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