lisp/find-file.el

   1 ;;; find-file.el --- find a file corresponding to this one given a pattern
   2
   3 ;; Author: Henry Guillaume <henri@tibco.com, henry@c032.aone.net.au>
   4 ;; Maintainer: FSF
   5 ;; Keywords: c, matching, tools
   6
   7 ;; Copyright (C) 1994, 1995, 2001, 2002, 2003, 2004,
   8 ;;   2005, 2006, 2007, 2008 Free Software Foundation, Inc.
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software; you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation; either version 3, or (at your option)
  15 ;; any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  25 ;; Boston, MA 02110-1301, USA.
  26
  27 ;;; Commentary:
  28
  29 ;; PURPOSE:
  30 ;; This package features a function called ff-find-other-file, which performs
  31 ;; the following function:
  32 ;;
  33 ;;     When in a .c file, find the first corresponding .h file in a set
  34 ;;     of directories and display it, and vice-versa from the .h file.
  35 ;;
  36 ;; Many people maintain their include file in a directory separate to their
  37 ;; src directory, and very often you may be editing a file and have a need to
  38 ;; visit the "other file". This package searches through a set of directories
  39 ;; to find that file.
  40 ;;
  41 ;; THE "OTHER FILE", or "corresponding file", generally has the same basename,
  42 ;; and just has a different extension as described by the ff-other-file-alist
  43 ;; variable:
  44 ;;
  45 ;;   '(("\\.cc$"  (".hh" ".h"))
  46 ;;     ("\\.hh$"  (".cc" ".C" ".CC" ".cxx" ".cpp")))
  47 ;;
  48 ;; If the current file has a .cc extension, ff-find-other-file will attempt
  49 ;; to look for a .hh file, and then a .h file in some directory as described
  50 ;; below. The mechanism here is to replace the matched part of the original
  51 ;; filename with each of the corresponding extensions in turn.
  52 ;;
  53 ;; Alternatively, there are situations where the filename of the other file
  54 ;; cannot be determined easily with regexps. For example, a .c file may
  55 ;; have two corresponding .h files, for its public and private parts, or
  56 ;; the filename for the .c file contains part of the pathname of the .h
  57 ;; file, as between src/fooZap.cc and include/FOO/zap.hh. In that case, the
  58 ;; format above can be changed to include a function to be called when the
  59 ;; current file matches the regexp:
  60 ;;
  61 ;;   '(("\\.cc$"  cc--function)
  62 ;;     ("\\.hh$"  hh-function))
  63 ;;
  64 ;; These functions must return a list consisting of the possible names of the
  65 ;; corresponding file, with or without path. There is no real need for more
  66 ;; than one function, and one could imagine the following value for cc-other-
  67 ;; file-alist:
  68 ;;
  69 ;;    (setq cc-other-file-alist
  70 ;;        '(("\\.cc$"  ff-cc-hh-converter)
  71 ;;          ("\\.hh$"  ff-cc-hh-converter)
  72 ;;          ("\\.c$"   (".h"))
  73 ;;          ("\\.h$"   (".c" ".cc" ".C" ".CC" ".cxx" ".cpp"))))
  74 ;;
  75 ;; ff-cc-hh-converter is included at the end of this file as a reference.
  76 ;;
  77 ;; SEARCHING is carried out in a set of directories specified by the
  78 ;; ff-search-directories variable:
  79 ;;
  80 ;;     ("." "../../src" "../include/*" "/usr/local/*/src/*" "$PROJECT/src")
  81 ;;
  82 ;; This means that the corresponding file will be searched for first in
  83 ;; the current directory, then in ../../src, then in one of the directories
  84 ;; under ../include, and so on. The star is _not_ a general wildcard
  85 ;; character: it just indicates that the subdirectories of this directory
  86 ;; must each be searched in turn. Environment variables will be expanded in
  87 ;; the ff-search-directories variable.
  88 ;;
  89 ;; If the point is on a #include line, the file to be #included is searched
  90 ;; for in the same manner. This can be disabled with the ff-ignore-include
  91 ;; variable, or by calling ff-get-other-file instead of ff-find-other-file.
  92 ;;
  93 ;; If the file was not found, ff-find-other-file will prompt you for where
  94 ;; to create the new "corresponding file" (defaults to the current directory),
  95 ;; unless the variable ff-always-try-to-create is set to nil.
  96 ;;
  97 ;; GIVEN AN ARGUMENT (with the ^U prefix), ff-find-other-file will get the
  98 ;; other file in another (the other?) window (see find-file-other-window and
  99 ;; switch-to-buffer-other-window). This can be set on a more permanent basis
 100 ;; by setting ff-always-in-other-window to t in which case the ^U prefix will
 101 ;; do the opposite of what was described above.
 102 ;;
 103 ;; THERE ARE FIVE AVAILABLE HOOKS, called in this order if non-nil:
 104 ;;
 105 ;; - ff-pre-find-hook     - called before the search for the other file starts
 106 ;; - ff-not-found-hook    - called when the other file could not be found
 107 ;; - ff-pre-load-hook     - called just before the other file is 'loaded'
 108 ;; - ff-file-created-hook - called when the other file is created
 109 ;; - ff-post-load-hook    - called just after the other file is 'loaded'
 110 ;;
 111 ;; The *load-hook allow you to place point where you want it in the other
 112 ;; file.
 113
 114 ;; CREDITS:
 115 ;; Many thanks go to TUSC Computer Systems Pty Ltd for providing an environ-
 116 ;; ment that made the development of this package possible.
 117 ;;
 118 ;; Many thanks also go to all those who provided valuable feedback throughout
 119 ;; the development of this package:
 120 ;;     Rolf Ebert in particular, Fritz Knabe, Heddy Boubaker, Sebastian Kremer,
 121 ;;     Vasco Lopes Paulo, Mark A. Plaksin, Robert Lang, Trevor West, Kevin
 122 ;;     Pereira, Benedict Lofstedt & Justin Vallon.
 123
 124 ;;; Code:
 125 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 126 ;; User definable variables:
 127
 128 (defgroup ff nil
 129   "Find a file corresponding to this one given a pattern."
 130   :prefix "ff-"
 131   :link '(emacs-commentary-link "find-file")
 132   :group 'find-file)
 133
 134 (defcustom ff-pre-find-hook nil
 135   "*List of functions to be called before the search for the file starts."
 136   :type 'hook
 137   :group 'ff)
 138
 139 (defcustom ff-pre-load-hook nil
 140   "*List of functions to be called before the other file is loaded."
 141   :type 'hook
 142   :group 'ff)
 143
 144 (defcustom ff-post-load-hook nil
 145   "*List of functions to be called after the other file is loaded."
 146   :type 'hook
 147   :group 'ff)
 148
 149 (defcustom ff-not-found-hook nil
 150   "*List of functions to be called if the other file could not be found."
 151   :type 'hook
 152   :group 'ff)
 153
 154 (defcustom ff-file-created-hook nil
 155   "*List of functions to be called if the other file needs to be created."
 156   :type 'hook
 157   :group 'ff)
 158
 159 (defcustom ff-case-fold-search nil
 160   "*Non-nil means ignore cases in matches (see `case-fold-search').
 161 If you have extensions in different cases, you will want this to be nil."
 162   :type 'boolean
 163   :group 'ff)
 164
 165 (defcustom ff-always-in-other-window nil
 166   "*If non-nil, find the corresponding file in another window by default.
 167 To override this, give an argument to `ff-find-other-file'."
 168   :type 'boolean
 169   :group 'ff)
 170
 171 (defcustom ff-ignore-include nil
 172   "*If non-nil, ignore `#include' lines."
 173   :type 'boolean
 174   :group 'ff)
 175
 176 (defcustom ff-always-try-to-create t
 177   "*If non-nil, always attempt to create the other file if it was not found."
 178   :type 'boolean
 179   :group 'ff)
 180
 181 (defcustom ff-quiet-mode nil
 182   "*If non-nil, trace which directories are being searched."
 183   :type 'boolean
 184   :group 'ff)
 185
 186 ;;;###autoload
 187 (defvar ff-special-constructs
 188   '(
 189     ;; C/C++ include, for NeXTSTEP too
 190     ("^\#\\s *\\(include\\|import\\)\\s +[<\"]\\(.*\\)[>\"]" .
 191      (lambda ()
 192        (buffer-substring (match-beginning 2) (match-end 2))))
 193     )
 194   ;; We include `ff-treat-as-special' documentation here so that autoload
 195   ;; can make it available to be read prior to loading this file.
 196   "*List of special constructs for `ff-treat-as-special' to recognize.
 197 Each element, tried in order, has the form (REGEXP . EXTRACT).
 198 If REGEXP matches the current line (from the beginning of the line),
 199 `ff-treat-as-special' calls function EXTRACT with no args.
 200 If EXTRACT returns nil, keep trying.  Otherwise, return the
 201 filename that EXTRACT returned.")
 202
 203 (defvaralias 'ff-related-file-alist 'ff-other-file-alist)
 204 (defcustom ff-other-file-alist 'cc-other-file-alist
 205   "*Alist of extensions to find given the current file's extension.
 206
 207 This list should contain the most used extensions before the others,
 208 since the search algorithm searches sequentially through each
 209 directory specified in `ff-search-directories'.  If a file is not found,
 210 a new one is created with the first matching extension (`.cc' yields `.hh').
 211 This alist should be set by the major mode."
 212   :type '(choice (repeat (list regexp (choice (repeat string) function)))
 213                  symbol)
 214   :group 'ff)
 215
 216 (defcustom ff-search-directories 'cc-search-directories
 217   "*List of directories to search for a specific file.
 218
 219 Set by default to `cc-search-directories', expanded at run-time.
 220
 221 This list is searched through with each extension specified in
 222 `ff-other-file-alist' that matches this file's extension.  So the
 223 longer the list, the longer it'll take to realize that a file
 224 may not exist.
 225
 226 A typical format is
 227
 228     '(\".\" \"/usr/include\" \"$PROJECT/*/include\")
 229
 230 Environment variables can be inserted between slashes (`/').
 231 They will be replaced by their definition. If a variable does
 232 not exist, it is replaced (silently) with an empty string.
 233
 234 The stars are *not* wildcards: they are searched for together with
 235 the preceding slash.  The star represents all the subdirectories except
 236 `..', and each of these subdirectories will be searched in turn."
 237   :type '(choice (repeat directory) symbol)
 238   :group 'ff)
 239
 240 (defcustom cc-search-directories
 241   '("." "/usr/include" "/usr/local/include/*")
 242   "*See the description of the `ff-search-directories' variable."
 243   :type '(repeat directory)
 244   :group 'ff)
 245
 246 (defcustom cc-other-file-alist
 247   '(("\\.cc\\'"  (".hh" ".h"))
 248     ("\\.hh\\'"  (".cc" ".C"))
 249
 250     ("\\.c\\'"   (".h"))
 251     ("\\.h\\'"   (".c" ".cc" ".C" ".CC" ".cxx" ".cpp"))
 252
 253     ("\\.C\\'"   (".H"  ".hh" ".h"))
 254     ("\\.H\\'"   (".C"  ".CC"))
 255
 256     ("\\.CC\\'"  (".HH" ".H"  ".hh" ".h"))
 257     ("\\.HH\\'"  (".CC"))
 258
 259     ("\\.c\\+\\+\\'" (".h++" ".hh" ".h"))
 260     ("\\.h\\+\\+\\'" (".c++"))
 261
 262     ("\\.cpp\\'" (".hpp" ".hh" ".h"))
 263     ("\\.hpp\\'" (".cpp"))
 264
 265     ("\\.cxx\\'" (".hxx" ".hh" ".h"))
 266     ("\\.hxx\\'" (".cxx")))
 267   "*Alist of extensions to find given the current file's extension.
 268
 269 This list should contain the most used extensions before the others,
 270 since the search algorithm searches sequentially through each directory
 271 specified in `ff-search-directories'.  If a file is not found, a new one
 272 is created with the first matching extension (`.cc' yields `.hh')."
 273   :type '(repeat (list regexp (choice (repeat string) function)))
 274   :group 'ff)
 275
 276 (defcustom modula2-other-file-alist
 277   '(
 278     ("\\.mi$" (".md")) ;; Modula-2 module definition
 279     ("\\.md$" (".mi")) ;; and implementation.
 280     )
 281   "*See the description for the `ff-search-directories' variable."
 282   :type '(repeat (list regexp (choice (repeat string) function)))
 283   :group 'ff)
 284
 285
 286 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 287 ;; No user definable variables beyond this point!
 288 ;; ==============================================
 289
 290 (make-variable-buffer-local 'ff-pre-find-hook)
 291 (make-variable-buffer-local 'ff-pre-load-hook)
 292 (make-variable-buffer-local 'ff-post-load-hook)
 293 (make-variable-buffer-local 'ff-not-found-hook)
 294 (make-variable-buffer-local 'ff-file-created-hook)
 295 (make-variable-buffer-local 'ff-case-fold-search)
 296 (make-variable-buffer-local 'ff-always-in-other-window)
 297 (make-variable-buffer-local 'ff-ignore-include)
 298 (make-variable-buffer-local 'ff-quiet-mode)
 299 (make-variable-buffer-local 'ff-other-file-alist)
 300 (make-variable-buffer-local 'ff-search-directories)
 301
 302 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 303 ;; User entry points
 304
 305 ;;;###autoload
 306 (defun ff-get-other-file (&optional in-other-window)
 307   "Find the header or source file corresponding to this file.
 308 See also the documentation for `ff-find-other-file'.
 309
 310 If optional IN-OTHER-WINDOW is non-nil, find the file in another window."
 311   (interactive "P")
 312   (let ((ignore ff-ignore-include))
 313     (setq ff-ignore-include t)
 314     (ff-find-the-other-file in-other-window)
 315     (setq ff-ignore-include ignore)))
 316
 317 ;;;###autoload
 318 (defalias 'ff-find-related-file 'ff-find-other-file)
 319
 320 ;;;###autoload
 321 (defun ff-find-other-file (&optional in-other-window ignore-include)
 322   "Find the header or source file corresponding to this file.
 323 Being on a `#include' line pulls in that file.
 324
 325 If optional IN-OTHER-WINDOW is non-nil, find the file in the other window.
 326 If optional IGNORE-INCLUDE is non-nil, ignore being on `#include' lines.
 327
 328 Variables of interest include:
 329
 330  - `ff-case-fold-search'
 331    Non-nil means ignore cases in matches (see `case-fold-search').
 332    If you have extensions in different cases, you will want this to be nil.
 333
 334  - `ff-always-in-other-window'
 335    If non-nil, always open the other file in another window, unless an
 336    argument is given to `ff-find-other-file'.
 337
 338  - `ff-ignore-include'
 339    If non-nil, ignores #include lines.
 340
 341  - `ff-always-try-to-create'
 342    If non-nil, always attempt to create the other file if it was not found.
 343
 344  - `ff-quiet-mode'
 345    If non-nil, traces which directories are being searched.
 346
 347  - `ff-special-constructs'
 348    A list of regular expressions specifying how to recognize special
 349    constructs such as include files etc, and an associated method for
 350    extracting the filename from that construct.
 351
 352  - `ff-other-file-alist'
 353    Alist of extensions to find given the current file's extension.
 354
 355  - `ff-search-directories'
 356    List of directories searched through with each extension specified in
 357    `ff-other-file-alist' that matches this file's extension.
 358
 359  - `ff-pre-find-hook'
 360    List of functions to be called before the search for the file starts.
 361
 362  - `ff-pre-load-hook'
 363    List of functions to be called before the other file is loaded.
 364
 365  - `ff-post-load-hook'
 366    List of functions to be called after the other file is loaded.
 367
 368  - `ff-not-found-hook'
 369    List of functions to be called if the other file could not be found.
 370
 371  - `ff-file-created-hook'
 372    List of functions to be called if the other file has been created."
 373   (interactive "P")
 374   (let ((ignore ff-ignore-include))
 375     (setq ff-ignore-include ignore-include)
 376     (ff-find-the-other-file in-other-window)
 377     (setq ff-ignore-include ignore)))
 378
 379 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 380 ;; Support functions
 381
 382 (defun ff-find-the-other-file (&optional in-other-window)
 383   "Find the header or source file corresponding to the current file.
 384 Being on a `#include' line pulls in that file, but see the help on
 385 the `ff-ignore-include' variable.
 386
 387 If optional IN-OTHER-WINDOW is non-nil, find the file in another window."
 388
 389   (let (match           ;; matching regexp for this file
 390         suffixes        ;; set of replacing regexps for the matching regexp
 391         action          ;; function to generate the names of the other files
 392         fname           ;; basename of this file
 393         pos             ;; where we start matching filenames
 394         stub            ;; name of the file without extension
 395         alist           ;; working copy of the list of file extensions
 396         pathname        ;; the pathname of the file or the #include line
 397         default-name    ;; file we should create if none found
 398         format          ;; what we have to match
 399         found           ;; name of the file or buffer found - nil if none
 400         dirs            ;; local value of ff-search-directories
 401         no-match)       ;; whether we know about this kind of file
 402
 403     (run-hooks 'ff-pre-find-hook 'ff-pre-find-hooks)
 404
 405     (message "Working...")
 406
 407     (setq dirs
 408           (if (symbolp ff-search-directories)
 409               (ff-list-replace-env-vars (symbol-value ff-search-directories))
 410             (ff-list-replace-env-vars ff-search-directories)))
 411
 412     (setq fname (ff-treat-as-special))
 413
 414     (cond
 415      ((and (not ff-ignore-include) fname)
 416       (setq default-name fname)
 417       (setq found (ff-get-file dirs fname nil in-other-window)))
 418
 419      ;; let's just get the corresponding file
 420      (t
 421       (setq alist (if (symbolp ff-other-file-alist)
 422                       (symbol-value ff-other-file-alist)
 423                     ff-other-file-alist)
 424             pathname (if (buffer-file-name)
 425                          (buffer-file-name)
 426                        "/none.none"))
 427
 428       (setq fname (file-name-nondirectory pathname)
 429             no-match nil
 430             match (car alist))
 431
 432       ;; find the table entry corresponding to this file
 433       (setq pos (ff-string-match (car match) fname))
 434       (while (and match (if (and pos (>= pos 0)) nil (not pos)))
 435         (setq alist (cdr alist))
 436         (setq match (car alist))
 437         (setq pos (ff-string-match (car match) fname)))
 438
 439       ;; no point going on if we haven't found anything
 440       (if (not match)
 441           (setq no-match t)
 442
 443         ;; otherwise, suffixes contains what we need
 444         (setq suffixes (car (cdr match))
 445               action (car (cdr match))
 446               found nil)
 447
 448         ;; if we have a function to generate new names,
 449         ;; invoke it with the name of the current file
 450         (if (and (atom action) (fboundp action))
 451             (progn
 452               (setq suffixes (funcall action (buffer-file-name))
 453                     match (cons (car match) (list suffixes))
 454                     stub nil
 455                     default-name (car suffixes)))
 456
 457           ;; otherwise build our filename stub
 458           (cond
 459
 460            ;; get around the problem that 0 and nil both mean false!
 461            ((= pos 0)
 462             (setq format "")
 463             (setq stub "")
 464             )
 465
 466            (t
 467             (setq format (concat "\\(.+\\)" (car match)))
 468             (string-match format fname)
 469             (setq stub (substring fname (match-beginning 1) (match-end 1)))
 470             ))
 471
 472           ;; if we find nothing, we should try to get a file like this one
 473           (setq default-name
 474                 (concat stub (car (car (cdr match))))))
 475
 476         ;; do the real work - find the file
 477         (setq found
 478               (ff-get-file dirs
 479                            stub
 480                            suffixes
 481                            in-other-window)))))
 482
 483     (cond
 484      (no-match                     ;; could not even determine the other file
 485       (message ""))
 486
 487      (t
 488       (cond
 489
 490        ((not found)                ;; could not find the other file
 491
 492         (run-hooks 'ff-not-found-hook 'ff-not-found-hooks)
 493
 494         (cond
 495          (ff-always-try-to-create  ;; try to create the file
 496           (let (name pathname)
 497
 498             (setq name
 499                   (expand-file-name
 500                    (read-file-name
 501                     (format "Find or create %s in: " default-name)
 502                     default-directory default-name nil)))
 503
 504             (setq pathname
 505                   (if (file-directory-p name)
 506                       (concat (file-name-as-directory name) default-name)
 507                     (setq found name)))
 508
 509             (ff-find-file pathname in-other-window t)))
 510
 511          (t                        ;; don't create the file, just whinge
 512           (message "No file found for %s" fname))))
 513
 514        (t                          ;; matching file found
 515         nil))))
 516
 517     found))                        ;; return buffer-name or filename
 518
 519 (defun ff-other-file-name ()
 520   "Return name of the header or source file corresponding to the current file.
 521 Being on a `#include' line pulls in that file, but see the help on
 522 the `ff-ignore-include' variable."
 523
 524   (let (match           ;; matching regexp for this file
 525         suffixes        ;; set of replacing regexps for the matching regexp
 526         action          ;; function to generate the names of the other files
 527         fname           ;; basename of this file
 528         pos             ;; where we start matching filenames
 529         stub            ;; name of the file without extension
 530         alist           ;; working copy of the list of file extensions
 531         pathname        ;; the pathname of the file or the #include line
 532         default-name    ;; file we should create if none found
 533         format          ;; what we have to match
 534         found           ;; name of the file or buffer found - nil if none
 535         dirs            ;; local value of ff-search-directories
 536         no-match)       ;; whether we know about this kind of file
 537
 538     (message "Working...")
 539
 540     (setq dirs
 541           (if (symbolp ff-search-directories)
 542               (ff-list-replace-env-vars (symbol-value ff-search-directories))
 543             (ff-list-replace-env-vars ff-search-directories)))
 544
 545     (setq fname (ff-treat-as-special))
 546
 547     (cond
 548      ((and (not ff-ignore-include) fname)
 549       (setq default-name fname)
 550       (setq found (ff-get-file-name dirs fname nil)))
 551
 552      ;; let's just get the corresponding file
 553      (t
 554       (setq alist (if (symbolp ff-other-file-alist)
 555                       (symbol-value ff-other-file-alist)
 556                     ff-other-file-alist)
 557             pathname (if (buffer-file-name)
 558                          (buffer-file-name)
 559                        "/none.none"))
 560
 561       (setq fname (file-name-nondirectory pathname)
 562             no-match nil
 563             match (car alist))
 564
 565       ;; find the table entry corresponding to this file
 566       (setq pos (ff-string-match (car match) fname))
 567       (while (and match (if (and pos (>= pos 0)) nil (not pos)))
 568         (setq alist (cdr alist))
 569         (setq match (car alist))
 570         (setq pos (ff-string-match (car match) fname)))
 571
 572       ;; no point going on if we haven't found anything
 573       (if (not match)
 574           (setq no-match t)
 575
 576         ;; otherwise, suffixes contains what we need
 577         (setq suffixes (car (cdr match))
 578               action (car (cdr match))
 579               found nil)
 580
 581         ;; if we have a function to generate new names,
 582         ;; invoke it with the name of the current file
 583         (if (and (atom action) (fboundp action))
 584             (progn
 585               (setq suffixes (funcall action (buffer-file-name))
 586                     match (cons (car match) (list suffixes))
 587                     stub nil
 588                     default-name (car suffixes)))
 589
 590           ;; otherwise build our filename stub
 591           (cond
 592
 593            ;; get around the problem that 0 and nil both mean false!
 594            ((= pos 0)
 595             (setq format "")
 596             (setq stub "")
 597             )
 598
 599            (t
 600             (setq format (concat "\\(.+\\)" (car match)))
 601             (string-match format fname)
 602             (setq stub (substring fname (match-beginning 1) (match-end 1)))
 603             ))
 604
 605           ;; if we find nothing, we should try to get a file like this one
 606           (setq default-name
 607                 (concat stub (car (car (cdr match))))))
 608
 609         ;; do the real work - find the file
 610         (setq found
 611               (ff-get-file-name dirs stub suffixes)))))
 612     found))                        ;; return buffer-name or filename
 613
 614 (defun ff-get-file (search-dirs filename &optional suffix-list other-window)
 615   "Find a file in the SEARCH-DIRS with the given FILENAME (or filename stub).
 616 If (optional) SUFFIX-LIST is nil, search for fname, otherwise search
 617 for fname with each of the given suffixes.  Get the file or the buffer
 618 corresponding to the name of the first file found, or nil."
 619   (let ((filename (ff-get-file-name search-dirs filename suffix-list)))
 620
 621     (cond
 622      ((not filename)
 623       nil)
 624
 625      ((bufferp (get-file-buffer filename))
 626       (ff-switch-to-buffer (get-file-buffer filename) other-window)
 627       filename)
 628
 629      ((file-exists-p filename)
 630       (ff-find-file filename other-window nil)
 631       filename)
 632
 633      (t
 634       nil))))
 635
 636 (defun ff-get-file-name (search-dirs fname-stub &optional suffix-list)
 637   "Find a file in SEARCH-DIRS with the given name (or stub) FNAME-STUB.
 638 If (optional) SUFFIX-LIST is nil, search for FNAME-STUB, otherwise
 639 search for FNAME-STUB with each of the given suffixes.  Return the
 640 name of the first file found."
 641   (let* (dirs         ;; working copy of dirs to search
 642          dir          ;; the current dir considered
 643          file         ;; filename being looked for
 644          rest         ;; pathname after first /*
 645          this-suffix  ;; the suffix we are currently considering
 646          suffixes     ;; working copy of suffix-list
 647          filename     ;; built filename
 648          blist        ;; list of live buffers
 649          buf          ;; current buffer in blist
 650          found)       ;; whether we have found anything
 651
 652     (setq suffixes suffix-list)
 653
 654     ;; suffixes is nil => fname-stub is the file we are looking for
 655     ;; otherwise fname-stub is a stub, and we append a suffix
 656     (if suffixes
 657         (setq this-suffix (car suffixes))
 658       (setq this-suffix "")
 659       (setq suffixes (list "")))
 660
 661     ;; find whether the file is in a buffer first
 662     (while (and suffixes (not found))
 663       (setq filename (concat fname-stub this-suffix))
 664
 665       (if (not ff-quiet-mode)
 666           (message "Finding buffer %s..." filename))
 667
 668       (if (bufferp (get-file-buffer filename))
 669           (setq found (buffer-file-name (get-file-buffer filename))))
 670
 671       (setq blist (buffer-list))
 672       (setq buf (buffer-name (car blist)))
 673       (while (and blist (not found))
 674
 675         (if (string-match (concat filename "<[0-9]+>") buf)
 676             (setq found (buffer-file-name (car blist))))
 677
 678         (setq blist (cdr blist))
 679         (setq buf (buffer-name (car blist))))
 680
 681       (setq suffixes (cdr suffixes))
 682       (setq this-suffix (car suffixes)))
 683
 684     ;; now look for the real file
 685     (setq dirs search-dirs)
 686     (setq dir  (car dirs))
 687     (while (and (not found) dirs)
 688
 689       (setq suffixes suffix-list)
 690
 691       ;; if dir does not contain '/*', look for the file
 692       (if (and dir (not (string-match "\\([^*]*\\)/\\\*\\(/.*\\)*" dir)))
 693           (progn
 694
 695             ;; suffixes is nil => fname-stub is the file we are looking for
 696             ;; otherwise fname-stub is a stub, and we append a suffix
 697             (if suffixes
 698                 (setq this-suffix (car suffixes))
 699               (setq this-suffix "")
 700               (setq suffixes (list "")))
 701
 702             (while (and suffixes (not found))
 703
 704               (setq filename (concat fname-stub this-suffix))
 705               (setq file (concat dir "/" filename))
 706
 707               (if (not ff-quiet-mode)
 708                   (message "Finding %s..." file))
 709
 710               (if (file-exists-p file)
 711                   (setq found file))
 712
 713               (setq suffixes (cdr suffixes))
 714               (setq this-suffix (car suffixes))))
 715
 716         ;; otherwise dir matches the '/*', so search each dir separately
 717         (progn
 718           (if (match-beginning 2)
 719               (setq rest (substring dir (match-beginning 2) (match-end 2)))
 720             (setq rest "")
 721             )
 722           (setq dir  (substring dir (match-beginning 1) (match-end 1)))
 723
 724           (let ((dirlist (ff-all-dirs-under dir '("..")))
 725                 this-dir compl-dirs)
 726
 727             (setq this-dir (car dirlist))
 728             (while dirlist
 729               (setq compl-dirs
 730                     (append
 731                      compl-dirs
 732                      (list (concat this-dir rest))
 733                      ))
 734               (setq dirlist  (cdr dirlist))
 735               (setq this-dir (car dirlist)))
 736
 737             (if compl-dirs
 738                 (setq found (ff-get-file-name compl-dirs
 739                                               fname-stub
 740                                               suffix-list))))))
 741       (setq dirs (cdr dirs))
 742       (setq dir (car dirs)))
 743
 744     (if found
 745         (message "%s found" found))
 746
 747     found))
 748
 749 (defun ff-string-match (regexp string &optional start)
 750   "Like `string-match', but set `case-fold-search' temporarily.
 751 The value used comes from `ff-case-fold-search'."
 752   (let ((case-fold-search ff-case-fold-search))
 753     (if regexp
 754         (string-match regexp string start))))
 755
 756 (defun ff-list-replace-env-vars (search-list)
 757   "Replace environment variables (of the form $VARIABLE) in SEARCH-LIST."
 758   (let (list
 759         (var (car search-list)))
 760     (while search-list
 761       (if (string-match "\\(.*\\)\\$[({]*\\([a-zA-Z0-9_]+\\)[)}]*\\(.*\\)" var)
 762           (setq var
 763                 (concat
 764                  (substring var (match-beginning 1) (match-end 1))
 765                  (getenv (substring var (match-beginning 2) (match-end 2)))
 766                  (substring var (match-beginning 3) (match-end 3)))))
 767       (setq search-list (cdr search-list))
 768       (setq list (cons var list))
 769       (setq var (car search-list)))
 770     (setq search-list (reverse list))))
 771
 772 (defun ff-treat-as-special ()
 773   "Return the file to look for if the construct was special, else nil.
 774 See variable `ff-special-constructs'."
 775   (save-excursion
 776     (beginning-of-line 1)
 777     (let* (fname
 778            (list ff-special-constructs)
 779            (elem (car list))
 780            (regexp (car elem))
 781            (match (cdr elem)))
 782       (while (and list (not fname))
 783         (if (and (looking-at regexp) match)
 784             (setq fname (funcall match)))
 785         (setq list (cdr list))
 786         (setq elem (car list))
 787         (setq regexp (car elem))
 788         (setq match (cdr elem)))
 789       fname)))
 790
 791 (defun ff-basename (string)
 792   "Return the basename of pathname STRING."
 793   (setq string (concat "/" string))
 794   (string-match ".*/\\([^/]+\\)$" string)
 795   (setq string (substring string (match-beginning 1) (match-end 1))))
 796
 797 (defun ff-all-dirs-under (here &optional exclude)
 798   "Get all the directory files under directory HERE.
 799 Exclude all files in the optional EXCLUDE list."
 800   (if (file-directory-p here)
 801       (condition-case nil
 802           (progn
 803             (let ((files (directory-files here t))
 804                   (dirlist (list))
 805                   file)
 806               (while files
 807                 (setq file (car files))
 808                 (if (and
 809                      (file-directory-p file)
 810                      (not (member (ff-basename file) exclude)))
 811                     (setq dirlist (cons file dirlist)))
 812                 (setq files (cdr files)))
 813               (setq dirlist (reverse dirlist))))
 814         (error nil))
 815     nil))
 816
 817 (defun ff-switch-file (f1 f2 file &optional in-other-window new-file)
 818   "Call F1 or F2 on FILE, according to IN-OTHER-WINDOW.
 819 In addition, this runs various hooks.
 820
 821 Either F1 or F2 receives FILE as the sole argument.
 822 The decision of which one to call is based on IN-OTHER-WINDOW
 823 and on the global variable `ff-always-in-other-window'.
 824
 825 F1 and F2 are typically `find-file' / `find-file-other-window'
 826 or `switch-to-buffer' / `switch-to-buffer-other-window' function pairs.
 827
 828 If optional NEW-FILE is t, then a special hook (`ff-file-created-hook') is
 829 called before `ff-post-load-hook'."
 830   (run-hooks 'ff-pre-load-hook 'ff-pre-load-hooks)
 831   (if (or
 832        (and in-other-window (not ff-always-in-other-window))
 833        (and (not in-other-window) ff-always-in-other-window))
 834       (funcall f2 file)
 835     (funcall f1 file))
 836   (if new-file
 837       (run-hooks 'ff-file-created-hook 'ff-file-created-hooks))
 838   (run-hooks 'ff-post-load-hook 'ff-post-load-hooks))
 839
 840 (defun ff-find-file (file &optional in-other-window new-file)
 841   "Like `find-file', but may show the file in another window."
 842   (ff-switch-file 'find-file
 843                   'find-file-other-window
 844                   file in-other-window new-file))
 845
 846 (defun ff-switch-to-buffer (buffer-or-name &optional in-other-window)
 847   "Like `switch-to-buffer', but may show the buffer in another window."
 848
 849   (ff-switch-file 'switch-to-buffer
 850                   'switch-to-buffer-other-window
 851                   buffer-or-name in-other-window nil))
 852
 853 ;;;###autoload
 854 (defun ff-mouse-find-other-file (event)
 855   "Visit the file you click on."
 856   (interactive "e")
 857   (save-excursion
 858     (mouse-set-point event)
 859     (ff-find-other-file nil)))
 860
 861 ;;;###autoload
 862 (defun ff-mouse-find-other-file-other-window (event)
 863   "Visit the file you click on in another window."
 864   (interactive "e")
 865   (save-excursion
 866     (mouse-set-point event)
 867     (ff-find-other-file t)))
 868
 869 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 870 ;; This section offers an example of user defined function to select files
 871
 872 (defun ff-upcase-p (string &optional start end)
 873   "Return t if STRING is all uppercase.
 874 Given START and/or END, checks between these characters."
 875   (let (match str)
 876     (if (not start)
 877         (setq start 0))
 878     (if (not end)
 879         (setq end (length string)))
 880     (if (= start end)
 881         (setq end (1+ end)))
 882     (setq str (substring string start end))
 883     (if (and
 884          (ff-string-match "[A-Z]+" str)
 885          (setq match (match-data))
 886          (= (car match) 0)
 887          (= (car (cdr match)) (length str)))
 888         t
 889       nil)))
 890
 891 (defun ff-cc-hh-converter (arg)
 892   "Discriminate file extensions.
 893 Build up a new file list based possibly on part of the directory name
 894 and the name of the file passed in."
 895   (ff-string-match "\\(.*\\)/\\([^/]+\\)/\\([^.]+\\).\\([^/]+\\)$" arg)
 896   (let ((path (if (match-beginning 1)
 897                   (substring arg (match-beginning 1) (match-end 1)) nil))
 898         (dire (if (match-beginning 2)
 899                   (substring arg (match-beginning 2) (match-end 2)) nil))
 900         (file (if (match-beginning 3)
 901                   (substring arg (match-beginning 3) (match-end 3)) nil))
 902         (extn (if (match-beginning 4)
 903                   (substring arg (match-beginning 4) (match-end 4)) nil))
 904         return-list)
 905     (cond
 906      ;; fooZapJunk.cc => ZapJunk.{hh,h} or fooZapJunk.{hh,h}
 907      ((and (string= extn "cc")
 908            (ff-string-match "^\\([a-z]+\\)\\([A-Z].+\\)$" file))
 909       (let ((stub  (substring file (match-beginning 2) (match-end 2))))
 910         (setq dire (upcase (substring file (match-beginning 1) (match-end 1))))
 911         (setq return-list (list (concat stub ".hh")
 912                                 (concat stub ".h")
 913                                 (concat file ".hh")
 914                                 (concat file ".h")))
 915         ))
 916      ;; FOO/ZapJunk.hh => fooZapJunk.{cc,C} or ZapJunk.{cc,C}
 917      ((and (string= extn "hh") (ff-upcase-p dire) file)
 918       (let ((stub (concat (downcase dire) file)))
 919         (setq return-list (list (concat stub ".cc")
 920                                 (concat stub ".C")
 921                                 (concat file ".cc")
 922                                 (concat file ".C")))
 923         ))
 924      ;; zap.cc => zap.hh or zap.h
 925      ((string= extn "cc")
 926       (let ((stub file))
 927         (setq return-list (list (concat stub ".hh")
 928                                 (concat stub ".h")))
 929         ))
 930      ;; zap.hh => zap.cc or zap.C
 931      ((string= extn "hh")
 932       (let ((stub file))
 933         (setq return-list (list (concat stub ".cc")
 934                                 (concat stub ".C")))
 935         ))
 936      (t
 937       nil))
 938
 939     return-list))
 940
 941 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 942 ;; This section offers an example of user defined function to place point.
 943 ;; The regexps are Ada specific.
 944
 945 (defvar ff-function-name nil "Name of the function we are in.")
 946
 947 ;; bind with (setq ff-pre-load-hook 'ff-which-function-are-we-in)
 948 ;;
 949 (defvar ada-procedure-start-regexp)
 950 (defvar ada-package-start-regexp)
 951
 952 (defun ff-which-function-are-we-in ()
 953   "Return the name of the function whose definition/declaration point is in.
 954 Also remember that name in `ff-function-name'."
 955   (setq ff-function-name
 956         (save-excursion
 957           (if (or (re-search-backward ada-procedure-start-regexp nil t)
 958                   (re-search-backward ada-package-start-regexp nil t))
 959               (match-string 0)))))
 960
 961 ;; bind with (setq ff-post-load-hook 'ff-set-point-accordingly)
 962 ;;
 963 (defun ff-set-point-accordingly ()
 964   "Find the function specified in `ff-function-name'.
 965 That name was previously determined by `ff-which-function-are-we-in'."
 966   (if ff-function-name
 967       (progn
 968         (goto-char (point-min))
 969         (search-forward ff-function-name nil t))))
 970
 971 (provide 'find-file)
 972
 973 ;; arch-tag: 5a2fc49e-3b0a-4708-9acf-fb14e471a97a
 974 ;;; find-file.el ends here