<<")
 765         (cond
 766          ((and (ruby-expr-beg 'heredoc)
 767                (looking-at "<<\\(-\\)?\\(\\([\"'`]\\)\\([^\n]+?\\)\\3\\|\\(?:\\sw\\|\\s_\\)+\\)"))
 768           (setq re (regexp-quote (or (match-string 4) (match-string 2))))
 769           (if (match-beginning 1) (setq re (concat "\\s *" re)))
 770           (let* ((id-end (goto-char (match-end 0)))
 771                  (line-end-position (point-at-eol))
 772                  (state (list in-string nest depth pcol indent)))
 773             ;; parse the rest of the line
 774             (while (and (> line-end-position (point))
 775                         (setq state (apply 'ruby-parse-partial
 776                                            line-end-position state))))
 777             (setq in-string (car state)
 778                   nest (nth 1 state)
 779                   depth (nth 2 state)
 780                   pcol (nth 3 state)
 781                   indent (nth 4 state))
 782             ;; skip heredoc section
 783             (if (re-search-forward (concat "^" re "$") end 'move)
 784                 (forward-line 1)
 785               (setq in-string id-end)
 786               (goto-char end))))
 787          (t
 788           (goto-char pnt))))
 789        ((looking-at "^__END__$")
 790         (goto-char pnt))
 791        ((and (looking-at ruby-here-doc-beg-re)
 792              (boundp 'ruby-indent-point))
 793         (if (re-search-forward (ruby-here-doc-end-match)
 794                                ruby-indent-point t)
 795             (forward-line 1)
 796           (setq in-string (match-end 0))
 797           (goto-char ruby-indent-point)))
 798        (t
 799         (error (format "bad string %s"
 800                        (buffer-substring (point) pnt)
 801                        ))))))
 802   (list in-string nest depth pcol))
 803
 804 (defun ruby-parse-region (start end)
 805   "TODO: document."
 806   (let (state)
 807     (save-excursion
 808       (if start
 809           (goto-char start)
 810         (ruby-beginning-of-indent))
 811       (save-restriction
 812         (narrow-to-region (point) end)
 813         (while (and (> end (point))
 814                     (setq state (apply 'ruby-parse-partial end state))))))
 815     (list (nth 0 state)                 ; in-string
 816           (car (nth 1 state))           ; nest
 817           (nth 2 state)                 ; depth
 818           (car (car (nth 3 state)))     ; pcol
 819           ;(car (nth 5 state))          ; indent
 820           )))
 821
 822 (defun ruby-indent-size (pos nest)
 823   "Return the indentation level in spaces NEST levels deeper than POS."
 824   (+ pos (* (or nest 1) ruby-indent-level)))
 825
 826 (defun ruby-calculate-indent (&optional parse-start)
 827   "Return the proper indentation level of the current line."
 828   ;; TODO: Document body
 829   (save-excursion
 830     (beginning-of-line)
 831     (let ((ruby-indent-point (point))
 832           (case-fold-search nil)
 833           state eol begin op-end
 834           (paren (progn (skip-syntax-forward " ")
 835                         (and (char-after) (matching-paren (char-after)))))
 836           (indent 0))
 837       (if parse-start
 838           (goto-char parse-start)
 839         (ruby-beginning-of-indent)
 840         (setq parse-start (point)))
 841       (back-to-indentation)
 842       (setq indent (current-column))
 843       (setq state (ruby-parse-region parse-start ruby-indent-point))
 844       (cond
 845        ((nth 0 state)                   ; within string
 846         (setq indent nil))              ;  do nothing
 847        ((car (nth 1 state))             ; in paren
 848         (goto-char (setq begin (cdr (nth 1 state))))
 849         (let ((deep (ruby-deep-indent-paren-p (car (nth 1 state)))))
 850           (if deep
 851               (cond ((and (eq deep t) (eq (car (nth 1 state)) paren))
 852                      (skip-syntax-backward " ")
 853                      (setq indent (1- (current-column))))
 854                     ((let ((s (ruby-parse-region (point) ruby-indent-point)))
 855                        (and (nth 2 s) (> (nth 2 s) 0)
 856                             (or (goto-char (cdr (nth 1 s))) t)))
 857                      (forward-word -1)
 858                      (setq indent (ruby-indent-size (current-column)
 859                                                     (nth 2 state))))
 860                     (t
 861                      (setq indent (current-column))
 862                      (cond ((eq deep 'space))
 863                            (paren (setq indent (1- indent)))
 864                            (t (setq indent (ruby-indent-size (1- indent) 1))))))
 865             (if (nth 3 state) (goto-char (nth 3 state))
 866               (goto-char parse-start) (back-to-indentation))
 867             (setq indent (ruby-indent-size (current-column) (nth 2 state))))
 868           (and (eq (car (nth 1 state)) paren)
 869                (ruby-deep-indent-paren-p (matching-paren paren))
 870                (search-backward (char-to-string paren))
 871                (setq indent (current-column)))))
 872        ((and (nth 2 state) (> (nth 2 state) 0)) ; in nest
 873         (if (null (cdr (nth 1 state)))
 874             (error "invalid nest"))
 875         (goto-char (cdr (nth 1 state)))
 876         (forward-word -1)               ; skip back a keyword
 877         (setq begin (point))
 878         (cond
 879          ((looking-at "do\\>[^_]")      ; iter block is a special case
 880           (if (nth 3 state) (goto-char (nth 3 state))
 881             (goto-char parse-start) (back-to-indentation))
 882           (setq indent (ruby-indent-size (current-column) (nth 2 state))))
 883          (t
 884           (setq indent (+ (current-column) ruby-indent-level)))))
 885
 886        ((and (nth 2 state) (< (nth 2 state) 0)) ; in negative nest
 887         (setq indent (ruby-indent-size (current-column) (nth 2 state)))))
 888       (when indent
 889         (goto-char ruby-indent-point)
 890         (end-of-line)
 891         (setq eol (point))
 892         (beginning-of-line)
 893         (cond
 894          ((and (not (ruby-deep-indent-paren-p paren))
 895                (re-search-forward ruby-negative eol t))
 896           (and (not (eq ?_ (char-after (match-end 0))))
 897                (setq indent (- indent ruby-indent-level))))
 898          ((and
 899            (save-excursion
 900              (beginning-of-line)
 901              (not (bobp)))
 902            (or (ruby-deep-indent-paren-p t)
 903                (null (car (nth 1 state)))))
 904           ;; goto beginning of non-empty no-comment line
 905           (let (end done)
 906             (while (not done)
 907               (skip-chars-backward " \t\n")
 908               (setq end (point))
 909               (beginning-of-line)
 910               (if (re-search-forward "^\\s *#" end t)
 911                   (beginning-of-line)
 912                 (setq done t))))
 913           (end-of-line)
 914           ;; skip the comment at the end
 915           (skip-chars-backward " \t")
 916           (let (end (pos (point)))
 917             (beginning-of-line)
 918             (while (and (re-search-forward "#" pos t)
 919                         (setq end (1- (point)))
 920                         (or (ruby-special-char-p end)
 921                             (and (setq state (ruby-parse-region parse-start end))
 922                                  (nth 0 state))))
 923               (setq end nil))
 924             (goto-char (or end pos))
 925             (skip-chars-backward " \t")
 926             (setq begin (if (and end (nth 0 state)) pos (cdr (nth 1 state))))
 927             (setq state (ruby-parse-region parse-start (point))))
 928           (or (bobp) (forward-char -1))
 929           (and
 930            (or (and (looking-at ruby-symbol-re)
 931                     (skip-chars-backward ruby-symbol-chars)
 932                     (looking-at (concat "\\<\\(" ruby-block-hanging-re "\\)\\>"))
 933                     (not (eq (point) (nth 3 state)))
 934                     (save-excursion
 935                       (goto-char (match-end 0))
 936                       (not (looking-at "[a-z_]"))))
 937                (and (looking-at ruby-operator-re)
 938                     (not (ruby-special-char-p))
 939                     (save-excursion
 940                       (forward-char -1)
 941                       (or (not (looking-at ruby-operator-re))
 942                           (not (eq (char-before) ?:))))
 943                     ;; Operator at the end of line.
 944                     (let ((c (char-after (point))))
 945                       (and
 946 ;;                     (or (null begin)
 947 ;;                         (save-excursion
 948 ;;                           (goto-char begin)
 949 ;;                           (skip-chars-forward " \t")
 950 ;;                           (not (or (eolp) (looking-at "#")
 951 ;;                                    (and (eq (car (nth 1 state)) ?{)
 952 ;;                                         (looking-at "|"))))))
 953                        ;; Not a regexp or percent literal.
 954                        (null (nth 0 (ruby-parse-region (or begin parse-start)
 955                                                        (point))))
 956                        (or (not (eq ?| (char-after (point))))
 957                            (save-excursion
 958                              (or (eolp) (forward-char -1))
 959                              (cond
 960                               ((search-backward "|" nil t)
 961                                (skip-chars-backward " \t\n")
 962                                (and (not (eolp))
 963                                     (progn
 964                                       (forward-char -1)
 965                                       (not (looking-at "{")))
 966                                     (progn
 967                                       (forward-word -1)
 968                                       (not (looking-at "do\\>[^_]")))))
 969                               (t t))))
 970                        (not (eq ?, c))
 971                        (setq op-end t)))))
 972            (setq indent
 973                  (cond
 974                   ((and
 975                     (null op-end)
 976                     (not (looking-at (concat "\\<\\(" ruby-block-hanging-re "\\)\\>")))
 977                     (eq (ruby-deep-indent-paren-p t) 'space)
 978                     (not (bobp)))
 979                    (widen)
 980                    (goto-char (or begin parse-start))
 981                    (skip-syntax-forward " ")
 982                    (current-column))
 983                   ((car (nth 1 state)) indent)
 984                   (t
 985                    (+ indent ruby-indent-level))))))))
 986       (goto-char ruby-indent-point)
 987       (beginning-of-line)
 988       (skip-syntax-forward " ")
 989       (if (looking-at "\\.[^.]")
 990           (+ indent ruby-indent-level)
 991         indent))))
 992
 993 (defun ruby-beginning-of-defun (&optional arg)
 994   "Move backward to the beginning of the current defun.
 995 With ARG, move backward multiple defuns.  Negative ARG means
 996 move forward."
 997   (interactive "p")
 998   (let (case-fold-search)
 999     (and (re-search-backward (concat "^\\s *" ruby-defun-beg-re "\\_>")
1000                              nil t (or arg 1))
1001          (beginning-of-line))))
1002
1003 (defun ruby-end-of-defun ()
1004   "Move point to the end of the current defun.
1005 The defun begins at or after the point.  This function is called
1006 by `end-of-defun'."
1007   (interactive "p")
1008   (ruby-forward-sexp)
1009   (let (case-fold-search)
1010     (when (looking-back (concat "^\\s *" ruby-block-end-re))
1011       (forward-line 1))))
1012
1013 (defun ruby-beginning-of-indent ()
1014   "Backtrack to a line which can be used as a reference for
1015 calculating indentation on the lines after it."
1016   (while (and (re-search-backward ruby-indent-beg-re nil 'move)
1017               (if (ruby-in-ppss-context-p 'anything)
1018                   t
1019                 ;; We can stop, then.
1020                 (beginning-of-line)))))
1021
1022 (defun ruby-move-to-block (n)
1023   "Move to the beginning (N < 0) or the end (N > 0) of the
1024 current block, a sibling block, or an outer block.  Do that (abs N) times."
1025   (back-to-indentation)
1026   (let ((signum (if (> n 0) 1 -1))
1027         (backward (< n 0))
1028         (depth (or (nth 2 (ruby-parse-region (point) (line-end-position))) 0))
1029         case-fold-search
1030         down done)
1031     (when (looking-at ruby-block-mid-re)
1032       (setq depth (+ depth signum)))
1033     (when (< (* depth signum) 0)
1034       ;; Moving end -> end or beginning -> beginning.
1035       (setq depth 0))
1036     (dotimes (_ (abs n))
1037       (setq done nil)
1038       (setq down (save-excursion
1039                    (back-to-indentation)
1040                    ;; There is a block start or block end keyword on this
1041                    ;; line, don't need to look for another block.
1042                    (and (re-search-forward
1043                          (if backward ruby-block-end-re
1044                            (concat "\\_<\\(" ruby-block-beg-re "\\)\\_>"))
1045                          (line-end-position) t)
1046                         (not (nth 8 (syntax-ppss))))))
1047       (while (and (not done) (not (if backward (bobp) (eobp))))
1048         (forward-line signum)
1049         (cond
1050          ;; Skip empty and commented out lines.
1051          ((looking-at "^\\s *$"))
1052          ((looking-at "^\\s *#"))
1053          ;; Skip block comments;
1054          ((and (not backward) (looking-at "^=begin\\>"))
1055           (re-search-forward "^=end\\>"))
1056          ((and backward (looking-at "^=end\\>"))
1057           (re-search-backward "^=begin\\>"))
1058          ;; Jump over a multiline literal.
1059          ((ruby-in-ppss-context-p 'string)
1060           (goto-char (nth 8 (syntax-ppss)))
1061           (unless backward
1062             (forward-sexp)
1063             (when (bolp) (forward-char -1)))) ; After a heredoc.
1064          (t
1065           (let ((state (ruby-parse-region (point) (line-end-position))))
1066             (unless (car state) ; Line ends with unfinished string.
1067               (setq depth (+ (nth 2 state) depth))))
1068           (cond
1069            ;; Increased depth, we found a block.
1070            ((> (* signum depth) 0)
1071             (setq down t))
1072            ;; We're at the same depth as when we started, and we've
1073            ;; encountered a block before.  Stop.
1074            ((and down (zerop depth))
1075             (setq done t))
1076            ;; Lower depth, means outer block, can stop now.
1077            ((< (* signum depth) 0)
1078             (setq done t)))))))
1079     (back-to-indentation)))
1080
1081 (defun ruby-beginning-of-block (&optional arg)
1082   "Move backward to the beginning of the current block.
1083 With ARG, move up multiple blocks."
1084   (interactive "p")
1085   (ruby-move-to-block (- (or arg 1))))
1086
1087 (defun ruby-end-of-block (&optional arg)
1088   "Move forward to the end of the current block.
1089 With ARG, move out of multiple blocks."
1090   (interactive "p")
1091   (ruby-move-to-block (or arg 1)))
1092
1093 (defun ruby-forward-sexp (&optional arg)
1094   "Move forward across one balanced expression (sexp).
1095 With ARG, do it many times.  Negative ARG means move backward."
1096   ;; TODO: Document body
1097   (interactive "p")
1098   (if (and (numberp arg) (< arg 0))
1099       (ruby-backward-sexp (- arg))
1100     (let ((i (or arg 1)))
1101       (condition-case nil
1102           (while (> i 0)
1103             (skip-syntax-forward " ")
1104             (if (looking-at ",\\s *") (goto-char (match-end 0)))
1105             (cond ((looking-at "\\?\\(\\\\[CM]-\\)*\\\\?\\S ")
1106                    (goto-char (match-end 0)))
1107                   ((progn
1108                      (skip-chars-forward ",.:;|&^~=!?\\+\\-\\*")
1109                      (looking-at "\\s("))
1110                    (goto-char (scan-sexps (point) 1)))
1111                   ((and (looking-at (concat "\\<\\(" ruby-block-beg-re "\\)\\>"))
1112                         (not (eq (char-before (point)) ?.))
1113                         (not (eq (char-before (point)) ?:)))
1114                    (ruby-end-of-block)
1115                    (forward-word 1))
1116                   ((looking-at "\\(\\$\\|@@?\\)?\\sw")
1117                    (while (progn
1118                             (while (progn (forward-word 1) (looking-at "_")))
1119                             (cond ((looking-at "::") (forward-char 2) t)
1120                                   ((> (skip-chars-forward ".") 0))
1121                                   ((looking-at "\\?\\|!\\(=[~=>]\\|[^~=]\\)")
1122                                    (forward-char 1) nil)))))
1123                   ((let (state expr)
1124                      (while
1125                          (progn
1126                            (setq expr (or expr (ruby-expr-beg)
1127                                           (looking-at "%\\sw?\\Sw\\|[\"'`/]")))
1128                            (nth 1 (setq state (apply 'ruby-parse-partial nil state))))
1129                        (setq expr t)
1130                        (skip-chars-forward "<"))
1131                      (not expr))))
1132             (setq i (1- i)))
1133         ((error) (forward-word 1)))
1134       i)))
1135
1136 (defun ruby-backward-sexp (&optional arg)
1137   "Move backward across one balanced expression (sexp).
1138 With ARG, do it many times.  Negative ARG means move forward."
1139   ;; TODO: Document body
1140   (interactive "p")
1141   (if (and (numberp arg) (< arg 0))
1142       (ruby-forward-sexp (- arg))
1143     (let ((i (or arg 1)))
1144       (condition-case nil
1145           (while (> i 0)
1146             (skip-chars-backward " \t\n,.:;|&^~=!?\\+\\-\\*")
1147             (forward-char -1)
1148             (cond ((looking-at "\\s)")
1149                    (goto-char (scan-sexps (1+ (point)) -1))
1150                    (case (char-before)
1151                      (?% (forward-char -1))
1152                      ((?q ?Q ?w ?W ?r ?x)
1153                       (if (eq (char-before (1- (point))) ?%) (forward-char -2))))
1154                    nil)
1155                   ((looking-at "\\s\"\\|\\\\\\S_")
1156                    (let ((c (char-to-string (char-before (match-end 0)))))
1157                      (while (and (search-backward c)
1158                                  (eq (logand (skip-chars-backward "\\") 1)
1159                                      1))))
1160                    nil)
1161                   ((looking-at "\\s.\\|\\s\\")
1162                    (if (ruby-special-char-p) (forward-char -1)))
1163                   ((looking-at "\\s(") nil)
1164                   (t
1165                    (forward-char 1)
1166                    (while (progn (forward-word -1)
1167                                  (case (char-before)
1168                                    (?_ t)
1169                                    (?. (forward-char -1) t)
1170                                    ((?$ ?@)
1171                                     (forward-char -1)
1172                                     (and (eq (char-before) (char-after)) (forward-char -1)))
1173                                    (?:
1174                                     (forward-char -1)
1175                                     (eq (char-before) :)))))
1176                    (if (looking-at ruby-block-end-re)
1177                        (ruby-beginning-of-block))
1178                    nil))
1179             (setq i (1- i)))
1180         ((error)))
1181       i)))
1182
1183 (defun ruby-indent-exp (&optional ignored)
1184   "Indent each line in the balanced expression following the point."
1185   (interactive "*P")
1186   (let ((here (point-marker)) start top column (nest t))
1187     (set-marker-insertion-type here t)
1188     (unwind-protect
1189         (progn
1190           (beginning-of-line)
1191           (setq start (point) top (current-indentation))
1192           (while (and (not (eobp))
1193                       (progn
1194                         (setq column (ruby-calculate-indent start))
1195                         (cond ((> column top)
1196                                (setq nest t))
1197                               ((and (= column top) nest)
1198                                (setq nest nil) t))))
1199             (ruby-indent-to column)
1200             (beginning-of-line 2)))
1201       (goto-char here)
1202       (set-marker here nil))))
1203
1204 (defun ruby-add-log-current-method ()
1205   "Return the current method name as a string.
1206 This string includes all namespaces.
1207
1208 For example:
1209
1210   #exit
1211   String#gsub
1212   Net::HTTP#active?
1213   File.open
1214
1215 See `add-log-current-defun-function'."
1216   (condition-case nil
1217       (save-excursion
1218         (let* ((indent 0) mname mlist
1219                (start (point))
1220                (make-definition-re
1221                 (lambda (re)
1222                   (concat "^[ \t]*" re "[ \t]+"
1223                           "\\("
1224                           ;; \\. and :: for class methods
1225                           "\\([A-Za-z_]" ruby-symbol-re "*\\|\\.\\|::" "\\)"
1226                           "+\\)")))
1227                (definition-re (funcall make-definition-re ruby-defun-beg-re))
1228                (module-re (funcall make-definition-re "\\(class\\|module\\)")))
1229           ;; Get the current method definition (or class/module).
1230           (when (re-search-backward definition-re nil t)
1231             (goto-char (match-beginning 1))
1232             (if (not (string-equal "def" (match-string 1)))
1233                 (setq mlist (list (match-string 2)))
1234               ;; We're inside the method. For classes and modules,
1235               ;; this check is skipped for performance.
1236               (when (ruby-block-contains-point start)
1237                 (setq mname (match-string 2))))
1238             (setq indent (current-column))
1239             (beginning-of-line))
1240           ;; Walk up the class/module nesting.
1241           (while (and (> indent 0)
1242                       (re-search-backward module-re nil t))
1243             (goto-char (match-beginning 1))
1244             (when (< (current-column) indent)
1245               (setq mlist (cons (match-string 2) mlist))
1246               (setq indent (current-column))
1247               (beginning-of-line)))
1248           ;; Process the method name.
1249           (when mname
1250             (let ((mn (split-string mname "\\.\\|::")))
1251               (if (cdr mn)
1252                   (progn
1253                     (unless (string-equal "self" (car mn)) ; def self.foo
1254                       ;; def C.foo
1255                       (let ((ml (nreverse mlist)))
1256                         ;; If the method name references one of the
1257                         ;; containing modules, drop the more nested ones.
1258                         (while ml
1259                           (if (string-equal (car ml) (car mn))
1260                               (setq mlist (nreverse (cdr ml)) ml nil))
1261                           (or (setq ml (cdr ml)) (nreverse mlist))))
1262                       (if mlist
1263                           (setcdr (last mlist) (butlast mn))
1264                         (setq mlist (butlast mn))))
1265                     (setq mname (concat "." (car (last mn)))))
1266                 ;; See if the method is in singleton class context.
1267                 (let ((in-singleton-class
1268                        (when (re-search-forward ruby-singleton-class-re start t)
1269                          (goto-char (match-beginning 0))
1270                          ;; FIXME: Optimize it out, too?
1271                          ;; This can be slow in a large file, but
1272                          ;; unlike class/module declaration
1273                          ;; indentations, method definitions can be
1274                          ;; intermixed with these, and may or may not
1275                          ;; be additionally indented after visibility
1276                          ;; keywords.
1277                          (ruby-block-contains-point start))))
1278                   (setq mname (concat
1279                                (if in-singleton-class "." "#")
1280                                mname))))))
1281           ;; Generate the string.
1282           (if (consp mlist)
1283               (setq mlist (mapconcat (function identity) mlist "::")))
1284           (if mname
1285               (if mlist (concat mlist mname) mname)
1286             mlist)))))
1287
1288 (defun ruby-block-contains-point (pt)
1289   (save-excursion
1290     (save-match-data
1291       (ruby-forward-sexp)
1292       (> (point) pt))))
1293
1294 (defun ruby-brace-to-do-end (orig end)
1295   (let (beg-marker end-marker)
1296     (goto-char end)
1297     (when (eq (char-before) ?\})
1298       (delete-char -1)
1299       (when (save-excursion
1300               (skip-chars-backward " \t")
1301               (not (bolp)))
1302         (insert "\n"))
1303       (insert "end")
1304       (setq end-marker (point-marker))
1305       (when (and (not (eobp)) (eq (char-syntax (char-after)) ?w))
1306         (insert " "))
1307       (goto-char orig)
1308       (delete-char 1)
1309       (when (eq (char-syntax (char-before)) ?w)
1310         (insert " "))
1311       (insert "do")
1312       (setq beg-marker (point-marker))
1313       (when (looking-at "\\(\\s \\)*|")
1314         (unless (match-beginning 1)
1315           (insert " "))
1316         (goto-char (1+ (match-end 0)))
1317         (search-forward "|"))
1318       (unless (looking-at "\\s *$")
1319         (insert "\n"))
1320       (indent-region beg-marker end-marker)
1321       (goto-char beg-marker)
1322       t)))
1323
1324 (defun ruby-do-end-to-brace (orig end)
1325   (let (beg-marker end-marker beg-pos end-pos)
1326     (goto-char (- end 3))
1327     (when (looking-at ruby-block-end-re)
1328       (delete-char 3)
1329       (setq end-marker (point-marker))
1330       (insert "}")
1331       (goto-char orig)
1332       (delete-char 2)
1333       (insert "{")
1334       (setq beg-marker (point-marker))
1335       (when (looking-at "\\s +|")
1336         (delete-char (- (match-end 0) (match-beginning 0) 1))
1337         (forward-char)
1338         (re-search-forward "|" (line-end-position) t))
1339       (save-excursion
1340         (skip-chars-forward " \t\n\r")
1341         (setq beg-pos (point))
1342         (goto-char end-marker)
1343         (skip-chars-backward " \t\n\r")
1344         (setq end-pos (point)))
1345       (when (or
1346              (< end-pos beg-pos)
1347              (and (= (line-number-at-pos beg-pos) (line-number-at-pos end-pos))
1348                   (< (+ (current-column) (- end-pos beg-pos) 2) fill-column)))
1349         (just-one-space -1)
1350         (goto-char end-marker)
1351         (just-one-space -1))
1352       (goto-char beg-marker)
1353       t)))
1354
1355 (defun ruby-toggle-block ()
1356   "Toggle block type from do-end to braces or back.
1357 The block must begin on the current line or above it and end after the point.
1358 If the result is do-end block, it will always be multiline."
1359   (interactive)
1360   (let ((start (point)) beg end)
1361     (end-of-line)
1362     (unless
1363         (if (and (re-search-backward "\\({\\)\\|\\_<do\\(\\s \\|$\\||\\)")
1364                  (progn
1365                    (setq beg (point))
1366                    (save-match-data (ruby-forward-sexp))
1367                    (setq end (point))
1368                    (> end start)))
1369             (if (match-beginning 1)
1370                 (ruby-brace-to-do-end beg end)
1371               (ruby-do-end-to-brace beg end)))
1372       (goto-char start))))
1373
1374 (declare-function ruby-syntax-propertize-heredoc "ruby-mode" (limit))
1375 (declare-function ruby-syntax-enclosing-percent-literal "ruby-mode" (limit))
1376 (declare-function ruby-syntax-propertize-percent-literal "ruby-mode" (limit))
1377 ;; Unusual code layout confuses the byte-compiler.
1378 (declare-function ruby-syntax-propertize-expansion "ruby-mode" ())
1379 (declare-function ruby-syntax-expansion-allowed-p "ruby-mode" (parse-state))
1380 (declare-function ruby-syntax-propertize-function "ruby-mode" (start end))
1381
1382 (if (eval-when-compile (fboundp #'syntax-propertize-rules))
1383     ;; New code that works independently from font-lock.
1384     (progn
1385       (eval-and-compile
1386         (defconst ruby-percent-literal-beg-re
1387           "\\(%\\)[qQrswWxIi]?\\([[:punct:]]\\)"
1388           "Regexp to match the beginning of percent literal.")
1389
1390         (defconst ruby-syntax-methods-before-regexp
1391           '("gsub" "gsub!" "sub" "sub!" "scan" "split" "split!" "index" "match"
1392             "assert_match" "Given" "Then" "When")
1393           "Methods that can take regexp as the first argument.
1394 It will be properly highlighted even when the call omits parens.")
1395
1396         (defvar ruby-syntax-before-regexp-re
1397           (concat
1398            ;; Special tokens that can't be followed by a division operator.
1399            "\\(^\\|[[=(,~;<>]"
1400            ;; Distinguish ternary operator tokens.
1401            ;; FIXME: They don't really have to be separated with spaces.
1402            "\\|[?:] "
1403            ;; Control flow keywords and operators following bol or whitespace.
1404            "\\|\\(?:^\\|\\s \\)"
1405            (regexp-opt '("if" "elsif" "unless" "while" "until" "when" "and"
1406                          "or" "not" "&&" "||"))
1407            ;; Method name from the list.
1408            "\\|\\_<"
1409            (regexp-opt ruby-syntax-methods-before-regexp)
1410            "\\)\\s *")
1411           "Regexp to match text that can be followed by a regular expression."))
1412
1413       (defun ruby-syntax-propertize-function (start end)
1414         "Syntactic keywords for Ruby mode.  See `syntax-propertize-function'."
1415         (let (case-fold-search)
1416           (goto-char start)
1417           (remove-text-properties start end '(ruby-expansion-match-data))
1418           (ruby-syntax-propertize-heredoc end)
1419           (ruby-syntax-enclosing-percent-literal end)
1420           (funcall
1421            (syntax-propertize-rules
1422             ;; $' $" $` .... are variables.
1423             ;; ?' ?" ?` are character literals (one-char strings in 1.9+).
1424             ("\\([?$]\\)[#\"'`]"
1425              (1 (unless (save-excursion
1426                           ;; Not within a string.
1427                           (nth 3 (syntax-ppss (match-beginning 0))))
1428                   (string-to-syntax "\\"))))
1429             ;; Regular expressions.  Start with matching unescaped slash.
1430             ("\\(?:\\=\\|[^\\]\\)\\(?:\\\\\\\\\\)*\\(/\\)"
1431              (1 (let ((state (save-excursion (syntax-ppss (match-beginning 1)))))
1432                   (when (or
1433                          ;; Beginning of a regexp.
1434                          (and (null (nth 8 state))
1435                               (save-excursion
1436                                 (forward-char -1)
1437                                 (looking-back ruby-syntax-before-regexp-re
1438                                               (point-at-bol))))
1439                          ;; End of regexp.  We don't match the whole
1440                          ;; regexp at once because it can have
1441                          ;; string interpolation inside, or span
1442                          ;; several lines.
1443                          (eq ?/ (nth 3 state)))
1444                     (string-to-syntax "\"/")))))
1445             ;; Expression expansions in strings.  We're handling them
1446             ;; here, so that the regexp rule never matches inside them.
1447             (ruby-expression-expansion-re
1448              (0 (ignore (ruby-syntax-propertize-expansion))))
1449             ("^=en\\(d\\)\\_>" (1 "!"))
1450             ("^\\(=\\)begin\\_>" (1 "!"))
1451             ;; Handle here documents.
1452             ((concat ruby-here-doc-beg-re ".*\\(\n\\)")
1453              (7 (unless (or (nth 8 (save-excursion
1454                                      (syntax-ppss (match-beginning 0))))
1455                             (ruby-singleton-class-p (match-beginning 0)))
1456                   (put-text-property (match-beginning 7) (match-end 7)
1457                                      'syntax-table (string-to-syntax "\""))
1458                   (ruby-syntax-propertize-heredoc end))))
1459             ;; Handle percent literals: %w(), %q{}, etc.
1460             ((concat "\\(?:^\\|[[ \t\n<+(,=]\\)" ruby-percent-literal-beg-re)
1461              (1 (prog1 "|" (ruby-syntax-propertize-percent-literal end)))))
1462            (point) end)))
1463
1464       (defun ruby-syntax-propertize-heredoc (limit)
1465         (let ((ppss (syntax-ppss))
1466               (res '()))
1467           (when (eq ?\n (nth 3 ppss))
1468             (save-excursion
1469               (goto-char (nth 8 ppss))
1470               (beginning-of-line)
1471               (while (re-search-forward ruby-here-doc-beg-re
1472                                         (line-end-position) t)
1473                 (unless (ruby-singleton-class-p (match-beginning 0))
1474                   (push (concat (ruby-here-doc-end-match) "\n") res))))
1475             (save-excursion
1476               ;; With multiple openers on the same line, we don't know in which
1477               ;; part `start' is, so we have to go back to the beginning.
1478               (when (cdr res)
1479                 (goto-char (nth 8 ppss))
1480                 (setq res (nreverse res)))
1481               (while (and res (re-search-forward (pop res) limit 'move))
1482                 (if (null res)
1483                     (put-text-property (1- (point)) (point)
1484                                        'syntax-table (string-to-syntax "\""))))
1485               ;; End up at bol following the heredoc openers.
1486               ;; Propertize expression expansions from this point forward.
1487               ))))
1488
1489       (defun ruby-syntax-enclosing-percent-literal (limit)
1490         (let ((state (syntax-ppss))
1491               (start (point)))
1492           ;; When already inside percent literal, re-propertize it.
1493           (when (eq t (nth 3 state))
1494             (goto-char (nth 8 state))
1495             (when (looking-at ruby-percent-literal-beg-re)
1496               (ruby-syntax-propertize-percent-literal limit))
1497             (when (< (point) start) (goto-char start)))))
1498
1499       (defun ruby-syntax-propertize-percent-literal (limit)
1500         (goto-char (match-beginning 2))
1501         ;; Not inside a simple string or comment.
1502         (when (eq t (nth 3 (syntax-ppss)))
1503           (let* ((op (char-after))
1504                  (ops (char-to-string op))
1505                  (cl (or (cdr (aref (syntax-table) op))
1506                          (cdr (assoc op '((?< . ?>))))))
1507                  parse-sexp-lookup-properties)
1508             (save-excursion
1509               (condition-case nil
1510                   (progn
1511                     (if cl              ; Paired delimiters.
1512                         ;; Delimiter pairs of the same kind can be nested
1513                         ;; inside the literal, as long as they are balanced.
1514                         ;; Create syntax table that ignores other characters.
1515                         (with-syntax-table (make-char-table 'syntax-table nil)
1516                           (modify-syntax-entry op (concat "(" (char-to-string cl)))
1517                           (modify-syntax-entry cl (concat ")" ops))
1518                           (modify-syntax-entry ?\\ "\\")
1519                           (save-restriction
1520                             (narrow-to-region (point) limit)
1521                             (forward-list))) ; skip to the paired character
1522                       ;; Single character delimiter.
1523                       (re-search-forward (concat "[^\\]\\(?:\\\\\\\\\\)*"
1524                                                  (regexp-quote ops)) limit nil))
1525                     ;; Found the closing delimiter.
1526                     (put-text-property (1- (point)) (point) 'syntax-table
1527                                        (string-to-syntax "|")))
1528                 ;; Unclosed literal, do nothing.
1529                 ((scan-error search-failed)))))))
1530
1531       (defun ruby-syntax-propertize-expansion ()
1532         ;; Save the match data to a text property, for font-locking later.
1533         ;; Set the syntax of all double quotes and backticks to punctuation.
1534         (let* ((beg (match-beginning 2))
1535                (end (match-end 2))
1536                (state (and beg (save-excursion (syntax-ppss beg)))))
1537           (when (ruby-syntax-expansion-allowed-p state)
1538             (put-text-property beg (1+ beg) 'ruby-expansion-match-data
1539                                (match-data))
1540             (goto-char beg)
1541             (while (re-search-forward "[\"`]" end 'move)
1542               (put-text-property (match-beginning 0) (match-end 0)
1543                                  'syntax-table (string-to-syntax "."))))))
1544
1545       (defun ruby-syntax-expansion-allowed-p (parse-state)
1546         "Return non-nil if expression expansion is allowed."
1547         (let ((term (nth 3 parse-state)))
1548           (cond
1549            ((memq term '(?\" ?` ?\n ?/)))
1550            ((eq term t)
1551             (save-match-data
1552               (save-excursion
1553                 (goto-char (nth 8 parse-state))
1554                 (looking-at "%\\(?:[QWrxI]\\|\\W\\)")))))))
1555
1556       (defun ruby-syntax-propertize-expansions (start end)
1557         (save-excursion
1558           (goto-char start)
1559           (while (re-search-forward ruby-expression-expansion-re end 'move)
1560             (ruby-syntax-propertize-expansion))))
1561       )
1562
1563   ;; For Emacsen where syntax-propertize-rules is not (yet) available,
1564   ;; fallback on the old font-lock-syntactic-keywords stuff.
1565
1566   (defconst ruby-here-doc-end-re
1567     "^\\([ \t]+\\)?\\(.*\\)\\(\n\\)"
1568     "Regexp to match the end of heredocs.
1569
1570 This will actually match any line with one or more characters.
1571 It's useful in that it divides up the match string so that
1572 `ruby-here-doc-beg-match' can search for the beginning of the heredoc.")
1573
1574   (defun ruby-here-doc-beg-match ()
1575     "Return a regexp to find the beginning of a heredoc.
1576
1577 This should only be called after matching against `ruby-here-doc-end-re'."
1578     (let ((contents (concat
1579                      (regexp-quote (concat (match-string 2) (match-string 3)))
1580                      (if (string= (match-string 3) "_") "\\B" "\\b"))))
1581       (concat "<<"
1582               (let ((match (match-string 1)))
1583                 (if (and match (> (length match) 0))
1584                     (concat "\\(?:-\\([\"']?\\)\\|\\([\"']\\)"
1585                             (match-string 1) "\\)"
1586                             contents "\\(\\1\\|\\2\\)")
1587                   (concat "-?\\([\"']\\|\\)" contents "\\1"))))))
1588
1589   (defconst ruby-font-lock-syntactic-keywords
1590     `(
1591     ;; the last $', $", $` in the respective string is not variable
1592     ;; the last ?', ?", ?` in the respective string is not ascii code
1593     ("\\(^\\|[\[ \t\n<+\(,=]\\)\\(['\"`]\\)\\(\\\\.\\|\\2\\|[^'\"`\n\\\\]\\)*?\\\\?[?$]\\(\\2\\)"
1594      (2 (7 . nil))
1595      (4 (7 . nil)))
1596     ;; $' $" $` .... are variables
1597     ;; ?' ?" ?` are ascii codes
1598     ("\\(^\\|[^\\\\]\\)\\(\\\\\\\\\\)*[?$]\\([#\"'`]\\)" 3 (1 . nil))
1599     ;; regexps
1600     ("\\(^\\|[[=(,~?:;<>]\\|\\(^\\|\\s \\)\\(if\\|elsif\\|unless\\|while\\|until\\|when\\|and\\|or\\|&&\\|||\\)\\|g?sub!?\\|scan\\|split!?\\)\\s *\\(/\\)[^/\n\\\\]*\\(\\\\.[^/\n\\\\]*\\)*\\(/\\)"
1601      (4 (7 . ?/))
1602      (6 (7 . ?/)))
1603     ("^=en\\(d\\)\\_>" 1 "!")
1604     ;; Percent literal.
1605     ("\\(^\\|[[ \t\n<+(,=]\\)\\(%[xrqQwW]?\\([^<[{(a-zA-Z0-9 \n]\\)[^\n\\\\]*\\(\\\\.[^\n\\\\]*\\)*\\(\\3\\)\\)"
1606      (3 "\"")
1607      (5 "\""))
1608     ("^\\(=\\)begin\\_>" 1 (ruby-comment-beg-syntax))
1609     ;; Currently, the following case is highlighted incorrectly:
1610     ;;
1611     ;;   <<FOO
1612     ;;   FOO
1613     ;;   <<BAR
1614     ;;   <<BAZ
1615     ;;   BAZ
1616     ;;   BAR
1617     ;;
1618     ;; This is because all here-doc beginnings are highlighted before any endings,
1619     ;; so although <<BAR is properly marked as a beginning, when we get to <<BAZ
1620     ;; it thinks <<BAR is part of a string so it's marked as well.
1621     ;;
1622     ;; This may be fixable by modifying ruby-in-here-doc-p to use
1623     ;; ruby-in-non-here-doc-string-p rather than syntax-ppss-context,
1624     ;; but I don't want to try that until we've got unit tests set up
1625     ;; to make sure I don't break anything else.
1626     (,(concat ruby-here-doc-beg-re ".*\\(\n\\)")
1627      ,(+ 1 (regexp-opt-depth ruby-here-doc-beg-re))
1628      (ruby-here-doc-beg-syntax))
1629     (,ruby-here-doc-end-re 3 (ruby-here-doc-end-syntax)))
1630   "Syntactic keywords for Ruby mode.  See `font-lock-syntactic-keywords'.")
1631
1632   (defun ruby-comment-beg-syntax ()
1633   "Return the syntax cell for a the first character of a =begin.
1634 See the definition of `ruby-font-lock-syntactic-keywords'.
1635
1636 This returns a comment-delimiter cell as long as the =begin
1637 isn't in a string or another comment."
1638     (when (not (nth 3 (syntax-ppss)))
1639       (string-to-syntax "!")))
1640
1641   (defun ruby-in-here-doc-p ()
1642     "Return whether or not the point is in a heredoc."
1643     (save-excursion
1644       (let ((old-point (point)) (case-fold-search nil))
1645         (beginning-of-line)
1646         (catch 'found-beg
1647           (while (and (re-search-backward ruby-here-doc-beg-re nil t)
1648                       (not (ruby-singleton-class-p)))
1649             (if (not (or (ruby-in-ppss-context-p 'anything)
1650                          (ruby-here-doc-find-end old-point)))
1651                 (throw 'found-beg t)))))))
1652
1653   (defun ruby-here-doc-find-end (&optional limit)
1654     "Expects the point to be on a line with one or more heredoc openers.
1655 Returns the buffer position at which all heredocs on the line
1656 are terminated, or nil if they aren't terminated before the
1657 buffer position `limit' or the end of the buffer."
1658     (save-excursion
1659       (beginning-of-line)
1660       (catch 'done
1661         (let ((eol (point-at-eol))
1662               (case-fold-search nil)
1663               ;; Fake match data such that (match-end 0) is at eol
1664               (end-match-data (progn (looking-at ".*$") (match-data)))
1665               beg-match-data end-re)
1666           (while (re-search-forward ruby-here-doc-beg-re eol t)
1667             (setq beg-match-data (match-data))
1668             (setq end-re (ruby-here-doc-end-match))
1669
1670             (set-match-data end-match-data)
1671             (goto-char (match-end 0))
1672             (unless (re-search-forward end-re limit t) (throw 'done nil))
1673             (setq end-match-data (match-data))
1674
1675             (set-match-data beg-match-data)
1676             (goto-char (match-end 0)))
1677           (set-match-data end-match-data)
1678           (goto-char (match-end 0))
1679           (point)))))
1680
1681   (defun ruby-here-doc-beg-syntax ()
1682     "Return the syntax cell for a line that may begin a heredoc.
1683 See the definition of `ruby-font-lock-syntactic-keywords'.
1684
1685 This sets the syntax cell for the newline ending the line
1686 containing the heredoc beginning so that cases where multiple
1687 heredocs are started on one line are handled correctly."
1688     (save-excursion
1689       (goto-char (match-beginning 0))
1690       (unless (or (ruby-in-ppss-context-p 'non-heredoc)
1691                   (ruby-in-here-doc-p))
1692         (string-to-syntax "\""))))
1693
1694   (defun ruby-here-doc-end-syntax ()
1695     "Return the syntax cell for a line that may end a heredoc.
1696 See the definition of `ruby-font-lock-syntactic-keywords'."
1697     (let ((pss (syntax-ppss)) (case-fold-search nil))
1698       ;; If we aren't in a string, we definitely aren't ending a heredoc,
1699       ;; so we can just give up.
1700       ;; This means we aren't doing a full-document search
1701       ;; every time we enter a character.
1702       (when (ruby-in-ppss-context-p 'heredoc pss)
1703         (save-excursion
1704           (goto-char (nth 8 pss))    ; Go to the beginning of heredoc.
1705           (let ((eol (point)))
1706             (beginning-of-line)
1707             (if (and (re-search-forward (ruby-here-doc-beg-match) eol t) ; If there is a heredoc that matches this line...
1708                      (not (ruby-in-ppss-context-p 'anything)) ; And that's not inside a heredoc/string/comment...
1709                      (progn (goto-char (match-end 0)) ; And it's the last heredoc on its line...
1710                             (not (re-search-forward ruby-here-doc-beg-re eol t))))
1711                 (string-to-syntax "\"")))))))
1712
1713   (unless (functionp 'syntax-ppss)
1714     (defun syntax-ppss (&optional pos)
1715       (parse-partial-sexp (point-min) (or pos (point)))))
1716   )
1717
1718 (defun ruby-in-ppss-context-p (context &optional ppss)
1719   (let ((ppss (or ppss (syntax-ppss (point)))))
1720     (if (cond
1721          ((eq context 'anything)
1722           (or (nth 3 ppss)
1723               (nth 4 ppss)))
1724          ((eq context 'string)
1725           (nth 3 ppss))
1726          ((eq context 'heredoc)
1727           (eq ?\n (nth 3 ppss)))
1728          ((eq context 'non-heredoc)
1729           (and (ruby-in-ppss-context-p 'anything)
1730                (not (ruby-in-ppss-context-p 'heredoc))))
1731          ((eq context 'comment)
1732           (nth 4 ppss))
1733          (t
1734           (error (concat
1735                   "Internal error on `ruby-in-ppss-context-p': "
1736                   "context name `" (symbol-name context) "' is unknown"))))
1737         t)))
1738
1739 (if (featurep 'xemacs)
1740     (put 'ruby-mode 'font-lock-defaults
1741          '((ruby-font-lock-keywords)
1742            nil nil nil
1743            beginning-of-line
1744            (font-lock-syntactic-keywords
1745             . ruby-font-lock-syntactic-keywords))))
1746
1747 (defvar ruby-font-lock-syntax-table
1748   (let ((tbl (copy-syntax-table ruby-mode-syntax-table)))
1749     (modify-syntax-entry ?_ "w" tbl)
1750     tbl)
1751   "The syntax table to use for fontifying Ruby mode buffers.
1752 See `font-lock-syntax-table'.")
1753
1754 (defconst ruby-font-lock-keyword-beg-re "\\(?:^\\|[^.@$]\\|\\.\\.\\)")
1755
1756 (defconst ruby-font-lock-keywords
1757   (list
1758    ;; functions
1759    '("^\\s *def\\s +\\(?:[^( \t\n.]*\\.\\)?\\([^( \t\n]+\\)"
1760      1 font-lock-function-name-face)
1761    ;; keywords
1762    (list (concat
1763           ruby-font-lock-keyword-beg-re
1764           (regexp-opt
1765            '("alias"
1766              "and"
1767              "begin"
1768              "break"
1769              "case"
1770              "class"
1771              "def"
1772              "defined?"
1773              "do"
1774              "elsif"
1775              "else"
1776              "fail"
1777              "ensure"
1778              "for"
1779              "end"
1780              "if"
1781              "in"
1782              "module"
1783              "next"
1784              "not"
1785              "or"
1786              "redo"
1787              "rescue"
1788              "retry"
1789              "return"
1790              "then"
1791              "super"
1792              "unless"
1793              "undef"
1794              "until"
1795              "when"
1796              "while"
1797              "yield")
1798            'symbols))
1799          1 'font-lock-keyword-face)
1800    ;; some core methods
1801    (list (concat
1802           ruby-font-lock-keyword-beg-re
1803           (regexp-opt
1804            '(;; built-in methods on Kernel
1805              "__callee__"
1806              "__dir__"
1807              "__method__"
1808              "abort"
1809              "at_exit"
1810              "autoload"
1811              "autoload?"
1812              "binding"
1813              "block_given?"
1814              "caller"
1815              "catch"
1816              "eval"
1817              "exec"
1818              "exit"
1819              "exit!"
1820              "fail"
1821              "fork"
1822              "format"
1823              "lambda"
1824              "load"
1825              "loop"
1826              "open"
1827              "p"
1828              "print"
1829              "printf"
1830              "proc"
1831              "putc"
1832              "puts"
1833              "raise"
1834              "rand"
1835              "readline"
1836              "readlines"
1837              "require"
1838              "require_relative"
1839              "sleep"
1840              "spawn"
1841              "sprintf"
1842              "srand"
1843              "syscall"
1844              "system"
1845              "throw"
1846              "trap"
1847              "warn"
1848              ;; keyword-like private methods on Module
1849              "alias_method"
1850              "attr"
1851              "attr_accessor"
1852              "attr_reader"
1853              "attr_writer"
1854              "define_method"
1855              "extend"
1856              "include"
1857              "module_function"
1858              "prepend"
1859              "private"
1860              "protected"
1861              "public"
1862              "refine"
1863              "using")
1864            'symbols))
1865          1 'font-lock-builtin-face)
1866    ;; here-doc beginnings
1867    `(,ruby-here-doc-beg-re 0 (unless (ruby-singleton-class-p (match-beginning 0))
1868                                'font-lock-string-face))
1869    ;; Perl-ish keywords
1870    "\\_<\\(?:BEGIN\\|END\\)\\_>\\|^__END__$"
1871    ;; variables
1872    `(,(concat ruby-font-lock-keyword-beg-re
1873               "\\_<\\(nil\\|self\\|true\\|false\\)\\>")
1874      1 font-lock-variable-name-face)
1875    ;; keywords that evaluate to certain values
1876    '("\\_<__\\(?:LINE\\|ENCODING\\|FILE\\)__\\_>" 0 font-lock-variable-name-face)
1877    ;; symbols
1878    '("\\(^\\|[^:]\\)\\(:\\([-+~]@?\\|[/%&|^`]\\|\\*\\*?\\|<\\(<\\|=>?\\)?\\|>[>=]?\\|===?\\|=~\\|![~=]?\\|\\[\\]=?\\|@?\\(\\w\\|_\\)+\\([!?=]\\|\\b_*\\)\\|#{[^}\n\\\\]*\\(\\\\.[^}\n\\\\]*\\)*}\\)\\)"
1879      2 font-lock-constant-face)
1880    ;; variables
1881    '("\\(\\$\\([^a-zA-Z0-9 \n]\\|[0-9]\\)\\)\\W"
1882      1 font-lock-variable-name-face)
1883    '("\\(\\$\\|@\\|@@\\)\\(\\w\\|_\\)+"
1884      0 font-lock-variable-name-face)
1885    ;; constants
1886    '("\\(?:\\_<\\|::\\)\\([A-Z]+\\(\\w\\|_\\)*\\)"
1887      1 (unless (eq ?\( (char-after)) font-lock-type-face))
1888    '("\\(^\\s *\\|[\[\{\(,]\\s *\\|\\sw\\s +\\)\\(\\(\\sw\\|_\\)+\\):[^:]" 2 font-lock-constant-face)
1889    ;; conversion methods on Kernel
1890    (list (concat ruby-font-lock-keyword-beg-re
1891                  (regexp-opt '("Array" "Complex" "Float" "Hash"
1892                                "Integer" "Rational" "String") 'symbols))
1893          1 font-lock-builtin-face)
1894    ;; expression expansion
1895    '(ruby-match-expression-expansion
1896      2 font-lock-variable-name-face t)
1897    ;; negation char
1898    '("[^[:alnum:]_]\\(!\\)[^=]"
1899      1 font-lock-negation-char-face)
1900    ;; character literals
1901    ;; FIXME: Support longer escape sequences.
1902    '("\\_<\\?\\\\?\\S " 0 font-lock-string-face)
1903    )
1904   "Additional expressions to highlight in Ruby mode.")
1905
1906 (defun ruby-match-expression-expansion (limit)
1907   (let* ((prop 'ruby-expansion-match-data)
1908          (pos (next-single-char-property-change (point) prop nil limit))
1909          value)
1910     (when (and pos (> pos (point)))
1911       (goto-char pos)
1912       (or (and (setq value (get-text-property pos prop))
1913                (progn (set-match-data value) t))
1914           (ruby-match-expression-expansion limit)))))
1915
1916 ;;;###autoload
1917 (define-derived-mode ruby-mode prog-mode "Ruby"
1918   "Major mode for editing Ruby scripts.
1919 \\[ruby-indent-line] properly indents subexpressions of multi-line
1920 class, module, def, if, while, for, do, and case statements, taking
1921 nesting into account.
1922
1923 The variable `ruby-indent-level' controls the amount of indentation.
1924
1925 \\{ruby-mode-map}"
1926   (ruby-mode-variables)
1927
1928   (set (make-local-variable 'imenu-create-index-function)
1929        'ruby-imenu-create-index)
1930   (set (make-local-variable 'add-log-current-defun-function)
1931        'ruby-add-log-current-method)
1932   (set (make-local-variable 'beginning-of-defun-function)
1933        'ruby-beginning-of-defun)
1934   (set (make-local-variable 'end-of-defun-function)
1935        'ruby-end-of-defun)
1936
1937   (add-hook
1938    (cond ((boundp 'before-save-hook) 'before-save-hook)
1939          ((boundp 'write-contents-functions) 'write-contents-functions)
1940          ((boundp 'write-contents-hooks) 'write-contents-hooks))
1941    'ruby-mode-set-encoding nil 'local)
1942
1943   (set (make-local-variable 'electric-indent-chars)
1944        (append '(?\{ ?\}) electric-indent-chars))
1945
1946   (set (make-local-variable 'font-lock-defaults)
1947        '((ruby-font-lock-keywords) nil nil))
1948   (set (make-local-variable 'font-lock-keywords)
1949        ruby-font-lock-keywords)
1950   (set (make-local-variable 'font-lock-syntax-table)
1951        ruby-font-lock-syntax-table)
1952
1953   (if (eval-when-compile (fboundp 'syntax-propertize-rules))
1954       (set (make-local-variable 'syntax-propertize-function)
1955            #'ruby-syntax-propertize-function)
1956     (set (make-local-variable 'font-lock-syntactic-keywords)
1957          ruby-font-lock-syntactic-keywords)))
1958
1959 ;;; Invoke ruby-mode when appropriate
1960
1961 ;;;###autoload
1962 (add-to-list 'auto-mode-alist
1963              (cons (purecopy (concat "\\(?:\\."
1964                                      "rb\\|ru\\|rake\\|thor"
1965                                      "\\|jbuilder\\|gemspec"
1966                                      "\\|/"
1967                                      "\\(?:Gem\\|Rake\\|Cap\\|Thor"
1968                                      "Vagrant\\|Guard\\)file"
1969                                      "\\)\\'")) 'ruby-mode))
1970
1971 ;;;###autoload
1972 (dolist (name (list "ruby" "rbx" "jruby" "ruby1.9" "ruby1.8"))
1973   (add-to-list 'interpreter-mode-alist (cons (purecopy name) 'ruby-mode)))
1974
1975 (provide 'ruby-mode)
1976
1977 ;;; ruby-mode.el ends here