[PATCH 1/2] Merge subword-mode and capitalized-words-mode

[Daniel Colascione]

subword-mode began life as part of cc-mode, but because it's
generally useful, it was extracted and made a generic part of
Emacs.  subword-mode uses command remapping to achive its subword
motion, however, and this mechanism can't catch all kinds of word-
based motion, resulting in inconsistency.

capitalized-words-mode attempts to do what subword-mode does, but
using a hook added to C core for the purpose.  This hook allows
capitalizd-words-mode to change all kinds of word-based motion
into subword motion.  Unfortunately, capitalized-words-mode used
overly simplistic code that caused it to fail to properly move
over words like "fooBarBAZ"; subword-mode handles these words
properly.  capitalized-words-mode is also disadvantaged by
a long and misleading name.

This patch merges subword-mode and capitalized-words-mode by
modifying subword-mode to use the core hook and marking
capitalized-words-mode as an obsolete alias for subword-mode.

This patch also includes an automated test for subword motion.
---
 lisp/progmodes/cap-words.el |   98 -------------------------------------------
 lisp/progmodes/subword.el   |   88 +++++++++++++++++++++-----------------
 test/automated/subword.el   |   58 +++++++++++++++++++++++++
 3 files changed, 106 insertions(+), 138 deletions(-)
 delete mode 100644 lisp/progmodes/cap-words.el
 create mode 100644 test/automated/subword.el

diff --git a/lisp/progmodes/cap-words.el b/lisp/progmodes/cap-words.el
deleted file mode 100644
index 6d4d9f0..0000000
--- a/lisp/progmodes/cap-words.el
+++ /dev/null
@@ -1,98 +0,0 @@
-;;; cap-words.el --- minor mode for motion in CapitalizedWordIdentifiers
-
-;; Copyright (C) 2002-2012  Free Software Foundation, Inc.
-
-;; Author: Dave Love <address@hidden>
-;; Keywords: languages
-
-;; This file is part of GNU Emacs.
-
-;; GNU Emacs is free software: you can redistribute it and/or modify
-;; it under the terms of the GNU General Public License as published by
-;; the Free Software Foundation, either version 3 of the License, or
-;; (at your option) any later version.
-
-;; GNU Emacs is distributed in the hope that it will be useful,
-;; but WITHOUT ANY WARRANTY; without even the implied warranty of
-;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-;; GNU General Public License for more details.
-
-;; You should have received a copy of the GNU General Public License
-;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
-
-;;; Commentary:
-
-;; Provides Capitalized Words minor mode for word movement in
-;; identifiers CapitalizedLikeThis.
-
-;; Note that the same effect could be obtained by frobbing the
-;; category of upper case characters to produce word boundaries, but
-;; the necessary processing isn't done for ASCII characters.
-
-;; Fixme: This doesn't work properly for mouse double clicks.
-
-;;; Code:
-
-(defun capitalized-find-word-boundary (pos limit)
-  "Function for use in `find-word-boundary-function-table'.
-Looks for word boundaries before capitals."
-  (save-excursion
-    (goto-char pos)
-    (let (case-fold-search)
-      (if (<= pos limit)
-         ;; Fixme: Are these regexps the best?
-         (or (and (re-search-forward "\\=.\\w*[[:upper:]]"
-                                     limit t)
-                  (progn (backward-char)
-                         t))
-             (re-search-forward "\\>" limit t))
-       (or (re-search-backward "[[:upper:]]\\w*\\=" limit t)
-           (re-search-backward "\\<" limit t))))
-    (point)))
-
-
-(defconst capitalized-find-word-boundary-function-table
-  (let ((tab (make-char-table nil)))
-    (set-char-table-range tab t #'capitalized-find-word-boundary)
-    tab)
-  "Assigned to `find-word-boundary-function-table' in Capitalized Words mode.")
-
-;;;###autoload
-(define-minor-mode capitalized-words-mode
-  "Toggle Capitalized Words mode.
-With a prefix argument ARG, enable Capitalized Words mode if ARG
-is positive, and disable it otherwise.  If called from Lisp,
-enable the mode if ARG is omitted or nil.
-
-Capitalized Words mode is a buffer-local minor mode.  When
-enabled, a word boundary occurs immediately before an uppercase
-letter in a symbol.  This is in addition to all the normal
-boundaries given by the syntax and category tables.  There is no
-restriction to ASCII.
-
-E.g. the beginning of words in the following identifier are as marked:
-
-  capitalizedWorDD
-  ^          ^  ^^
-
-Note that these word boundaries only apply for word motion and
-marking commands such as \\[forward-word].  This mode does not affect word
-boundaries found by regexp matching (`\\>', `\\w' &c).
-
-This style of identifiers is common in environments like Java ones,
-where underscores aren't trendy enough.  Capitalization rules are
-sometimes part of the language, e.g. Haskell, which may thus encourage
-such a style.  It is appropriate to add `capitalized-words-mode' to
-the mode hook for programming language modes in which you encounter
-variables like this, e.g. `java-mode-hook'.  It's unlikely to cause
-trouble if such identifiers aren't used.
-
-See also `glasses-mode' and `studlify-word'.
-Obsoletes `c-forward-into-nomenclature'."
-  nil " Caps" nil :group 'programming
-  (set (make-local-variable 'find-word-boundary-function-table)
-       capitalized-find-word-boundary-function-table))
-
-(provide 'cap-words)
-
-;;; cap-words.el ends here
diff --git a/lisp/progmodes/subword.el b/lisp/progmodes/subword.el
index 7d8dd43..735beb0 100644
--- a/lisp/progmodes/subword.el
+++ b/lisp/progmodes/subword.el
@@ -1,4 +1,4 @@
-;;; subword.el --- Handling capitalized subwords in a nomenclature
+;;; subword.el --- Handling capitalized subwords in a nomenclature -*- 
lexical-binding: t -*-
 
 ;; Copyright (C) 2004-2012 Free Software Foundation, Inc.
 
@@ -25,8 +25,11 @@
 ;; useful in general and not tied to C and c-mode at all.
 
 ;; This package provides `subword' oriented commands and a minor mode
-;; (`subword-mode') that substitutes the common word handling
-;; functions with them.
+;; (`subword-mode') that changes the definition of a "word" so that
+;; Emacs will see subword bounaries as word boundaries in normal
+;; movement commands.  Previously, `subword-mode' substituted the
+;; normal word-movement commands with the subword-oriented versions at
+;; the keymap level.
 
 ;; In spite of GNU Coding Standards, it is popular to name a symbol by
 ;; mixing uppercase and lowercase letters, e.g. "GtkWidget",
@@ -45,25 +48,6 @@
 ;; subwords in a nomenclature to move between them and to edit them as
 ;; words.
 
-;; In the minor mode, all common key bindings for word oriented
-;; commands are overridden by the subword oriented commands:
-
-;; Key     Word oriented command      Subword oriented command
-;; ============================================================
-;; M-f     `forward-word'             `subword-forward'
-;; M-b     `backward-word'            `subword-backward'
-;; M-@     `mark-word'                `subword-mark'
-;; M-d     `kill-word'                `subword-kill'
-;; M-DEL   `backward-kill-word'       `subword-backward-kill'
-;; M-t     `transpose-words'          `subword-transpose'
-;; M-c     `capitalize-word'          `subword-capitalize'
-;; M-u     `upcase-word'              `subword-upcase'
-;; M-l     `downcase-word'            `subword-downcase'
-;;
-;; Note: If you have changed the key bindings for the word oriented
-;; commands in your .emacs or a similar place, the keys you've changed
-;; to are also used for the corresponding subword oriented commands.
-
 ;; To make the mode turn on automatically, put the following code in
 ;; your .emacs:
 ;;
@@ -76,22 +60,29 @@
 ;; the old `c-forward-into-nomenclature' originally contributed by
 ;; Terry_Glanfield dot Southern at rxuk dot xerox dot com.
 
-;; TODO: ispell-word.
-
 ;;; Code:
 
 (defvar subword-mode-map
-  (let ((map (make-sparse-keymap)))
-    (dolist (cmd '(forward-word backward-word mark-word kill-word
-                               backward-kill-word transpose-words
-                                capitalize-word upcase-word downcase-word))
-      (let ((othercmd (let ((name (symbol-name cmd)))
-                        (string-match "\\([[:alpha:]-]+\\)-word[s]?" name)
-                        (intern (concat "subword-" (match-string 1 name))))))
-        (define-key map (vector 'remap cmd) othercmd)))
-    map)
+  ;; Leave an empty keymap present so user customization that modify
+  ;; it keep working.
+  (make-sparse-keymap)
   "Keymap used in `subword-mode' minor mode.")
 
+(defconst subword-find-word-boundary-function-table
+  (let ((tab (make-char-table nil)))
+    (set-char-table-range tab t #'subword-find-word-boundary)
+    tab)
+  "Assigned to `find-word-boundary-function-table' in `subword-mode'.")
+
+(defconst subword-empty-char-table
+  (make-char-table nil)
+  "Assigned to `find-word-boundary-function-table' while we're searching
+subwords in order to avoid unwanted reentrancy.")
+
+;;;###autoload
+(define-obsolete-function-alias
+  'capitalized-words-mode 'subword-mode "24.1")
+
 ;;;###autoload
 (define-minor-mode subword-mode
   "Toggle subword movement and editing (Subword mode).
@@ -99,8 +90,8 @@ With a prefix argument ARG, enable Subword mode if ARG is
 positive, and disable it otherwise.  If called from Lisp, enable
 the mode if ARG is omitted or nil.
 
-Subword mode is a buffer-local minor mode.  Enabling it remaps
-word-based editing commands to subword-based commands that handle
+Subword mode is a buffer-local minor mode.  Enabling it changes
+the definition of a word so that word-based commands stop inside
 symbols with mixed uppercase and lowercase letters,
 e.g. \"GtkWidget\", \"EmacsFrameClass\", \"NSGraphicsContext\".
 
@@ -114,14 +105,19 @@ called a `subword'.  Here are some examples:
   EmacsFrameClass    =>  \"Emacs\", \"Frame\" and \"Class\"
   NSGraphicsContext  =>  \"NS\", \"Graphics\" and \"Context\"
 
-The subword oriented commands activated in this minor mode recognize
-subwords in a nomenclature to move between subwords and to edit them
-as words.
+When this mode is enabled, word-oriented commands recognize
+subwords in a nomenclature to move between subwords and treat
+them as words.
 
 \\{subword-mode-map}"
     nil
     nil
-    subword-mode-map)
+    subword-mode-map
+
+    (set (make-local-variable 'find-word-boundary-function-table)
+         (if subword-mode
+             subword-find-word-boundary-function-table
+           subword-empty-char-table)))
 
 (define-obsolete-function-alias 'c-subword-mode 'subword-mode "23.2")
 
@@ -261,7 +257,6 @@ Optional argument ARG is the same as for `capitalize-word'."
         (match-end 0))))
     (forward-word 1)))
 
-
 (defun subword-backward-internal ()
   (if (save-excursion
        (let ((case-fold-search nil))
@@ -280,6 +275,19 @@ Optional argument ARG is the same as for 
`capitalize-word'."
         (1+ (match-beginning 0)))))
     (backward-word 1)))
 
+(defun subword-find-word-boundary (pos limit)
+  (let ((find-word-boundary-function-table subword-empty-char-table))
+    (save-match-data
+      (save-excursion
+        (save-restriction
+          (if (< pos limit)
+              (progn
+                (narrow-to-region (point-min) limit)
+                (subword-forward-internal))
+            (narrow-to-region limit (point-max))
+            (subword-backward-internal))
+          (point))))))
+
 
 (provide 'subword)
 
diff --git a/test/automated/subword.el b/test/automated/subword.el
new file mode 100644
index 0000000..9e769cf
--- /dev/null
+++ b/test/automated/subword.el
@@ -0,0 +1,58 @@
+;;; vc-bzr.el --- tests for progmodes/subword.el
+
+;; Copyright (C) 2011  Free Software Foundation, Inc.
+
+;; Author: Daniel Colascione <address@hidden>
+
+;; This file is part of GNU Emacs.
+
+;; GNU Emacs is free software: you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; GNU Emacs is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;;; Code:
+
+(require 'ert)
+(require 'subword)
+
+(ert-deftest subword-test-forward ()
+  "Test that motion in subword-mode stops at the right places."
+
+  (let* ((line "fooBarBAZ quXD g_TESTThingAbc word BLAH test")
+         (fwrd "*  *  *  *  * * *    *    *  *    *    *    *")
+         (bkwd "*  *  *   * *  * *   *    *   *    *    *   *"))
+
+    (with-temp-buffer
+      (subword-mode 1)
+      (insert line)
+
+      ;; Test forward motion.
+      
+      (goto-char (point-min))
+      (let ((stops (make-string (length fwrd) ?\ )))
+        (while (progn
+                 (aset stops (1- (point)) ?\*)
+                 (not (eobp)))          
+          (forward-word))
+        (should (equal stops fwrd)))
+
+      ;; Test backward motion.
+
+      (goto-char (point-max))
+      (let ((stops (make-string (length bkwd) ?\ )))
+        (while (progn
+                 (aset stops (1- (point)) ?\*)
+                 (not (bobp)))          
+          (backward-word))
+        (should (equal stops bkwd))))))
-- 
1.7.2.5