code.delx.au - gnu-emacs/blob - lisp/progmodes/ruby-mode.el

   1 ;;; ruby-mode.el --- Major mode for editing Ruby files
   2
   3 ;; Copyright (C) 1994-2013 Free Software Foundation, Inc.
   4
   5 ;; Authors: Yukihiro Matsumoto
   6 ;;      Nobuyoshi Nakada
   7 ;; URL: http://www.emacswiki.org/cgi-bin/wiki/RubyMode
   8 ;; Created: Fri Feb  4 14:49:13 JST 1994
   9 ;; Keywords: languages ruby
  10 ;; Version: 1.2
  11
  12 ;; This file is part of GNU Emacs.
  13
  14 ;; GNU Emacs is free software: you can redistribute it and/or modify
  15 ;; it under the terms of the GNU General Public License as published by
  16 ;; the Free Software Foundation, either version 3 of the License, or
  17 ;; (at your option) any later version.
  18
  19 ;; GNU Emacs is distributed in the hope that it will be useful,
  20 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 ;; GNU General Public License for more details.
  23
  24 ;; You should have received a copy of the GNU General Public License
  25 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  26
  27 ;;; Commentary:
  28
  29 ;; Provides font-locking, indentation support, and navigation for Ruby code.
  30 ;;
  31 ;; If you're installing manually, you should add this to your .emacs
  32 ;; file after putting it on your load path:
  33 ;;
  34 ;;    (autoload 'ruby-mode "ruby-mode" "Major mode for ruby files" t)
  35 ;;    (add-to-list 'auto-mode-alist '("\\.rb$" . ruby-mode))
  36 ;;    (add-to-list 'interpreter-mode-alist '("ruby" . ruby-mode))
  37 ;;
  38 ;; Still needs more docstrings; search below for TODO.
  39
  40 ;;; Code:
  41
  42 (eval-when-compile (require 'cl))
  43
  44 (defgroup ruby nil
  45   "Major mode for editing Ruby code."
  46   :prefix "ruby-"
  47   :group 'languages)
  48
  49 (defconst ruby-block-beg-keywords
  50   '("class" "module" "def" "if" "unless" "case" "while" "until" "for" "begin" "do")
  51   "Keywords at the beginning of blocks.")
  52
  53 (defconst ruby-block-beg-re
  54   (regexp-opt ruby-block-beg-keywords)
  55   "Regexp to match the beginning of blocks.")
  56
  57 (defconst ruby-non-block-do-re
  58   (regexp-opt '("while" "until" "for" "rescue") 'symbols)
  59   "Regexp to match keywords that nest without blocks.")
  60
  61 (defconst ruby-indent-beg-re
  62   (concat "^\\(\\s *" (regexp-opt '("class" "module" "def")) "\\|"
  63           (regexp-opt '("if" "unless" "case" "while" "until" "for" "begin"))
  64           "\\)\\_>")
  65   "Regexp to match where the indentation gets deeper.")
  66
  67 (defconst ruby-modifier-beg-keywords
  68   '("if" "unless" "while" "until")
  69   "Modifiers that are the same as the beginning of blocks.")
  70
  71 (defconst ruby-modifier-beg-re
  72   (regexp-opt ruby-modifier-beg-keywords)
  73   "Regexp to match modifiers same as the beginning of blocks.")
  74
  75 (defconst ruby-modifier-re
  76   (regexp-opt (cons "rescue" ruby-modifier-beg-keywords))
  77   "Regexp to match modifiers.")
  78
  79 (defconst ruby-block-mid-keywords
  80   '("then" "else" "elsif" "when" "rescue" "ensure")
  81   "Keywords where the indentation gets shallower in middle of block statements.")
  82
  83 (defconst ruby-block-mid-re
  84   (regexp-opt ruby-block-mid-keywords)
  85   "Regexp to match where the indentation gets shallower in middle of block statements.")
  86
  87 (defconst ruby-block-op-keywords
  88   '("and" "or" "not")
  89   "Regexp to match boolean keywords.")
  90
  91 (defconst ruby-block-hanging-re
  92   (regexp-opt (append ruby-modifier-beg-keywords ruby-block-op-keywords))
  93   "Regexp to match hanging block modifiers.")
  94
  95 (defconst ruby-block-end-re "\\_<end\\_>")
  96
  97 (defconst ruby-defun-beg-re
  98   '"\\(def\\|class\\|module\\)"
  99   "Regexp to match the beginning of a defun, in the general sense.")
 100
 101 (defconst ruby-singleton-class-re
 102   "class\\s *<<"
 103   "Regexp to match the beginning of a singleton class context.")
 104
 105 (eval-and-compile
 106   (defconst ruby-here-doc-beg-re
 107   "\\(<\\)<\\(-\\)?\\(\\([a-zA-Z0-9_]+\\)\\|[\"]\\([^\"]+\\)[\"]\\|[']\\([^']+\\)[']\\)"
 108   "Regexp to match the beginning of a heredoc.")
 109
 110   (defconst ruby-expression-expansion-re
 111     "\\(?:[^\\]\\|\\=\\)\\(\\\\\\\\\\)*\\(#\\({[^}\n\\\\]*\\(\\\\.[^}\n\\\\]*\\)*}\\|\\(\\$\\|@\\|@@\\)\\(\\w\\|_\\)+\\)\\)"))
 112
 113 (defun ruby-here-doc-end-match ()
 114   "Return a regexp to find the end of a heredoc.
 115
 116 This should only be called after matching against `ruby-here-doc-beg-re'."
 117   (concat "^"
 118           (if (match-string 2) "[ \t]*" nil)
 119           (regexp-quote
 120            (or (match-string 4)
 121                (match-string 5)
 122                (match-string 6)))))
 123
 124 (defconst ruby-delimiter
 125   (concat "[?$/%(){}#\"'`.:]\\|<<\\|\\[\\|\\]\\|\\_<\\("
 126           ruby-block-beg-re
 127           "\\)\\_>\\|" ruby-block-end-re
 128           "\\|^=begin\\|" ruby-here-doc-beg-re))
 129
 130 (defconst ruby-negative
 131   (concat "^[ \t]*\\(\\(" ruby-block-mid-re "\\)\\>\\|"
 132           ruby-block-end-re "\\|}\\|\\]\\)")
 133   "Regexp to match where the indentation gets shallower.")
 134
 135 (defconst ruby-operator-re "[-,.+*/%&|^~=<>:]\\|\\\\$"
 136   "Regexp to match operators.")
 137
 138 (defconst ruby-symbol-chars "a-zA-Z0-9_"
 139   "List of characters that symbol names may contain.")
 140
 141 (defconst ruby-symbol-re (concat "[" ruby-symbol-chars "]")
 142   "Regexp to match symbols.")
 143
 144 (defvar ruby-use-smie t)
 145
 146 (defvar ruby-mode-map
 147   (let ((map (make-sparse-keymap)))
 148     (unless ruby-use-smie
 149       (define-key map (kbd "M-C-b") 'ruby-backward-sexp)
 150       (define-key map (kbd "M-C-f") 'ruby-forward-sexp)
 151       (define-key map (kbd "M-C-q") 'ruby-indent-exp))
 152     (when ruby-use-smie
 153       (define-key map (kbd "M-C-d") 'smie-down-list))
 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 (easy-menu-define
 161   ruby-mode-menu
 162   ruby-mode-map
 163   "Ruby Mode Menu"
 164   '("Ruby"
 165     ["Beginning of Block" ruby-beginning-of-block t]
 166     ["End of Block" ruby-end-of-block t]
 167     ["Toggle Block" ruby-toggle-block t]
 168     "--"
 169     ["Backward Sexp" ruby-backward-sexp
 170      :visible (not ruby-use-smie)]
 171     ["Backward Sexp" backward-sexp
 172      :visible ruby-use-smie]
 173     ["Forward Sexp" ruby-forward-sexp
 174      :visible (not ruby-use-smie)]
 175     ["Forward Sexp" forward-sexp
 176      :visible ruby-use-smie]
 177     ["Indent Sexp" ruby-indent-exp
 178      :visible (not ruby-use-smie)]
 179     ["Indent Sexp" prog-indent-sexp
 180      :visible ruby-use-smie]))
 181
 182 (defvar ruby-mode-syntax-table
 183   (let ((table (make-syntax-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 ?\n ">" table)
 189     (modify-syntax-entry ?\\ "\\" table)
 190     (modify-syntax-entry ?$ "." table)
 191     (modify-syntax-entry ?? "_" table)
 192     (modify-syntax-entry ?_ "_" table)
 193     (modify-syntax-entry ?: "_" table)
 194     (modify-syntax-entry ?< "." table)
 195     (modify-syntax-entry ?> "." table)
 196     (modify-syntax-entry ?& "." table)
 197     (modify-syntax-entry ?| "." table)
 198     (modify-syntax-entry ?% "." table)
 199     (modify-syntax-entry ?= "." table)
 200     (modify-syntax-entry ?/ "." table)
 201     (modify-syntax-entry ?+ "." table)
 202     (modify-syntax-entry ?* "." table)
 203     (modify-syntax-entry ?- "." table)
 204     (modify-syntax-entry ?\; "." table)
 205     (modify-syntax-entry ?\( "()" table)
 206     (modify-syntax-entry ?\) ")(" table)
 207     (modify-syntax-entry ?\{ "(}" table)
 208     (modify-syntax-entry ?\} "){" table)
 209     (modify-syntax-entry ?\[ "(]" table)
 210     (modify-syntax-entry ?\] ")[" table)
 211     table)
 212   "Syntax table to use in Ruby mode.")
 213
 214 (defcustom ruby-indent-tabs-mode nil
 215   "Indentation can insert tabs in Ruby mode if this is non-nil."
 216   :type 'boolean
 217   :group 'ruby
 218   :safe 'booleanp)
 219
 220 (defcustom ruby-indent-level 2
 221   "Indentation of Ruby statements."
 222   :type 'integer
 223   :group 'ruby
 224   :safe 'integerp)
 225
 226 (defcustom ruby-comment-column (default-value 'comment-column)
 227   "Indentation column of comments."
 228   :type 'integer
 229   :group 'ruby
 230   :safe 'integerp)
 231
 232 (defcustom ruby-deep-arglist t
 233   "Deep indent lists in parenthesis when non-nil.
 234 Also ignores spaces after parenthesis when 'space."
 235   :type 'boolean
 236   :group 'ruby
 237   :safe 'booleanp)
 238
 239 (defcustom ruby-deep-indent-paren '(?\( ?\[ ?\] t)
 240   "Deep indent lists in parenthesis when non-nil.
 241 The value t means continuous line.
 242 Also ignores spaces after parenthesis when 'space."
 243   :group 'ruby)
 244
 245 (defcustom ruby-deep-indent-paren-style 'space
 246   "Default deep indent style."
 247   :options '(t nil space) :group 'ruby)
 248
 249 (defcustom ruby-encoding-map
 250   '((us-ascii       . nil)       ;; Do not put coding: us-ascii
 251     (shift-jis      . cp932)     ;; Emacs charset name of Shift_JIS
 252     (shift_jis      . cp932)     ;; MIME charset name of Shift_JIS
 253     (japanese-cp932 . cp932))    ;; Emacs charset name of CP932
 254   "Alist to map encoding name from Emacs to Ruby.
 255 Associating an encoding name with nil means it needs not be
 256 explicitly declared in magic comment."
 257   :type '(repeat (cons (symbol :tag "From") (symbol :tag "To")))
 258   :group 'ruby)
 259
 260 (defcustom ruby-insert-encoding-magic-comment t
 261   "Insert a magic Emacs 'coding' comment upon save if this is non-nil."
 262   :type 'boolean :group 'ruby)
 263
 264 (defcustom ruby-use-encoding-map t
 265   "Use `ruby-encoding-map' to set encoding magic comment if this is non-nil."
 266   :type 'boolean :group 'ruby)
 267
 268 ;;; SMIE support
 269
 270 (require 'smie)
 271
 272 ;; Here's a simplified BNF grammar, for reference:
 273 ;; http://www.cse.buffalo.edu/~regan/cse305/RubyBNF.pdf
 274 (defconst ruby-smie-grammar
 275   (smie-prec2->grammar
 276    (smie-merge-prec2s
 277     (smie-bnf->prec2
 278      '((id)
 279        (insts (inst) (insts ";" insts))
 280        (inst (exp) (inst "iuwu-mod" exp))
 281        (exp  (exp1) (exp "," exp) (exp "=" exp)
 282              (id " @ " exp)
 283              (exp "." exp))
 284        (exp1 (exp2) (exp2 "?" exp1 ":" exp1))
 285        (exp2 ("def" insts "end")
 286              ("begin" insts-rescue-insts "end")
 287              ("do" insts "end")
 288              ("class" insts "end") ("module" insts "end")
 289              ("for" for-body "end")
 290              ("[" expseq "]")
 291              ("{" hashvals "}")
 292              ("{" insts "}")
 293              ("while" insts "end")
 294              ("until" insts "end")
 295              ("unless" insts "end")
 296              ("if" if-body "end")
 297              ("case"  cases "end"))
 298        (formal-params ("opening-|" exp "|"))
 299        (for-body (for-head ";" insts))
 300        (for-head (id "in" exp))
 301        (cases (exp "then" insts) ;; FIXME: Ruby also allows (exp ":" insts).
 302               (cases "when" cases) (insts "else" insts))
 303        (expseq (exp) );;(expseq "," expseq)
 304        (hashvals (id "=>" exp1) (hashvals "," hashvals))
 305        (insts-rescue-insts (insts)
 306                            (insts-rescue-insts "rescue" insts-rescue-insts)
 307                            (insts-rescue-insts "ensure" insts-rescue-insts))
 308        (itheni (insts) (exp "then" insts))
 309        (ielsei (itheni) (itheni "else" insts))
 310        (if-body (ielsei) (if-body "elsif" if-body)))
 311      '((nonassoc "in") (assoc ";") (right " @ ")
 312        (assoc ",") (right "=") (assoc "."))
 313      '((assoc "when"))
 314      '((assoc "elsif"))
 315      '((assoc "rescue" "ensure"))
 316      '((assoc ",")))
 317
 318     (smie-precs->prec2
 319      '((right "=")
 320        (right "+=" "-=" "*=" "/=" "%=" "**=" "&=" "|=" "^="
 321               "<<=" ">>=" "&&=" "||=")
 322        (left ".." "...")
 323        (left "+" "-")
 324        (left "*" "/" "%" "**")
 325        ;; (left "|") ; FIXME: Conflicts with | after block parameters.
 326        (left "^" "&")
 327        (nonassoc "<=>")
 328        (nonassoc ">" ">=" "<" "<=")
 329        (nonassoc "==" "===" "!=")
 330        (nonassoc "=~" "!~")
 331        (left "<<" ">>")
 332        (left "&&" "||"))))))
 333
 334 (defun ruby-smie--bosp ()
 335   (save-excursion (skip-chars-backward " \t")
 336                   (or (bolp) (memq (char-before) '(?\; ?=)))))
 337
 338 (defun ruby-smie--implicit-semi-p ()
 339   (save-excursion
 340     (skip-chars-backward " \t")
 341     (not (or (bolp)
 342              (and (memq (char-before)
 343                         '(?\; ?- ?+ ?* ?/ ?: ?. ?, ?\[ ?\( ?\{ ?\\ ?& ?> ?< ?% ?~))
 344                   ;; Make sure it's not the end of a regexp.
 345                   (not (eq (car (syntax-after (1- (point)))) 7)))
 346              (and (eq (char-before) ?\?)
 347                   (equal (save-excursion (ruby-smie--backward-token)) "?"))
 348              (and (eq (char-before) ?=)
 349                   (string-match "\\`\\s." (save-excursion
 350                                             (ruby-smie--backward-token))))
 351              (and (eq (car (syntax-after (1- (point)))) 2)
 352                   (equal (save-excursion (ruby-smie--backward-token))
 353                          "iuwu-mod"))
 354              (save-excursion
 355                (forward-comment 1)
 356                (eq (char-after) ?.))))))
 357
 358 (defun ruby-smie--redundant-do-p (&optional skip)
 359   (save-excursion
 360     (if skip (backward-word 1))
 361     (member (nth 2 (smie-backward-sexp ";")) '("while" "until" "for"))))
 362
 363 (defun ruby-smie--opening-pipe-p ()
 364   (save-excursion
 365     (if (eq ?| (char-before)) (forward-char -1))
 366     (skip-chars-backward " \t\n")
 367     (or (eq ?\{ (char-before))
 368         (looking-back "\\_<do" (- (point) 2)))))
 369
 370 (defun ruby-smie--args-separator-p (pos)
 371   (and
 372    (< pos (line-end-position))
 373    (or (eq (char-syntax (preceding-char)) '?w)
 374        ;; FIXME: Check that the preceding token is not a keyword.
 375        ;; This isn't very important most of the time, though.
 376        (and (memq (preceding-char) '(?! ??))
 377             (eq (char-syntax (char-before (1- (point)))) '?w)))
 378    (or (and (eq (char-syntax (char-after pos)) ?w)
 379             (not (looking-at (regexp-opt '("unless" "if" "while" "until"
 380                                            "else" "elsif" "do" "end")
 381                                          'symbols))))
 382        (memq (syntax-after pos) '(7 15))
 383        (save-excursion
 384          (goto-char pos)
 385          (looking-at "\\s(\\|[-+!~:]\\sw")))))
 386
 387 (defun ruby-smie--at-dot-call ()
 388   (and (eq ?w (char-syntax (following-char)))
 389        (eq (char-before) ?.)
 390        (not (eq (char-before (1- (point))) ?.))))
 391
 392 (defun ruby-smie--forward-token ()
 393   (let ((pos (point)))
 394     (skip-chars-forward " \t")
 395     (cond
 396      ((looking-at "\\s\"") ;A heredoc or a string.
 397       (if (not (looking-at "\n"))
 398           ""
 399         ;; Tokenize the whole heredoc as semicolon.
 400         (goto-char (scan-sexps (point) 1))
 401         ";"))
 402      ((and (looking-at "[\n#]")
 403            (ruby-smie--implicit-semi-p)) ;Only add implicit ; when needed.
 404       (if (eolp) (forward-char 1) (forward-comment 1))
 405       ";")
 406      (t
 407       (forward-comment (point-max))
 408       (cond
 409        ((looking-at ":\\s.+")
 410         (goto-char (match-end 0)) (match-string 0)) ;; bug#15208.
 411        ((and (< pos (point))
 412              (save-excursion
 413                (ruby-smie--args-separator-p (prog1 (point) (goto-char pos)))))
 414         " @ ")
 415        (t
 416         (let ((dot (ruby-smie--at-dot-call))
 417               (tok (smie-default-forward-token)))
 418           (when dot
 419             (setq tok (concat "." tok)))
 420           (cond
 421            ((member tok '("unless" "if" "while" "until"))
 422             (if (save-excursion (forward-word -1) (ruby-smie--bosp))
 423                 tok "iuwu-mod"))
 424            ((equal tok "|")
 425             (if (ruby-smie--opening-pipe-p) "opening-|" tok))
 426            ((and (equal tok "") (looking-at "\\\\\n"))
 427             (goto-char (match-end 0)) (ruby-smie--forward-token))
 428            ((equal tok "do")
 429             (cond
 430              ((not (ruby-smie--redundant-do-p 'skip)) tok)
 431              ((> (save-excursion (forward-comment (point-max)) (point))
 432                  (line-end-position))
 433               (ruby-smie--forward-token)) ;Fully redundant.
 434              (t ";")))
 435            (t tok)))))))))
 436
 437 (defun ruby-smie--backward-token ()
 438   (let ((pos (point)))
 439     (forward-comment (- (point)))
 440     (cond
 441      ((and (> pos (line-end-position)) (ruby-smie--implicit-semi-p))
 442       (skip-chars-forward " \t") ";")
 443      ((and (bolp) (not (bobp)))         ;Presumably a heredoc.
 444       ;; Tokenize the whole heredoc as semicolon.
 445       (goto-char (scan-sexps (point) -1))
 446       ";")
 447      ((and (> pos (point)) (not (bolp))
 448            (ruby-smie--args-separator-p pos))
 449       ;; We have "ID SPC ID", which is a method call, but it binds less tightly
 450       ;; than commas, since a method call can also be "ID ARG1, ARG2, ARG3".
 451       ;; In some textbooks, "e1 @ e2" is used to mean "call e1 with arg e2".
 452       " @ ")
 453      (t
 454       (let ((tok (smie-default-backward-token))
 455             (dot (ruby-smie--at-dot-call)))
 456         (when dot
 457           (setq tok (concat "." tok)))
 458         (when (and (eq ?: (char-before)) (string-match "\\`\\s." tok))
 459           (forward-char -1) (setq tok (concat ":" tok))) ;; bug#15208.
 460         (cond
 461          ((member tok '("unless" "if" "while" "until"))
 462           (if (ruby-smie--bosp)
 463               tok "iuwu-mod"))
 464          ((equal tok "|")
 465           (if (ruby-smie--opening-pipe-p) "opening-|" tok))
 466          ((and (equal tok "") (eq ?\\ (char-before)) (looking-at "\n"))
 467           (forward-char -1) (ruby-smie--backward-token))
 468          ((equal tok "do")
 469           (cond
 470            ((not (ruby-smie--redundant-do-p)) tok)
 471            ((> (save-excursion (forward-word 1)
 472                                (forward-comment (point-max)) (point))
 473                (line-end-position))
 474             (ruby-smie--backward-token)) ;Fully redundant.
 475            (t ";")))
 476          (t tok)))))))
 477
 478 (defun ruby-smie-rules (kind token)
 479   (pcase (cons kind token)
 480     (`(:elem . basic) ruby-indent-level)
 481     ;; "foo" "bar" is the concatenation of the two strings, so the second
 482     ;; should be aligned with the first.
 483     (`(:elem . args) (if (looking-at "\\s\"") 0))
 484     ;; (`(:after . ",") (smie-rule-separator kind))
 485     (`(:before . ";")
 486      (cond
 487       ((smie-rule-parent-p "def" "begin" "do" "class" "module" "for"
 488                            "while" "until" "unless"
 489                            "if" "then" "elsif" "else" "when"
 490                            "rescue" "ensure" "{")
 491        (smie-rule-parent ruby-indent-level))
 492       ;; For (invalid) code between switch and case.
 493       ;; (if (smie-parent-p "switch") 4)
 494       ))
 495     (`(:before . ,(or `"(" `"[" `"{"))
 496      (cond
 497       ((and (equal token "{")
 498             (not (smie-rule-prev-p "(" "{" "[" "," "=>" "=" "return" ";")))
 499        ;; Curly block opener.
 500        (smie-rule-parent))
 501       ((smie-rule-hanging-p)
 502        ;; Treat purely syntactic block-constructs as being part of their parent,
 503        ;; when the opening statement is hanging.
 504        (let ((state (smie-backward-sexp 'halfsexp)))
 505          (when (eq t (car state)) (goto-char (cadr state))))
 506        (cons 'column  (smie-indent-virtual)))))
 507     (`(:after . ,(or "=" "iuwu-mod")) 2)
 508     (`(:after . " @ ") (smie-rule-parent))
 509     (`(:before . "do") (smie-rule-parent))
 510     (`(,(or :before :after) . ".")
 511      (unless (smie-rule-parent-p ".")
 512        (smie-rule-parent ruby-indent-level)))
 513     (`(:before . ,(or `"else" `"then" `"elsif" `"rescue" `"ensure")) 0)
 514     (`(:before . ,(or `"when"))
 515      (if (not (smie-rule-sibling-p)) 0)) ;; ruby-indent-level
 516     (`(:after . "+")       ;FIXME: Probably applicable to most infix operators.
 517      (if (smie-rule-parent-p ";") ruby-indent-level))
 518     ))
 519
 520 (defun ruby-imenu-create-index-in-block (prefix beg end)
 521   "Create an imenu index of methods inside a block."
 522   (let ((index-alist '()) (case-fold-search nil)
 523         name next pos decl sing)
 524     (goto-char beg)
 525     (while (re-search-forward "^\\s *\\(\\(class\\s +\\|\\(class\\s *<<\\s *\\)\\|module\\s +\\)\\([^\(<\n ]+\\)\\|\\(def\\|alias\\)\\s +\\([^\(\n ]+\\)\\)" end t)
 526       (setq sing (match-beginning 3))
 527       (setq decl (match-string 5))
 528       (setq next (match-end 0))
 529       (setq name (or (match-string 4) (match-string 6)))
 530       (setq pos (match-beginning 0))
 531       (cond
 532        ((string= "alias" decl)
 533         (if prefix (setq name (concat prefix name)))
 534         (push (cons name pos) index-alist))
 535        ((string= "def" decl)
 536         (if prefix
 537             (setq name
 538                   (cond
 539                    ((string-match "^self\." name)
 540                     (concat (substring prefix 0 -1) (substring name 4)))
 541                   (t (concat prefix name)))))
 542         (push (cons name pos) index-alist)
 543         (ruby-accurate-end-of-block end))
 544        (t
 545         (if (string= "self" name)
 546             (if prefix (setq name (substring prefix 0 -1)))
 547           (if prefix (setq name (concat (substring prefix 0 -1) "::" name)))
 548           (push (cons name pos) index-alist))
 549         (ruby-accurate-end-of-block end)
 550         (setq beg (point))
 551         (setq index-alist
 552               (nconc (ruby-imenu-create-index-in-block
 553                       (concat name (if sing "." "#"))
 554                       next beg) index-alist))
 555         (goto-char beg))))
 556     index-alist))
 557
 558 (defun ruby-imenu-create-index ()
 559   "Create an imenu index of all methods in the buffer."
 560   (nreverse (ruby-imenu-create-index-in-block nil (point-min) nil)))
 561
 562 (defun ruby-accurate-end-of-block (&optional end)
 563   "TODO: document."
 564   (let (state
 565         (end (or end (point-max))))
 566     (while (and (setq state (apply 'ruby-parse-partial end state))
 567                 (>= (nth 2 state) 0) (< (point) end)))))
 568
 569 (defun ruby-mode-variables ()
 570   "Set up initial buffer-local variables for Ruby mode."
 571   (setq indent-tabs-mode ruby-indent-tabs-mode)
 572   (if ruby-use-smie
 573       (smie-setup ruby-smie-grammar #'ruby-smie-rules
 574                   :forward-token  #'ruby-smie--forward-token
 575                   :backward-token #'ruby-smie--backward-token)
 576     (setq-local indent-line-function 'ruby-indent-line))
 577   (setq-local require-final-newline t)
 578   (setq-local comment-start "# ")
 579   (setq-local comment-end "")
 580   (setq-local comment-column ruby-comment-column)
 581   (setq-local comment-start-skip "#+ *")
 582   (setq-local parse-sexp-ignore-comments t)
 583   (setq-local parse-sexp-lookup-properties t)
 584   (setq-local paragraph-start (concat "$\\|" page-delimiter))
 585   (setq-local paragraph-separate paragraph-start)
 586   (setq-local paragraph-ignore-fill-prefix t))
 587
 588 (defun ruby-mode-set-encoding ()
 589   "Insert a magic comment header with the proper encoding if necessary."
 590   (save-excursion
 591     (widen)
 592     (goto-char (point-min))
 593     (when (re-search-forward "[^\0-\177]" nil t)
 594       (goto-char (point-min))
 595       (let ((coding-system
 596              (or save-buffer-coding-system
 597                  buffer-file-coding-system)))
 598         (if coding-system
 599             (setq coding-system
 600                   (or (coding-system-get coding-system 'mime-charset)
 601                       (coding-system-change-eol-conversion coding-system nil))))
 602         (setq coding-system
 603               (if coding-system
 604                   (symbol-name
 605                    (if ruby-use-encoding-map
 606                        (let ((elt (assq coding-system ruby-encoding-map)))
 607                          (if elt (cdr elt) coding-system))
 608                      coding-system))
 609                 "ascii-8bit"))
 610         (when coding-system
 611           (if (looking-at "^#!") (beginning-of-line 2))
 612           (cond ((looking-at "\\s *#.*-\*-\\s *\\(en\\)?coding\\s *:\\s *\\([-a-z0-9_]*\\)\\s *\\(;\\|-\*-\\)")
 613                  (unless (string= (match-string 2) coding-system)
 614                    (goto-char (match-beginning 2))
 615                    (delete-region (point) (match-end 2))
 616                    (and (looking-at "-\*-")
 617                         (let ((n (skip-chars-backward " ")))
 618                           (cond ((= n 0) (insert "  ") (backward-char))
 619                                 ((= n -1) (insert " "))
 620                                 ((forward-char)))))
 621                    (insert coding-system)))
 622                 ((looking-at "\\s *#.*coding\\s *[:=]"))
 623                 (t (when ruby-insert-encoding-magic-comment
 624                      (insert "# -*- coding: " coding-system " -*-\n"))))
 625           (when (buffer-modified-p)
 626             (basic-save-buffer-1)))))))
 627
 628 (defun ruby-current-indentation ()
 629   "Return the indentation level of current line."
 630   (save-excursion
 631     (beginning-of-line)
 632     (back-to-indentation)
 633     (current-column)))
 634
 635 (defun ruby-indent-line (&optional ignored)
 636   "Correct the indentation of the current Ruby line."
 637   (interactive)
 638   (ruby-indent-to (ruby-calculate-indent)))
 639
 640 (defun ruby-indent-to (column)
 641   "Indent the current line to COLUMN."
 642   (when column
 643     (let (shift top beg)
 644       (and (< column 0) (error "invalid nest"))
 645       (setq shift (current-column))
 646       (beginning-of-line)
 647       (setq beg (point))
 648       (back-to-indentation)
 649       (setq top (current-column))
 650       (skip-chars-backward " \t")
 651       (if (>= shift top) (setq shift (- shift top))
 652         (setq shift 0))
 653       (if (and (bolp)
 654                (= column top))
 655           (move-to-column (+ column shift))
 656         (move-to-column top)
 657         (delete-region beg (point))
 658         (beginning-of-line)
 659         (indent-to column)
 660         (move-to-column (+ column shift))))))
 661
 662 (defun ruby-special-char-p (&optional pos)
 663   "Return t if the character before POS is a special character.
 664 If omitted, POS defaults to the current point.
 665 Special characters are `?', `$', `:' when preceded by whitespace,
 666 and `\\' when preceded by `?'."
 667   (setq pos (or pos (point)))
 668   (let ((c (char-before pos)) (b (and (< (point-min) pos)
 669                                       (char-before (1- pos)))))
 670     (cond ((or (eq c ??) (eq c ?$)))
 671           ((and (eq c ?:) (or (not b) (eq (char-syntax b) ? ))))
 672           ((eq c ?\\) (eq b ??)))))
 673
 674 (defun ruby-singleton-class-p (&optional pos)
 675   (save-excursion
 676     (when pos (goto-char pos))
 677     (forward-word -1)
 678     (and (or (bolp) (not (eq (char-before (point)) ?_)))
 679          (looking-at ruby-singleton-class-re))))
 680
 681 (defun ruby-expr-beg (&optional option)
 682   "Check if point is possibly at the beginning of an expression.
 683 OPTION specifies the type of the expression.
 684 Can be one of `heredoc', `modifier', `expr-qstr', `expr-re'."
 685   (save-excursion
 686     (store-match-data nil)
 687     (let ((space (skip-chars-backward " \t"))
 688           (start (point)))
 689       (cond
 690        ((bolp) t)
 691        ((progn
 692           (forward-char -1)
 693           (and (looking-at "\\?")
 694                (or (eq (char-syntax (char-before (point))) ?w)
 695                    (ruby-special-char-p))))
 696         nil)
 697        ((looking-at ruby-operator-re))
 698        ((eq option 'heredoc)
 699         (and (< space 0) (not (ruby-singleton-class-p start))))
 700        ((or (looking-at "[\\[({,;]")
 701             (and (looking-at "[!?]")
 702                  (or (not (eq option 'modifier))
 703                      (bolp)
 704                      (save-excursion (forward-char -1) (looking-at "\\Sw$"))))
 705             (and (looking-at ruby-symbol-re)
 706                  (skip-chars-backward ruby-symbol-chars)
 707                  (cond
 708                   ((looking-at (regexp-opt
 709                                 (append ruby-block-beg-keywords
 710                                         ruby-block-op-keywords
 711                                         ruby-block-mid-keywords)
 712                                 'words))
 713                    (goto-char (match-end 0))
 714                    (not (looking-at "\\s_\\|!")))
 715                   ((eq option 'expr-qstr)
 716                    (looking-at "[a-zA-Z][a-zA-z0-9_]* +%[^ \t]"))
 717                   ((eq option 'expr-re)
 718                    (looking-at "[a-zA-Z][a-zA-z0-9_]* +/[^ \t]"))
 719                   (t nil)))))))))
 720
 721 (defun ruby-forward-string (term &optional end no-error expand)
 722   "TODO: document."
 723   (let ((n 1) (c (string-to-char term))
 724         (re (if expand
 725                 (concat "[^\\]\\(\\\\\\\\\\)*\\([" term "]\\|\\(#{\\)\\)")
 726               (concat "[^\\]\\(\\\\\\\\\\)*[" term "]"))))
 727     (while (and (re-search-forward re end no-error)
 728                 (if (match-beginning 3)
 729                     (ruby-forward-string "}{" end no-error nil)
 730                   (> (setq n (if (eq (char-before (point)) c)
 731                                      (1- n) (1+ n))) 0)))
 732       (forward-char -1))
 733     (cond ((zerop n))
 734           (no-error nil)
 735           ((error "unterminated string")))))
 736
 737 (defun ruby-deep-indent-paren-p (c)
 738   "TODO: document."
 739   (cond ((listp ruby-deep-indent-paren)
 740          (let ((deep (assoc c ruby-deep-indent-paren)))
 741            (cond (deep
 742                   (or (cdr deep) ruby-deep-indent-paren-style))
 743                  ((memq c ruby-deep-indent-paren)
 744                   ruby-deep-indent-paren-style))))
 745         ((eq c ruby-deep-indent-paren) ruby-deep-indent-paren-style)
 746         ((eq c ?\( ) ruby-deep-arglist)))
 747
 748 (defun ruby-parse-partial (&optional end in-string nest depth pcol indent)
 749   "TODO: document throughout function body."
 750   (or depth (setq depth 0))
 751   (or indent (setq indent 0))
 752   (when (re-search-forward ruby-delimiter end 'move)
 753     (let ((pnt (point)) w re expand)
 754       (goto-char (match-beginning 0))
 755       (cond
 756        ((and (memq (char-before) '(?@ ?$)) (looking-at "\\sw"))
 757         (goto-char pnt))
 758        ((looking-at "[\"`]")            ;skip string
 759         (cond
 760          ((and (not (eobp))
 761                (ruby-forward-string (buffer-substring (point) (1+ (point))) end t t))
 762           nil)
 763          (t
 764           (setq in-string (point))
 765           (goto-char end))))
 766        ((looking-at "'")
 767         (cond
 768          ((and (not (eobp))
 769                (re-search-forward "[^\\]\\(\\\\\\\\\\)*'" end t))
 770           nil)
 771          (t
 772           (setq in-string (point))
 773           (goto-char end))))
 774        ((looking-at "/=")
 775         (goto-char pnt))
 776        ((looking-at "/")
 777         (cond
 778          ((and (not (eobp)) (ruby-expr-beg 'expr-re))
 779           (if (ruby-forward-string "/" end t t)
 780               nil
 781             (setq in-string (point))
 782             (goto-char end)))
 783          (t
 784           (goto-char pnt))))
 785        ((looking-at "%")
 786         (cond
 787          ((and (not (eobp))
 788                (ruby-expr-beg 'expr-qstr)
 789                (not (looking-at "%="))
 790                (looking-at "%[QqrxWw]?\\([^a-zA-Z0-9 \t\n]\\)"))
 791           (goto-char (match-beginning 1))
 792           (setq expand (not (memq (char-before) '(?q ?w))))
 793           (setq w (match-string 1))
 794           (cond
 795            ((string= w "[") (setq re "]["))
 796            ((string= w "{") (setq re "}{"))
 797            ((string= w "(") (setq re ")("))
 798            ((string= w "<") (setq re "><"))
 799            ((and expand (string= w "\\"))
 800             (setq w (concat "\\" w))))
 801           (unless (cond (re (ruby-forward-string re end t expand))
 802                         (expand (ruby-forward-string w end t t))
 803                         (t (re-search-forward
 804                             (if (string= w "\\")
 805                                 "\\\\[^\\]*\\\\"
 806                               (concat "[^\\]\\(\\\\\\\\\\)*" w))
 807                             end t)))
 808             (setq in-string (point))
 809             (goto-char end)))
 810          (t
 811           (goto-char pnt))))
 812        ((looking-at "\\?")              ;skip ?char
 813         (cond
 814          ((and (ruby-expr-beg)
 815                (looking-at "?\\(\\\\C-\\|\\\\M-\\)*\\\\?."))
 816           (goto-char (match-end 0)))
 817          (t
 818           (goto-char pnt))))
 819        ((looking-at "\\$")              ;skip $char
 820         (goto-char pnt)
 821         (forward-char 1))
 822        ((looking-at "#")                ;skip comment
 823         (forward-line 1)
 824         (goto-char (point))
 825         )
 826        ((looking-at "[\\[{(]")
 827         (let ((deep (ruby-deep-indent-paren-p (char-after))))
 828           (if (and deep (or (not (eq (char-after) ?\{)) (ruby-expr-beg)))
 829               (progn
 830                 (and (eq deep 'space) (looking-at ".\\s +[^# \t\n]")
 831                      (setq pnt (1- (match-end 0))))
 832                 (setq nest (cons (cons (char-after (point)) pnt) nest))
 833                 (setq pcol (cons (cons pnt depth) pcol))
 834                 (setq depth 0))
 835             (setq nest (cons (cons (char-after (point)) pnt) nest))
 836             (setq depth (1+ depth))))
 837         (goto-char pnt)
 838         )
 839        ((looking-at "[])}]")
 840         (if (ruby-deep-indent-paren-p (matching-paren (char-after)))
 841             (setq depth (cdr (car pcol)) pcol (cdr pcol))
 842           (setq depth (1- depth)))
 843         (setq nest (cdr nest))
 844         (goto-char pnt))
 845        ((looking-at ruby-block-end-re)
 846         (if (or (and (not (bolp))
 847                      (progn
 848                        (forward-char -1)
 849                        (setq w (char-after (point)))
 850                        (or (eq ?_ w)
 851                            (eq ?. w))))
 852                 (progn
 853                   (goto-char pnt)
 854                   (setq w (char-after (point)))
 855                   (or (eq ?_ w)
 856                       (eq ?! w)
 857                       (eq ?? w))))
 858             nil
 859           (setq nest (cdr nest))
 860           (setq depth (1- depth)))
 861         (goto-char pnt))
 862        ((looking-at "def\\s +[^(\n;]*")
 863         (if (or (bolp)
 864                 (progn
 865                   (forward-char -1)
 866                   (not (eq ?_ (char-after (point))))))
 867             (progn
 868               (setq nest (cons (cons nil pnt) nest))
 869               (setq depth (1+ depth))))
 870         (goto-char (match-end 0)))
 871        ((looking-at (concat "\\_<\\(" ruby-block-beg-re "\\)\\_>"))
 872         (and
 873          (save-match-data
 874            (or (not (looking-at "do\\_>"))
 875                (save-excursion
 876                  (back-to-indentation)
 877                  (not (looking-at ruby-non-block-do-re)))))
 878          (or (bolp)
 879              (progn
 880                (forward-char -1)
 881                (setq w (char-after (point)))
 882                (not (or (eq ?_ w)
 883                         (eq ?. w)))))
 884          (goto-char pnt)
 885          (not (eq ?! (char-after (point))))
 886          (skip-chars-forward " \t")
 887          (goto-char (match-beginning 0))
 888          (or (not (looking-at ruby-modifier-re))
 889              (ruby-expr-beg 'modifier))
 890          (goto-char pnt)
 891          (setq nest (cons (cons nil pnt) nest))
 892          (setq depth (1+ depth)))
 893         (goto-char pnt))
 894        ((looking-at ":\\(['\"]\\)")
 895         (goto-char (match-beginning 1))
 896         (ruby-forward-string (match-string 1) end t))
 897        ((looking-at ":\\([-,.+*/%&|^~<>]=?\\|===?\\|<=>\\|![~=]?\\)")
 898         (goto-char (match-end 0)))
 899        ((looking-at ":\\([a-zA-Z_][a-zA-Z_0-9]*[!?=]?\\)?")
 900         (goto-char (match-end 0)))
 901        ((or (looking-at "\\.\\.\\.?")
 902             (looking-at "\\.[0-9]+")
 903             (looking-at "\\.[a-zA-Z_0-9]+")
 904             (looking-at "\\."))
 905         (goto-char (match-end 0)))
 906        ((looking-at "^=begin")
 907         (if (re-search-forward "^=end" end t)
 908             (forward-line 1)
 909           (setq in-string (match-end 0))
 910           (goto-char end)))
 911        ((looking-at "<<")
 912         (cond
 913          ((and (ruby-expr-beg 'heredoc)
 914                (looking-at "<<\\(-\\)?\\(\\([\"'`]\\)\\([^\n]+?\\)\\3\\|\\(?:\\sw\\|\\s_\\)+\\)"))
 915           (setq re (regexp-quote (or (match-string 4) (match-string 2))))
 916           (if (match-beginning 1) (setq re (concat "\\s *" re)))
 917           (let* ((id-end (goto-char (match-end 0)))
 918                  (line-end-position (point-at-eol))
 919                  (state (list in-string nest depth pcol indent)))
 920             ;; parse the rest of the line
 921             (while (and (> line-end-position (point))
 922                         (setq state (apply 'ruby-parse-partial
 923                                            line-end-position state))))
 924             (setq in-string (car state)
 925                   nest (nth 1 state)
 926                   depth (nth 2 state)
 927                   pcol (nth 3 state)
 928                   indent (nth 4 state))
 929             ;; skip heredoc section
 930             (if (re-search-forward (concat "^" re "$") end 'move)
 931                 (forward-line 1)
 932               (setq in-string id-end)
 933               (goto-char end))))
 934          (t
 935           (goto-char pnt))))
 936        ((looking-at "^__END__$")
 937         (goto-char pnt))
 938        ((and (looking-at ruby-here-doc-beg-re)
 939              (boundp 'ruby-indent-point))
 940         (if (re-search-forward (ruby-here-doc-end-match)
 941                                ruby-indent-point t)
 942             (forward-line 1)
 943           (setq in-string (match-end 0))
 944           (goto-char ruby-indent-point)))
 945        (t
 946         (error (format "bad string %s"
 947                        (buffer-substring (point) pnt)
 948                        ))))))
 949   (list in-string nest depth pcol))
 950
 951 (defun ruby-parse-region (start end)
 952   "TODO: document."
 953   (let (state)
 954     (save-excursion
 955       (if start
 956           (goto-char start)
 957         (ruby-beginning-of-indent))
 958       (save-restriction
 959         (narrow-to-region (point) end)
 960         (while (and (> end (point))
 961                     (setq state (apply 'ruby-parse-partial end state))))))
 962     (list (nth 0 state)                 ; in-string
 963           (car (nth 1 state))           ; nest
 964           (nth 2 state)                 ; depth
 965           (car (car (nth 3 state)))     ; pcol
 966           ;(car (nth 5 state))          ; indent
 967           )))
 968
 969 (defun ruby-indent-size (pos nest)
 970   "Return the indentation level in spaces NEST levels deeper than POS."
 971   (+ pos (* (or nest 1) ruby-indent-level)))
 972
 973 (defun ruby-calculate-indent (&optional parse-start)
 974   "Return the proper indentation level of the current line."
 975   ;; TODO: Document body
 976   (save-excursion
 977     (beginning-of-line)
 978     (let ((ruby-indent-point (point))
 979           (case-fold-search nil)
 980           state eol begin op-end
 981           (paren (progn (skip-syntax-forward " ")
 982                         (and (char-after) (matching-paren (char-after)))))
 983           (indent 0))
 984       (if parse-start
 985           (goto-char parse-start)
 986         (ruby-beginning-of-indent)
 987         (setq parse-start (point)))
 988       (back-to-indentation)
 989       (setq indent (current-column))
 990       (setq state (ruby-parse-region parse-start ruby-indent-point))
 991       (cond
 992        ((nth 0 state)                   ; within string
 993         (setq indent nil))              ;  do nothing
 994        ((car (nth 1 state))             ; in paren
 995         (goto-char (setq begin (cdr (nth 1 state))))
 996         (let ((deep (ruby-deep-indent-paren-p (car (nth 1 state)))))
 997           (if deep
 998               (cond ((and (eq deep t) (eq (car (nth 1 state)) paren))
 999                      (skip-syntax-backward " ")
1000                      (setq indent (1- (current-column))))
1001                     ((let ((s (ruby-parse-region (point) ruby-indent-point)))
1002                        (and (nth 2 s) (> (nth 2 s) 0)
1003                             (or (goto-char (cdr (nth 1 s))) t)))
1004                      (forward-word -1)
1005                      (setq indent (ruby-indent-size (current-column)
1006                                                     (nth 2 state))))
1007                     (t
1008                      (setq indent (current-column))
1009                      (cond ((eq deep 'space))
1010                            (paren (setq indent (1- indent)))
1011                            (t (setq indent (ruby-indent-size (1- indent) 1))))))
1012             (if (nth 3 state) (goto-char (nth 3 state))
1013               (goto-char parse-start) (back-to-indentation))
1014             (setq indent (ruby-indent-size (current-column) (nth 2 state))))
1015           (and (eq (car (nth 1 state)) paren)
1016                (ruby-deep-indent-paren-p (matching-paren paren))
1017                (search-backward (char-to-string paren))
1018                (setq indent (current-column)))))
1019        ((and (nth 2 state) (> (nth 2 state) 0)) ; in nest
1020         (if (null (cdr (nth 1 state)))
1021             (error "invalid nest"))
1022         (goto-char (cdr (nth 1 state)))
1023         (forward-word -1)               ; skip back a keyword
1024         (setq begin (point))
1025         (cond
1026          ((looking-at "do\\>[^_]")      ; iter block is a special case
1027           (if (nth 3 state) (goto-char (nth 3 state))
1028             (goto-char parse-start) (back-to-indentation))
1029           (setq indent (ruby-indent-size (current-column) (nth 2 state))))
1030          (t
1031           (setq indent (+ (current-column) ruby-indent-level)))))
1032
1033        ((and (nth 2 state) (< (nth 2 state) 0)) ; in negative nest
1034         (setq indent (ruby-indent-size (current-column) (nth 2 state)))))
1035       (when indent
1036         (goto-char ruby-indent-point)
1037         (end-of-line)
1038         (setq eol (point))
1039         (beginning-of-line)
1040         (cond
1041          ((and (not (ruby-deep-indent-paren-p paren))
1042                (re-search-forward ruby-negative eol t))
1043           (and (not (eq ?_ (char-after (match-end 0))))
1044                (setq indent (- indent ruby-indent-level))))
1045          ((and
1046            (save-excursion
1047              (beginning-of-line)
1048              (not (bobp)))
1049            (or (ruby-deep-indent-paren-p t)
1050                (null (car (nth 1 state)))))
1051           ;; goto beginning of non-empty no-comment line
1052           (let (end done)
1053             (while (not done)
1054               (skip-chars-backward " \t\n")
1055               (setq end (point))
1056               (beginning-of-line)
1057               (if (re-search-forward "^\\s *#" end t)
1058                   (beginning-of-line)
1059                 (setq done t))))
1060           (end-of-line)
1061           ;; skip the comment at the end
1062           (skip-chars-backward " \t")
1063           (let (end (pos (point)))
1064             (beginning-of-line)
1065             (while (and (re-search-forward "#" pos t)
1066                         (setq end (1- (point)))
1067                         (or (ruby-special-char-p end)
1068                             (and (setq state (ruby-parse-region parse-start end))
1069                                  (nth 0 state))))
1070               (setq end nil))
1071             (goto-char (or end pos))
1072             (skip-chars-backward " \t")
1073             (setq begin (if (and end (nth 0 state)) pos (cdr (nth 1 state))))
1074             (setq state (ruby-parse-region parse-start (point))))
1075           (or (bobp) (forward-char -1))
1076           (and
1077            (or (and (looking-at ruby-symbol-re)
1078                     (skip-chars-backward ruby-symbol-chars)
1079                     (looking-at (concat "\\<\\(" ruby-block-hanging-re "\\)\\>"))
1080                     (not (eq (point) (nth 3 state)))
1081                     (save-excursion
1082                       (goto-char (match-end 0))
1083                       (not (looking-at "[a-z_]"))))
1084                (and (looking-at ruby-operator-re)
1085                     (not (ruby-special-char-p))
1086                     (save-excursion
1087                       (forward-char -1)
1088                       (or (not (looking-at ruby-operator-re))
1089                           (not (eq (char-before) ?:))))
1090                     ;; Operator at the end of line.
1091                     (let ((c (char-after (point))))
1092                       (and
1093 ;;                     (or (null begin)
1094 ;;                         (save-excursion
1095 ;;                           (goto-char begin)
1096 ;;                           (skip-chars-forward " \t")
1097 ;;                           (not (or (eolp) (looking-at "#")
1098 ;;                                    (and (eq (car (nth 1 state)) ?{)
1099 ;;                                         (looking-at "|"))))))
1100                        ;; Not a regexp or percent literal.
1101                        (null (nth 0 (ruby-parse-region (or begin parse-start)
1102                                                        (point))))
1103                        (or (not (eq ?| (char-after (point))))
1104                            (save-excursion
1105                              (or (eolp) (forward-char -1))
1106                              (cond
1107                               ((search-backward "|" nil t)
1108                                (skip-chars-backward " \t\n")
1109                                (and (not (eolp))
1110                                     (progn
1111                                       (forward-char -1)
1112                                       (not (looking-at "{")))
1113                                     (progn
1114                                       (forward-word -1)
1115                                       (not (looking-at "do\\>[^_]")))))
1116                               (t t))))
1117                        (not (eq ?, c))
1118                        (setq op-end t)))))
1119            (setq indent
1120                  (cond
1121                   ((and
1122                     (null op-end)
1123                     (not (looking-at (concat "\\<\\(" ruby-block-hanging-re "\\)\\>")))
1124                     (eq (ruby-deep-indent-paren-p t) 'space)
1125                     (not (bobp)))
1126                    (widen)
1127                    (goto-char (or begin parse-start))
1128                    (skip-syntax-forward " ")
1129                    (current-column))
1130                   ((car (nth 1 state)) indent)
1131                   (t
1132                    (+ indent ruby-indent-level))))))))
1133       (goto-char ruby-indent-point)
1134       (beginning-of-line)
1135       (skip-syntax-forward " ")
1136       (if (looking-at "\\.[^.]")
1137           (+ indent ruby-indent-level)
1138         indent))))
1139
1140 (defun ruby-beginning-of-defun (&optional arg)
1141   "Move backward to the beginning of the current defun.
1142 With ARG, move backward multiple defuns.  Negative ARG means
1143 move forward."
1144   (interactive "p")
1145   (let (case-fold-search)
1146     (and (re-search-backward (concat "^\\s *" ruby-defun-beg-re "\\_>")
1147                              nil t (or arg 1))
1148          (beginning-of-line))))
1149
1150 (defun ruby-end-of-defun ()
1151   "Move point to the end of the current defun.
1152 The defun begins at or after the point.  This function is called
1153 by `end-of-defun'."
1154   (interactive "p")
1155   (ruby-forward-sexp)
1156   (let (case-fold-search)
1157     (when (looking-back (concat "^\\s *" ruby-block-end-re))
1158       (forward-line 1))))
1159
1160 (defun ruby-beginning-of-indent ()
1161   "Backtrack to a line which can be used as a reference for
1162 calculating indentation on the lines after it."
1163   (while (and (re-search-backward ruby-indent-beg-re nil 'move)
1164               (if (ruby-in-ppss-context-p 'anything)
1165                   t
1166                 ;; We can stop, then.
1167                 (beginning-of-line)))))
1168
1169 (defun ruby-move-to-block (n)
1170   "Move to the beginning (N < 0) or the end (N > 0) of the
1171 current block, a sibling block, or an outer block.  Do that (abs N) times."
1172   (back-to-indentation)
1173   (let ((signum (if (> n 0) 1 -1))
1174         (backward (< n 0))
1175         (depth (or (nth 2 (ruby-parse-region (point) (line-end-position))) 0))
1176         case-fold-search
1177         down done)
1178     (when (looking-at ruby-block-mid-re)
1179       (setq depth (+ depth signum)))
1180     (when (< (* depth signum) 0)
1181       ;; Moving end -> end or beginning -> beginning.
1182       (setq depth 0))
1183     (dotimes (_ (abs n))
1184       (setq done nil)
1185       (setq down (save-excursion
1186                    (back-to-indentation)
1187                    ;; There is a block start or block end keyword on this
1188                    ;; line, don't need to look for another block.
1189                    (and (re-search-forward
1190                          (if backward ruby-block-end-re
1191                            (concat "\\_<\\(" ruby-block-beg-re "\\)\\_>"))
1192                          (line-end-position) t)
1193                         (not (nth 8 (syntax-ppss))))))
1194       (while (and (not done) (not (if backward (bobp) (eobp))))
1195         (forward-line signum)
1196         (cond
1197          ;; Skip empty and commented out lines.
1198          ((looking-at "^\\s *$"))
1199          ((looking-at "^\\s *#"))
1200          ;; Skip block comments;
1201          ((and (not backward) (looking-at "^=begin\\>"))
1202           (re-search-forward "^=end\\>"))
1203          ((and backward (looking-at "^=end\\>"))
1204           (re-search-backward "^=begin\\>"))
1205          ;; Jump over a multiline literal.
1206          ((ruby-in-ppss-context-p 'string)
1207           (goto-char (nth 8 (syntax-ppss)))
1208           (unless backward
1209             (forward-sexp)
1210             (when (bolp) (forward-char -1)))) ; After a heredoc.
1211          (t
1212           (let ((state (ruby-parse-region (point) (line-end-position))))
1213             (unless (car state) ; Line ends with unfinished string.
1214               (setq depth (+ (nth 2 state) depth))))
1215           (cond
1216            ;; Increased depth, we found a block.
1217            ((> (* signum depth) 0)
1218             (setq down t))
1219            ;; We're at the same depth as when we started, and we've
1220            ;; encountered a block before.  Stop.
1221            ((and down (zerop depth))
1222             (setq done t))
1223            ;; Lower depth, means outer block, can stop now.
1224            ((< (* signum depth) 0)
1225             (setq done t)))))))
1226     (back-to-indentation)))
1227
1228 (defun ruby-beginning-of-block (&optional arg)
1229   "Move backward to the beginning of the current block.
1230 With ARG, move up multiple blocks."
1231   (interactive "p")
1232   (ruby-move-to-block (- (or arg 1))))
1233
1234 (defun ruby-end-of-block (&optional arg)
1235   "Move forward to the end of the current block.
1236 With ARG, move out of multiple blocks."
1237   (interactive "p")
1238   (ruby-move-to-block (or arg 1)))
1239
1240 (defun ruby-forward-sexp (&optional arg)
1241   "Move forward across one balanced expression (sexp).
1242 With ARG, do it many times.  Negative ARG means move backward."
1243   ;; TODO: Document body
1244   (interactive "p")
1245   (cond
1246    (ruby-use-smie (forward-sexp arg))
1247    ((and (numberp arg) (< arg 0)) (ruby-backward-sexp (- arg)))
1248    (t
1249     (let ((i (or arg 1)))
1250       (condition-case nil
1251           (while (> i 0)
1252             (skip-syntax-forward " ")
1253             (if (looking-at ",\\s *") (goto-char (match-end 0)))
1254             (cond ((looking-at "\\?\\(\\\\[CM]-\\)*\\\\?\\S ")
1255                    (goto-char (match-end 0)))
1256                   ((progn
1257                      (skip-chars-forward ",.:;|&^~=!?\\+\\-\\*")
1258                      (looking-at "\\s("))
1259                    (goto-char (scan-sexps (point) 1)))
1260                   ((and (looking-at (concat "\\<\\(" ruby-block-beg-re "\\)\\>"))
1261                         (not (eq (char-before (point)) ?.))
1262                         (not (eq (char-before (point)) ?:)))
1263                    (ruby-end-of-block)
1264                    (forward-word 1))
1265                   ((looking-at "\\(\\$\\|@@?\\)?\\sw")
1266                    (while (progn
1267                             (while (progn (forward-word 1) (looking-at "_")))
1268                             (cond ((looking-at "::") (forward-char 2) t)
1269                                   ((> (skip-chars-forward ".") 0))
1270                                   ((looking-at "\\?\\|!\\(=[~=>]\\|[^~=]\\)")
1271                                    (forward-char 1) nil)))))
1272                   ((let (state expr)
1273                      (while
1274                          (progn
1275                            (setq expr (or expr (ruby-expr-beg)
1276                                           (looking-at "%\\sw?\\Sw\\|[\"'`/]")))
1277                            (nth 1 (setq state (apply 'ruby-parse-partial nil state))))
1278                        (setq expr t)
1279                        (skip-chars-forward "<"))
1280                      (not expr))))
1281             (setq i (1- i)))
1282         ((error) (forward-word 1)))
1283       i))))
1284
1285 (defun ruby-backward-sexp (&optional arg)
1286   "Move backward across one balanced expression (sexp).
1287 With ARG, do it many times.  Negative ARG means move forward."
1288   ;; TODO: Document body
1289   (interactive "p")
1290   (cond
1291    (ruby-use-smie (backward-sexp arg))
1292    ((and (numberp arg) (< arg 0)) (ruby-forward-sexp (- arg)))
1293    (t
1294     (let ((i (or arg 1)))
1295       (condition-case nil
1296           (while (> i 0)
1297             (skip-chars-backward " \t\n,.:;|&^~=!?\\+\\-\\*")
1298             (forward-char -1)
1299             (cond ((looking-at "\\s)")
1300                    (goto-char (scan-sexps (1+ (point)) -1))
1301                    (case (char-before)
1302                      (?% (forward-char -1))
1303                      ((?q ?Q ?w ?W ?r ?x)
1304                       (if (eq (char-before (1- (point))) ?%) (forward-char -2))))
1305                    nil)
1306                   ((looking-at "\\s\"\\|\\\\\\S_")
1307                    (let ((c (char-to-string (char-before (match-end 0)))))
1308                      (while (and (search-backward c)
1309                                  (eq (logand (skip-chars-backward "\\") 1)
1310                                      1))))
1311                    nil)
1312                   ((looking-at "\\s.\\|\\s\\")
1313                    (if (ruby-special-char-p) (forward-char -1)))
1314                   ((looking-at "\\s(") nil)
1315                   (t
1316                    (forward-char 1)
1317                    (while (progn (forward-word -1)
1318                                  (case (char-before)
1319                                    (?_ t)
1320                                    (?. (forward-char -1) t)
1321                                    ((?$ ?@)
1322                                     (forward-char -1)
1323                                     (and (eq (char-before) (char-after)) (forward-char -1)))
1324                                    (?:
1325                                     (forward-char -1)
1326                                     (eq (char-before) :)))))
1327                    (if (looking-at ruby-block-end-re)
1328                        (ruby-beginning-of-block))
1329                    nil))
1330             (setq i (1- i)))
1331         ((error)))
1332       i))))
1333
1334 (defun ruby-indent-exp (&optional ignored)
1335   "Indent each line in the balanced expression following the point."
1336   (interactive "*P")
1337   (let ((here (point-marker)) start top column (nest t))
1338     (set-marker-insertion-type here t)
1339     (unwind-protect
1340         (progn
1341           (beginning-of-line)
1342           (setq start (point) top (current-indentation))
1343           (while (and (not (eobp))
1344                       (progn
1345                         (setq column (ruby-calculate-indent start))
1346                         (cond ((> column top)
1347                                (setq nest t))
1348                               ((and (= column top) nest)
1349                                (setq nest nil) t))))
1350             (ruby-indent-to column)
1351             (beginning-of-line 2)))
1352       (goto-char here)
1353       (set-marker here nil))))
1354
1355 (defun ruby-add-log-current-method ()
1356   "Return the current method name as a string.
1357 This string includes all namespaces.
1358
1359 For example:
1360
1361   #exit
1362   String#gsub
1363   Net::HTTP#active?
1364   File.open
1365
1366 See `add-log-current-defun-function'."
1367   (condition-case nil
1368       (save-excursion
1369         (let* ((indent 0) mname mlist
1370                (start (point))
1371                (make-definition-re
1372                 (lambda (re)
1373                   (concat "^[ \t]*" re "[ \t]+"
1374                           "\\("
1375                           ;; \\. and :: for class methods
1376                           "\\([A-Za-z_]" ruby-symbol-re "*\\|\\.\\|::" "\\)"
1377                           "+\\)")))
1378                (definition-re (funcall make-definition-re ruby-defun-beg-re))
1379                (module-re (funcall make-definition-re "\\(class\\|module\\)")))
1380           ;; Get the current method definition (or class/module).
1381           (when (re-search-backward definition-re nil t)
1382             (goto-char (match-beginning 1))
1383             (if (not (string-equal "def" (match-string 1)))
1384                 (setq mlist (list (match-string 2)))
1385               ;; We're inside the method. For classes and modules,
1386               ;; this check is skipped for performance.
1387               (when (ruby-block-contains-point start)
1388                 (setq mname (match-string 2))))
1389             (setq indent (current-column))
1390             (beginning-of-line))
1391           ;; Walk up the class/module nesting.
1392           (while (and (> indent 0)
1393                       (re-search-backward module-re nil t))
1394             (goto-char (match-beginning 1))
1395             (when (< (current-column) indent)
1396               (setq mlist (cons (match-string 2) mlist))
1397               (setq indent (current-column))
1398               (beginning-of-line)))
1399           ;; Process the method name.
1400           (when mname
1401             (let ((mn (split-string mname "\\.\\|::")))
1402               (if (cdr mn)
1403                   (progn
1404                     (unless (string-equal "self" (car mn)) ; def self.foo
1405                       ;; def C.foo
1406                       (let ((ml (nreverse mlist)))
1407                         ;; If the method name references one of the
1408                         ;; containing modules, drop the more nested ones.
1409                         (while ml
1410                           (if (string-equal (car ml) (car mn))
1411                               (setq mlist (nreverse (cdr ml)) ml nil))
1412                           (or (setq ml (cdr ml)) (nreverse mlist))))
1413                       (if mlist
1414                           (setcdr (last mlist) (butlast mn))
1415                         (setq mlist (butlast mn))))
1416                     (setq mname (concat "." (car (last mn)))))
1417                 ;; See if the method is in singleton class context.
1418                 (let ((in-singleton-class
1419                        (when (re-search-forward ruby-singleton-class-re start t)
1420                          (goto-char (match-beginning 0))
1421                          ;; FIXME: Optimize it out, too?
1422                          ;; This can be slow in a large file, but
1423                          ;; unlike class/module declaration
1424                          ;; indentations, method definitions can be
1425                          ;; intermixed with these, and may or may not
1426                          ;; be additionally indented after visibility
1427                          ;; keywords.
1428                          (ruby-block-contains-point start))))
1429                   (setq mname (concat
1430                                (if in-singleton-class "." "#")
1431                                mname))))))
1432           ;; Generate the string.
1433           (if (consp mlist)
1434               (setq mlist (mapconcat (function identity) mlist "::")))
1435           (if mname
1436               (if mlist (concat mlist mname) mname)
1437             mlist)))))
1438
1439 (defun ruby-block-contains-point (pt)
1440   (save-excursion
1441     (save-match-data
1442       (ruby-forward-sexp)
1443       (> (point) pt))))
1444
1445 (defun ruby-brace-to-do-end (orig end)
1446   (let (beg-marker end-marker)
1447     (goto-char end)
1448     (when (eq (char-before) ?\})
1449       (delete-char -1)
1450       (when (save-excursion
1451               (skip-chars-backward " \t")
1452               (not (bolp)))
1453         (insert "\n"))
1454       (insert "end")
1455       (setq end-marker (point-marker))
1456       (when (and (not (eobp)) (eq (char-syntax (char-after)) ?w))
1457         (insert " "))
1458       (goto-char orig)
1459       (delete-char 1)
1460       (when (eq (char-syntax (char-before)) ?w)
1461         (insert " "))
1462       (insert "do")
1463       (setq beg-marker (point-marker))
1464       (when (looking-at "\\(\\s \\)*|")
1465         (unless (match-beginning 1)
1466           (insert " "))
1467         (goto-char (1+ (match-end 0)))
1468         (search-forward "|"))
1469       (unless (looking-at "\\s *$")
1470         (insert "\n"))
1471       (indent-region beg-marker end-marker)
1472       (goto-char beg-marker)
1473       t)))
1474
1475 (defun ruby-do-end-to-brace (orig end)
1476   (let (beg-marker end-marker beg-pos end-pos)
1477     (goto-char (- end 3))
1478     (when (looking-at ruby-block-end-re)
1479       (delete-char 3)
1480       (setq end-marker (point-marker))
1481       (insert "}")
1482       (goto-char orig)
1483       (delete-char 2)
1484       ;; Maybe this should be customizable, let's see if anyone asks.
1485       (insert "{ ")
1486       (setq beg-marker (point-marker))
1487       (when (looking-at "\\s +|")
1488         (delete-char (- (match-end 0) (match-beginning 0) 1))
1489         (forward-char)
1490         (re-search-forward "|" (line-end-position) t))
1491       (save-excursion
1492         (skip-chars-forward " \t\n\r")
1493         (setq beg-pos (point))
1494         (goto-char end-marker)
1495         (skip-chars-backward " \t\n\r")
1496         (setq end-pos (point)))
1497       (when (or
1498              (< end-pos beg-pos)
1499              (and (= (line-number-at-pos beg-pos) (line-number-at-pos end-pos))
1500                   (< (+ (current-column) (- end-pos beg-pos) 2) fill-column)))
1501         (just-one-space -1)
1502         (goto-char end-marker)
1503         (just-one-space -1))
1504       (goto-char beg-marker)
1505       t)))
1506
1507 (defun ruby-toggle-block ()
1508   "Toggle block type from do-end to braces or back.
1509 The block must begin on the current line or above it and end after the point.
1510 If the result is do-end block, it will always be multiline."
1511   (interactive)
1512   (let ((start (point)) beg end)
1513     (end-of-line)
1514     (unless
1515         (if (and (re-search-backward "\\({\\)\\|\\_<do\\(\\s \\|$\\||\\)")
1516                  (progn
1517                    (setq beg (point))
1518                    (save-match-data (ruby-forward-sexp))
1519                    (setq end (point))
1520                    (> end start)))
1521             (if (match-beginning 1)
1522                 (ruby-brace-to-do-end beg end)
1523               (ruby-do-end-to-brace beg end)))
1524       (goto-char start))))
1525
1526 (eval-and-compile
1527   (defconst ruby-percent-literal-beg-re
1528     "\\(%\\)[qQrswWxIi]?\\([[:punct:]]\\)"
1529     "Regexp to match the beginning of percent literal.")
1530
1531   (defconst ruby-syntax-methods-before-regexp
1532     '("gsub" "gsub!" "sub" "sub!" "scan" "split" "split!" "index" "match"
1533       "assert_match" "Given" "Then" "When")
1534     "Methods that can take regexp as the first argument.
1535 It will be properly highlighted even when the call omits parens.")
1536
1537   (defvar ruby-syntax-before-regexp-re
1538     (concat
1539      ;; Special tokens that can't be followed by a division operator.
1540      "\\(^\\|[[=(,~;<>]"
1541      ;; Distinguish ternary operator tokens.
1542      ;; FIXME: They don't really have to be separated with spaces.
1543      "\\|[?:] "
1544      ;; Control flow keywords and operators following bol or whitespace.
1545      "\\|\\(?:^\\|\\s \\)"
1546      (regexp-opt '("if" "elsif" "unless" "while" "until" "when" "and"
1547                    "or" "not" "&&" "||"))
1548      ;; Method name from the list.
1549      "\\|\\_<"
1550      (regexp-opt ruby-syntax-methods-before-regexp)
1551      "\\)\\s *")
1552     "Regexp to match text that can be followed by a regular expression."))
1553
1554 (defun ruby-syntax-propertize-function (start end)
1555   "Syntactic keywords for Ruby mode.  See `syntax-propertize-function'."
1556   (let (case-fold-search)
1557     (goto-char start)
1558     (remove-text-properties start end '(ruby-expansion-match-data))
1559     (ruby-syntax-propertize-heredoc end)
1560     (ruby-syntax-enclosing-percent-literal end)
1561     (funcall
1562      (syntax-propertize-rules
1563       ;; $' $" $` .... are variables.
1564       ;; ?' ?" ?` are character literals (one-char strings in 1.9+).
1565       ("\\([?$]\\)[#\"'`]"
1566        (1 (unless (save-excursion
1567                     ;; Not within a string.
1568                     (nth 3 (syntax-ppss (match-beginning 0))))
1569             (string-to-syntax "\\"))))
1570       ;; Regular expressions.  Start with matching unescaped slash.
1571       ("\\(?:\\=\\|[^\\]\\)\\(?:\\\\\\\\\\)*\\(/\\)"
1572        (1 (let ((state (save-excursion (syntax-ppss (match-beginning 1)))))
1573             (when (or
1574                    ;; Beginning of a regexp.
1575                    (and (null (nth 8 state))
1576                         (save-excursion
1577                           (forward-char -1)
1578                           (looking-back ruby-syntax-before-regexp-re
1579                                         (point-at-bol))))
1580                    ;; End of regexp.  We don't match the whole
1581                    ;; regexp at once because it can have
1582                    ;; string interpolation inside, or span
1583                    ;; several lines.
1584                    (eq ?/ (nth 3 state)))
1585               (string-to-syntax "\"/")))))
1586       ;; Expression expansions in strings.  We're handling them
1587       ;; here, so that the regexp rule never matches inside them.
1588       (ruby-expression-expansion-re
1589        (0 (ignore (ruby-syntax-propertize-expansion))))
1590       ("^=en\\(d\\)\\_>" (1 "!"))
1591       ("^\\(=\\)begin\\_>" (1 "!"))
1592       ;; Handle here documents.
1593       ((concat ruby-here-doc-beg-re ".*\\(\n\\)")
1594        (7 (unless (or (nth 8 (save-excursion
1595                                (syntax-ppss (match-beginning 0))))
1596                       (ruby-singleton-class-p (match-beginning 0)))
1597             (put-text-property (match-beginning 7) (match-end 7)
1598                                'syntax-table (string-to-syntax "\""))
1599             (ruby-syntax-propertize-heredoc end))))
1600       ;; Handle percent literals: %w(), %q{}, etc.
1601       ((concat "\\(?:^\\|[[ \t\n<+(,=]\\)" ruby-percent-literal-beg-re)
1602        (1 (prog1 "|" (ruby-syntax-propertize-percent-literal end)))))
1603      (point) end)))
1604
1605 (defun ruby-syntax-propertize-heredoc (limit)
1606   (let ((ppss (syntax-ppss))
1607         (res '()))
1608     (when (eq ?\n (nth 3 ppss))
1609       (save-excursion
1610         (goto-char (nth 8 ppss))
1611         (beginning-of-line)
1612         (while (re-search-forward ruby-here-doc-beg-re
1613                                   (line-end-position) t)
1614           (unless (ruby-singleton-class-p (match-beginning 0))
1615             (push (concat (ruby-here-doc-end-match) "\n") res))))
1616       (save-excursion
1617         ;; With multiple openers on the same line, we don't know in which
1618         ;; part `start' is, so we have to go back to the beginning.
1619         (when (cdr res)
1620           (goto-char (nth 8 ppss))
1621           (setq res (nreverse res)))
1622         (while (and res (re-search-forward (pop res) limit 'move))
1623           (if (null res)
1624               (put-text-property (1- (point)) (point)
1625                                  'syntax-table (string-to-syntax "\""))))
1626         ;; End up at bol following the heredoc openers.
1627         ;; Propertize expression expansions from this point forward.
1628         ))))
1629
1630 (defun ruby-syntax-enclosing-percent-literal (limit)
1631   (let ((state (syntax-ppss))
1632         (start (point)))
1633     ;; When already inside percent literal, re-propertize it.
1634     (when (eq t (nth 3 state))
1635       (goto-char (nth 8 state))
1636       (when (looking-at ruby-percent-literal-beg-re)
1637         (ruby-syntax-propertize-percent-literal limit))
1638       (when (< (point) start) (goto-char start)))))
1639
1640 (defun ruby-syntax-propertize-percent-literal (limit)
1641   (goto-char (match-beginning 2))
1642   ;; Not inside a simple string or comment.
1643   (when (eq t (nth 3 (syntax-ppss)))
1644     (let* ((op (char-after))
1645            (ops (char-to-string op))
1646            (cl (or (cdr (aref (syntax-table) op))
1647                    (cdr (assoc op '((?< . ?>))))))
1648            parse-sexp-lookup-properties)
1649       (save-excursion
1650         (condition-case nil
1651             (progn
1652               (if cl              ; Paired delimiters.
1653                   ;; Delimiter pairs of the same kind can be nested
1654                   ;; inside the literal, as long as they are balanced.
1655                   ;; Create syntax table that ignores other characters.
1656                   (with-syntax-table (make-char-table 'syntax-table nil)
1657                     (modify-syntax-entry op (concat "(" (char-to-string cl)))
1658                     (modify-syntax-entry cl (concat ")" ops))
1659                     (modify-syntax-entry ?\\ "\\")
1660                     (save-restriction
1661                       (narrow-to-region (point) limit)
1662                       (forward-list))) ; skip to the paired character
1663                 ;; Single character delimiter.
1664                 (re-search-forward (concat "[^\\]\\(?:\\\\\\\\\\)*"
1665                                            (regexp-quote ops)) limit nil))
1666               ;; Found the closing delimiter.
1667               (put-text-property (1- (point)) (point) 'syntax-table
1668                                  (string-to-syntax "|")))
1669           ;; Unclosed literal, do nothing.
1670           ((scan-error search-failed)))))))
1671
1672 (defun ruby-syntax-propertize-expansion ()
1673   ;; Save the match data to a text property, for font-locking later.
1674   ;; Set the syntax of all double quotes and backticks to punctuation.
1675   (let* ((beg (match-beginning 2))
1676          (end (match-end 2))
1677          (state (and beg (save-excursion (syntax-ppss beg)))))
1678     (when (ruby-syntax-expansion-allowed-p state)
1679       (put-text-property beg (1+ beg) 'ruby-expansion-match-data
1680                          (match-data))
1681       (goto-char beg)
1682       (while (re-search-forward "[\"`]" end 'move)
1683         (put-text-property (match-beginning 0) (match-end 0)
1684                            'syntax-table (string-to-syntax "."))))))
1685
1686 (defun ruby-syntax-expansion-allowed-p (parse-state)
1687   "Return non-nil if expression expansion is allowed."
1688   (let ((term (nth 3 parse-state)))
1689     (cond
1690      ((memq term '(?\" ?` ?\n ?/)))
1691      ((eq term t)
1692       (save-match-data
1693         (save-excursion
1694           (goto-char (nth 8 parse-state))
1695           (looking-at "%\\(?:[QWrxI]\\|\\W\\)")))))))
1696
1697 (defun ruby-syntax-propertize-expansions (start end)
1698   (save-excursion
1699     (goto-char start)
1700     (while (re-search-forward ruby-expression-expansion-re end 'move)
1701       (ruby-syntax-propertize-expansion))))
1702
1703 (defun ruby-in-ppss-context-p (context &optional ppss)
1704   (let ((ppss (or ppss (syntax-ppss (point)))))
1705     (if (cond
1706          ((eq context 'anything)
1707           (or (nth 3 ppss)
1708               (nth 4 ppss)))
1709          ((eq context 'string)
1710           (nth 3 ppss))
1711          ((eq context 'heredoc)
1712           (eq ?\n (nth 3 ppss)))
1713          ((eq context 'non-heredoc)
1714           (and (ruby-in-ppss-context-p 'anything)
1715                (not (ruby-in-ppss-context-p 'heredoc))))
1716          ((eq context 'comment)
1717           (nth 4 ppss))
1718          (t
1719           (error (concat
1720                   "Internal error on `ruby-in-ppss-context-p': "
1721                   "context name `" (symbol-name context) "' is unknown"))))
1722         t)))
1723
1724 (defvar ruby-font-lock-syntax-table
1725   (let ((tbl (copy-syntax-table ruby-mode-syntax-table)))
1726     (modify-syntax-entry ?_ "w" tbl)
1727     tbl)
1728   "The syntax table to use for fontifying Ruby mode buffers.
1729 See `font-lock-syntax-table'.")
1730
1731 (defconst ruby-font-lock-keyword-beg-re "\\(?:^\\|[^.@$]\\|\\.\\.\\)")
1732
1733 (defconst ruby-font-lock-keywords
1734   (list
1735    ;; functions
1736    '("^\\s *def\\s +\\(?:[^( \t\n.]*\\.\\)?\\([^( \t\n]+\\)"
1737      1 font-lock-function-name-face)
1738    ;; keywords
1739    (list (concat
1740           ruby-font-lock-keyword-beg-re
1741           (regexp-opt
1742            '("alias"
1743              "and"
1744              "begin"
1745              "break"
1746              "case"
1747              "class"
1748              "def"
1749              "defined?"
1750              "do"
1751              "elsif"
1752              "else"
1753              "fail"
1754              "ensure"
1755              "for"
1756              "end"
1757              "if"
1758              "in"
1759              "module"
1760              "next"
1761              "not"
1762              "or"
1763              "redo"
1764              "rescue"
1765              "retry"
1766              "return"
1767              "then"
1768              "super"
1769              "unless"
1770              "undef"
1771              "until"
1772              "when"
1773              "while"
1774              "yield")
1775            'symbols))
1776          1 'font-lock-keyword-face)
1777    ;; some core methods
1778    (list (concat
1779           ruby-font-lock-keyword-beg-re
1780           (regexp-opt
1781            '(;; built-in methods on Kernel
1782              "__callee__"
1783              "__dir__"
1784              "__method__"
1785              "abort"
1786              "at_exit"
1787              "autoload"
1788              "autoload?"
1789              "binding"
1790              "block_given?"
1791              "caller"
1792              "catch"
1793              "eval"
1794              "exec"
1795              "exit"
1796              "exit!"
1797              "fail"
1798              "fork"
1799              "format"
1800              "lambda"
1801              "load"
1802              "loop"
1803              "open"
1804              "p"
1805              "print"
1806              "printf"
1807              "proc"
1808              "putc"
1809              "puts"
1810              "raise"
1811              "rand"
1812              "readline"
1813              "readlines"
1814              "require"
1815              "require_relative"
1816              "sleep"
1817              "spawn"
1818              "sprintf"
1819              "srand"
1820              "syscall"
1821              "system"
1822              "throw"
1823              "trap"
1824              "warn"
1825              ;; keyword-like private methods on Module
1826              "alias_method"
1827              "attr"
1828              "attr_accessor"
1829              "attr_reader"
1830              "attr_writer"
1831              "define_method"
1832              "extend"
1833              "include"
1834              "module_function"
1835              "prepend"
1836              "private"
1837              "protected"
1838              "public"
1839              "refine"
1840              "using")
1841            'symbols))
1842          1 'font-lock-builtin-face)
1843    ;; here-doc beginnings
1844    `(,ruby-here-doc-beg-re 0 (unless (ruby-singleton-class-p (match-beginning 0))
1845                                'font-lock-string-face))
1846    ;; Perl-ish keywords
1847    "\\_<\\(?:BEGIN\\|END\\)\\_>\\|^__END__$"
1848    ;; variables
1849    `(,(concat ruby-font-lock-keyword-beg-re
1850               "\\_<\\(nil\\|self\\|true\\|false\\)\\>")
1851      1 font-lock-variable-name-face)
1852    ;; keywords that evaluate to certain values
1853    '("\\_<__\\(?:LINE\\|ENCODING\\|FILE\\)__\\_>" 0 font-lock-variable-name-face)
1854    ;; symbols
1855    '("\\(^\\|[^:]\\)\\(:\\([-+~]@?\\|[/%&|^`]\\|\\*\\*?\\|<\\(<\\|=>?\\)?\\|>[>=]?\\|===?\\|=~\\|![~=]?\\|\\[\\]=?\\|@?\\(\\w\\|_\\)+\\([!?=]\\|\\b_*\\)\\|#{[^}\n\\\\]*\\(\\\\.[^}\n\\\\]*\\)*}\\)\\)"
1856      2 font-lock-constant-face)
1857    ;; variables
1858    '("\\(\\$\\([^a-zA-Z0-9 \n]\\|[0-9]\\)\\)\\W"
1859      1 font-lock-variable-name-face)
1860    '("\\(\\$\\|@\\|@@\\)\\(\\w\\|_\\)+"
1861      0 font-lock-variable-name-face)
1862    ;; constants
1863    '("\\(?:\\_<\\|::\\)\\([A-Z]+\\(\\w\\|_\\)*\\)"
1864      1 (unless (eq ?\( (char-after)) font-lock-type-face))
1865    '("\\(^\\s *\\|[\[\{\(,]\\s *\\|\\sw\\s +\\)\\(\\(\\sw\\|_\\)+\\):[^:]" 2 font-lock-constant-face)
1866    ;; conversion methods on Kernel
1867    (list (concat ruby-font-lock-keyword-beg-re
1868                  (regexp-opt '("Array" "Complex" "Float" "Hash"
1869                                "Integer" "Rational" "String") 'symbols))
1870          1 font-lock-builtin-face)
1871    ;; expression expansion
1872    '(ruby-match-expression-expansion
1873      2 font-lock-variable-name-face t)
1874    ;; negation char
1875    '("[^[:alnum:]_]\\(!\\)[^=]"
1876      1 font-lock-negation-char-face)
1877    ;; character literals
1878    ;; FIXME: Support longer escape sequences.
1879    '("\\_<\\?\\\\?\\S " 0 font-lock-string-face)
1880    )
1881   "Additional expressions to highlight in Ruby mode.")
1882
1883 (defun ruby-match-expression-expansion (limit)
1884   (let* ((prop 'ruby-expansion-match-data)
1885          (pos (next-single-char-property-change (point) prop nil limit))
1886          value)
1887     (when (and pos (> pos (point)))
1888       (goto-char pos)
1889       (or (and (setq value (get-text-property pos prop))
1890                (progn (set-match-data value) t))
1891           (ruby-match-expression-expansion limit)))))
1892
1893 ;;;###autoload
1894 (define-derived-mode ruby-mode prog-mode "Ruby"
1895   "Major mode for editing Ruby code.
1896
1897 \\{ruby-mode-map}"
1898   (ruby-mode-variables)
1899
1900   (setq-local imenu-create-index-function 'ruby-imenu-create-index)
1901   (setq-local add-log-current-defun-function 'ruby-add-log-current-method)
1902   (setq-local beginning-of-defun-function 'ruby-beginning-of-defun)
1903   (setq-local end-of-defun-function 'ruby-end-of-defun)
1904
1905   (add-hook 'after-save-hook 'ruby-mode-set-encoding nil 'local)
1906
1907   (setq-local electric-indent-chars (append '(?\{ ?\}) electric-indent-chars))
1908
1909   (setq-local font-lock-defaults '((ruby-font-lock-keywords) nil nil))
1910   (setq-local font-lock-keywords ruby-font-lock-keywords)
1911   (setq-local font-lock-syntax-table ruby-font-lock-syntax-table)
1912
1913   (setq-local syntax-propertize-function #'ruby-syntax-propertize-function))
1914
1915 ;;; Invoke ruby-mode when appropriate
1916
1917 ;;;###autoload
1918 (add-to-list 'auto-mode-alist
1919              (cons (purecopy (concat "\\(?:\\."
1920                                      "rb\\|ru\\|rake\\|thor"
1921                                      "\\|jbuilder\\|gemspec"
1922                                      "\\|/"
1923                                      "\\(?:Gem\\|Rake\\|Cap\\|Thor"
1924                                      "Vagrant\\|Guard\\)file"
1925                                      "\\)\\'")) 'ruby-mode))
1926
1927 ;;;###autoload
1928 (dolist (name (list "ruby" "rbx" "jruby" "ruby1.9" "ruby1.8"))
1929   (add-to-list 'interpreter-mode-alist (cons (purecopy name) 'ruby-mode)))
1930
1931 (provide 'ruby-mode)
1932
1933 ;;; ruby-mode.el ends here