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