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