From 4a3be107ae0c78e1b0f95cb90eda63af18ff4d36 Mon Sep 17 00:00:00 2001
From: "Jose A. Ortega Ruiz" <jao@gnu.org>
Date: Sun, 21 Dec 2008 16:04:39 +0100
Subject: [PATCH 01/10] FUEL: Better handling of popup windows (q goes back to
 original).

---
 misc/fuel/fuel-debug.el | 15 ++++-------
 misc/fuel/fuel-help.el  | 14 +++++-----
 misc/fuel/fuel-popup.el | 59 +++++++++++++++++++++++++++++++++++++++++
 misc/fuel/fuel-xref.el  | 23 +++++++---------
 4 files changed, 80 insertions(+), 31 deletions(-)
 create mode 100644 misc/fuel/fuel-popup.el

diff --git a/misc/fuel/fuel-debug.el b/misc/fuel/fuel-debug.el
index 46c1f74f0f..91811f62c2 100644
--- a/misc/fuel/fuel-debug.el
+++ b/misc/fuel/fuel-debug.el
@@ -14,9 +14,10 @@
 
 ;;; Code:
 
-(require 'fuel-base)
 (require 'fuel-eval)
+(require 'fuel-popup)
 (require 'fuel-font-lock)
+(require 'fuel-base)
 
 
 ;;; Customization:
@@ -82,7 +83,8 @@
 
 ;;; Debug buffer:
 
-(defvar fuel-debug--buffer nil)
+(fuel-popup--define fuel-debug--buffer
+  "*fuel debug*" 'fuel-debug-mode)
 
 (make-variable-buffer-local
  (defvar fuel-debug--last-ret nil))
@@ -90,13 +92,6 @@
 (make-variable-buffer-local
  (defvar fuel-debug--file nil))
 
-(defun fuel-debug--buffer ()
-  (or (and (buffer-live-p fuel-debug--buffer) fuel-debug--buffer)
-      (with-current-buffer
-          (setq fuel-debug--buffer (get-buffer-create "*fuel dbg*"))
-        (fuel-debug-mode)
-        (current-buffer))))
-
 (defun fuel-debug--display-retort (ret &optional success-msg no-pop file)
   (let ((err (fuel-eval--retort-error ret))
         (inhibit-read-only t))
@@ -120,7 +115,7 @@
       (setq fuel-debug--file file)
       (goto-char (point-max))
       (font-lock-fontify-buffer)
-      (when (and err (not no-pop)) (pop-to-buffer fuel-debug--buffer))
+      (when (and err (not no-pop)) (fuel-popup--display))
       (not err))))
 
 (defun fuel-debug--display-output (ret)
diff --git a/misc/fuel/fuel-help.el b/misc/fuel/fuel-help.el
index 6f232754bb..ac57954360 100644
--- a/misc/fuel/fuel-help.el
+++ b/misc/fuel/fuel-help.el
@@ -18,6 +18,7 @@
 (require 'fuel-autodoc)
 (require 'fuel-completion)
 (require 'fuel-font-lock)
+(require 'fuel-popup)
 (require 'fuel-base)
 
 
@@ -81,10 +82,9 @@
 
 ;;; Fuel help buffer and internals:
 
-(defun fuel-help--help-buffer ()
-  (with-current-buffer (get-buffer-create "*fuel help*")
-    (fuel-help-mode)
-    (current-buffer)))
+(fuel-popup--define fuel-help--buffer
+  "*fuel help*" 'fuel-help-mode)
+
 
 (defvar fuel-help--prompt-history nil)
 
@@ -111,7 +111,7 @@
       (fuel-help--insert-contents def out))))
 
 (defun fuel-help--insert-contents (def str &optional nopush)
-  (let ((hb (fuel-help--help-buffer))
+  (let ((hb (fuel-help--buffer))
         (inhibit-read-only t)
         (font-lock-verbose nil))
     (set-buffer hb)
@@ -124,7 +124,7 @@
         (kill-region (point-min) (point))
         (fuel-help--history-push (cons def (buffer-string)))))
     (set-buffer-modified-p nil)
-    (pop-to-buffer hb)
+    (fuel-popup--display)
     (goto-char (point-min))
     (message "%s" def)))
 
@@ -211,7 +211,6 @@ buffer."
   (let ((map (make-sparse-keymap)))
     (suppress-keymap map)
     (define-key map "\C-m" 'fuel-help)
-    (define-key map "q" 'bury-buffer)
     (define-key map "b" 'fuel-help-previous)
     (define-key map "f" 'fuel-help-next)
     (define-key map "l" 'fuel-help-previous)
@@ -245,6 +244,7 @@ buffer."
   (fuel-autodoc-mode)
 
   (run-mode-hooks 'fuel-help-mode-hook)
+
   (setq buffer-read-only t))
 
 
diff --git a/misc/fuel/fuel-popup.el b/misc/fuel/fuel-popup.el
new file mode 100644
index 0000000000..8cccc44836
--- /dev/null
+++ b/misc/fuel/fuel-popup.el
@@ -0,0 +1,59 @@
+;;; fuel-popup.el -- popup windows
+
+;; Copyright (C) 2008 Jose Antonio Ortega Ruiz
+;; See http://factorcode.org/license.txt for BSD license.
+
+;; Author: Jose Antonio Ortega Ruiz <jao@gnu.org>
+;; Keywords: languages, fuel, factor
+;; Start date: Sun Dec 21, 2008 14:37
+
+;;; Comentary:
+
+;; A minor mode to pop up windows and restore configurations
+;; afterwards.
+
+;;; Code:
+
+(make-variable-buffer-local
+ (defvar fuel-popup--created-window nil))
+
+(make-variable-buffer-local
+ (defvar fuel-popup--selected-window nil))
+
+(defun fuel-popup--display ()
+  (let ((selected-window (selected-window))
+        (buffer (current-buffer)))
+    (unless (eq selected-window (get-buffer-window buffer))
+      (let ((windows))
+        (walk-windows (lambda (w) (push w windows)) nil t)
+        (prog1 (pop-to-buffer buffer)
+          (set (make-local-variable 'fuel-popup--created-window)
+               (unless (memq (selected-window) windows) (selected-window)))
+          (set (make-local-variable 'fuel-popup--selected-window)
+               selected-window))))))
+
+(defun fuel-popup--quit ()
+  (interactive)
+  (let ((selected fuel-popup--selected-window)
+        (created fuel-popup--created-window))
+    (bury-buffer)
+    (when (eq created (selected-window)) (delete-window created))
+    (when (window-live-p selected) (select-window selected))))
+
+(define-minor-mode fuel-popup-mode
+  "Mode for displaying read only stuff"
+  nil nil
+  '(("q" . fuel-popup--quit)))
+
+(defmacro fuel-popup--define (fun name mode)
+  `(defun ,fun ()
+     (or (get-buffer ,name)
+         (with-current-buffer (get-buffer-create ,name)
+           (funcall ,mode)
+           (fuel-popup-mode)
+           (current-buffer)))))
+
+(put 'fuel-popup--define 'lisp-indent-function 1)
+
+(provide 'fuel-popup)
+;;; fuel-popup.el ends here
diff --git a/misc/fuel/fuel-xref.el b/misc/fuel/fuel-xref.el
index 3f02013290..8027aa4e62 100644
--- a/misc/fuel/fuel-xref.el
+++ b/misc/fuel/fuel-xref.el
@@ -45,20 +45,14 @@
 
 ;;; The xref buffer:
 
-(defvar fuel-xref--buffer-name "*fuel xref*")
-
-(defun fuel-xref--get-buffer ()
-  (let ((buffer (get-buffer fuel-xref--buffer-name)))
-    (or (and (buffer-live-p buffer) buffer)
-        (prog1
-            (set-buffer (get-buffer-create fuel-xref--buffer-name))
-          (fuel-xref-mode)))))
+(fuel-popup--define fuel-xref--buffer
+  "*fuel xref*" 'fuel-xref-mode)
 
 (defvar fuel-xref--help-string "(Press RET or click to follow crossrefs)")
 
 (defun fuel-xref--fill-buffer (title refs)
   (let ((inhibit-read-only t))
-    (with-current-buffer (fuel-xref--get-buffer)
+    (with-current-buffer (fuel-xref--buffer)
       (erase-buffer)
       (insert title "\n\n")
       (dolist (ref refs)
@@ -74,7 +68,8 @@
           (newline)))
       (when refs
         (insert "\n\n" fuel-xref--help-string "\n"))
-      (goto-char (point-min)))))
+      (goto-char (point-min))
+      (current-buffer))))
 
 (defun fuel-xref--show-callers (word)
   (let* ((cmd `(:fuel* (((:quote ,word) fuel-callers-xref))))
@@ -82,8 +77,8 @@
          (title (format (if res "Callers of '%s':"
                           "No callers found for '%s'")
                         word)))
-    (fuel-xref--fill-buffer title res)
-    (pop-to-buffer (fuel-xref--get-buffer))))
+    (set-buffer (fuel-xref--fill-buffer title res))
+    (fuel-popup--display)))
 
 (defun fuel-xref--show-callees (word)
   (let* ((cmd `(:fuel* (((:quote ,word) fuel-callees-xref))))
@@ -91,8 +86,8 @@
          (title (format (if res "Words called by '%s':"
                           "No callees found for '%s'")
                         word)))
-    (fuel-xref--fill-buffer title res)
-    (pop-to-buffer (fuel-xref--get-buffer))))
+    (set-buffer (fuel-xref--fill-buffer title res))
+    (fuel-popup--display)))
 
 
 ;;; Xref mode:

From ad728652d802f6bed1cd3e71d3ccb3d12f9333e9 Mon Sep 17 00:00:00 2001
From: "Jose A. Ortega Ruiz" <jao@gnu.org>
Date: Sun, 21 Dec 2008 16:47:16 +0100
Subject: [PATCH 02/10] FUEL: Improved internal font definition handling.

---
 misc/fuel/fuel-font-lock.el | 19 +++++++++++++++----
 misc/fuel/fuel-help.el      |  6 ++----
 misc/fuel/fuel-stack.el     |  9 ++++-----
 3 files changed, 21 insertions(+), 13 deletions(-)

diff --git a/misc/fuel/fuel-font-lock.el b/misc/fuel/fuel-font-lock.el
index 616bff2def..af3731f240 100644
--- a/misc/fuel/fuel-font-lock.el
+++ b/misc/fuel/fuel-font-lock.el
@@ -21,13 +21,24 @@
 
 ;;; Faces:
 
+(defgroup fuel-faces nil
+  "Faces used by FUEL."
+  :group 'fuel
+  :group 'faces)
+
+(defmacro fuel-font-lock--defface (face def group doc)
+  `(defface ,face (face-default-spec ,def)
+     ,(format "Face for %s." doc)
+     :group ',group
+     :group 'fuel-faces
+     :group 'faces))
+
+(put 'fuel-font-lock--defface 'lisp-indent-function 1)
+
 (defmacro fuel-font-lock--make-face (prefix def-prefix group face def doc)
   (let ((face (intern (format "%s-%s" prefix face)))
         (def (intern (format "%s-%s-face" def-prefix def))))
-    `(defface ,face (face-default-spec ,def)
-       ,(format "Face for %s." doc)
-       :group ',group
-       :group 'faces)))
+    `(fuel-font-lock--defface ,face ,def ,group ,doc)))
 
 (defmacro fuel-font-lock--define-faces (prefix def-prefix group faces)
   (let ((setup (make-symbol (format "%s--faces-setup" prefix))))
diff --git a/misc/fuel/fuel-help.el b/misc/fuel/fuel-help.el
index ac57954360..a8aaa80ee5 100644
--- a/misc/fuel/fuel-help.el
+++ b/misc/fuel/fuel-help.el
@@ -48,10 +48,8 @@
   :type 'integer
   :group 'fuel-help)
 
-(defface fuel-help-font-lock-headlines '((t (:bold t :weight bold)))
-  "Face for headlines in help buffers."
-  :group 'fuel-help
-  :group 'faces)
+(fuel-font-lock--defface fuel-help-font-lock-headlines
+  'bold fuel-hep "headlines in help buffers")
 
 
 ;;; Help browser history:
diff --git a/misc/fuel/fuel-stack.el b/misc/fuel/fuel-stack.el
index 3a19a59026..ef8b2e2d41 100644
--- a/misc/fuel/fuel-stack.el
+++ b/misc/fuel/fuel-stack.el
@@ -17,6 +17,7 @@
 (require 'fuel-autodoc)
 (require 'fuel-syntax)
 (require 'fuel-eval)
+(require 'fuel-font-lock)
 (require 'fuel-base)
 
 
@@ -26,12 +27,10 @@
   "Customization for FUEL's stack inference engine"
   :group 'fuel)
 
-(defface fuel-font-lock-stack-region (face-user-default-spec 'highlight)
-  "Face used to highlight the region whose stack effect is shown"
-  :group 'fuel-stack
-  :group 'faces)
+(fuel-font-lock--defface fuel-font-lock-stack-region
+  'highlight fuel-stack "highlighting the stack effect region")
 
-(defcustom fuel-stack-highlight-period 2
+(defcustom fuel-stack-highlight-period 2.0
   "Time, in seconds, the region is highlighted when showing its
 stack effect.
 

From 3630933b09d3a645c4c16dc920e4790a56d318c3 Mon Sep 17 00:00:00 2001
From: "Jose A. Ortega Ruiz" <jao@gnu.org>
Date: Sun, 21 Dec 2008 17:33:53 +0100
Subject: [PATCH 03/10] FUEL: Nicer xref buffers.

---
 extra/fuel/fuel.factor |  9 +++----
 misc/fuel/README       |  7 +++++-
 misc/fuel/fuel-xref.el | 56 +++++++++++++++++++++++++++---------------
 3 files changed, 45 insertions(+), 27 deletions(-)

diff --git a/extra/fuel/fuel.factor b/extra/fuel/fuel.factor
index 29fd2a43dc..30a6962aaf 100644
--- a/extra/fuel/fuel.factor
+++ b/extra/fuel/fuel.factor
@@ -166,14 +166,11 @@ M: source-file fuel-pprint path>> fuel-pprint ;
        first2 [ (normalize-path) ] dip 2array fuel-eval-set-result
     ] when* ; inline
 
-: fuel-xref-desc ( word -- str )
-    [ name>> ]
-    [ vocabulary>> [ " (" prepend ")" append ] [ "" ] if* ] bi append ; inline
-
 : fuel-format-xrefs ( seq -- seq )
     [ word? ] filter [
-        [ fuel-xref-desc ]
-        [ where [ first2 [ (normalize-path) ] dip ] [ f f ] if* ] bi 3array
+        [ name>> ]
+        [ vocabulary>> ]
+        [ where [ first2 [ (normalize-path) ] dip ] [ f f ] if* ] tri 4array
     ] map [ [ first ] dip first <=> ] sort ; inline
 
 : fuel-callers-xref ( word -- )
diff --git a/misc/fuel/README b/misc/fuel/README
index 0d2541b103..b21a14b9f2 100644
--- a/misc/fuel/README
+++ b/misc/fuel/README
@@ -96,5 +96,10 @@ C-cC-eC-r is the same as C-cC-er)).
  - SPC/S-SPC : scroll up/down
  - TAB/S-TAB : next/previous headline
  - C-cz : switch to listener
- - q: bury buffer
+ - q : bury buffer
 
+* In crossref buffers
+
+ - TAB/BACKTAB : navigate links
+ - RET/mouse click : follow link
+ - q : bury buffer
diff --git a/misc/fuel/fuel-xref.el b/misc/fuel/fuel-xref.el
index 8027aa4e62..4e276c1b22 100644
--- a/misc/fuel/fuel-xref.el
+++ b/misc/fuel/fuel-xref.el
@@ -13,6 +13,9 @@
 
 ;;; Code:
 
+(require 'fuel-eval)
+(require 'fuel-popup)
+(require 'fuel-font-lock)
 (require 'fuel-base)
 
 (require 'button)
@@ -24,13 +27,19 @@
   "FUEL's cross-referencing engine."
   :group 'fuel)
 
+(fuel-font-lock--defface fuel-font-lock-xref-link
+  'link fuel-xref "highlighting links in cross-reference buffers")
+
+(fuel-font-lock--defface fuel-font-lock-xref-vocab
+  'italic fuel-xref "vocabulary names in cross-reference buffers")
+
 
 ;;; Buttons:
 
 (define-button-type 'fuel-xref--button-type
   'action 'fuel-xref--follow-link
   'follow-link t
-  'face 'default)
+  'face 'fuel-font-lock-xref-link)
 
 (defun fuel-xref--follow-link (button)
   (let ((file (button-get button 'file))
@@ -50,43 +59,50 @@
 
 (defvar fuel-xref--help-string "(Press RET or click to follow crossrefs)")
 
-(defun fuel-xref--fill-buffer (title refs)
-  (let ((inhibit-read-only t))
+(defun fuel-xref--title (word cc count)
+  (cond ((zerop count) (format "No known words %s '%s'." cc word))
+        ((= 1 count) (format "1 word %s '%s':" cc word))
+        (t (format "%s words %s '%s':" count cc word))))
+
+(defun fuel-xref--fill-buffer (word cc refs)
+  (let ((inhibit-read-only t)
+        (count 0))
     (with-current-buffer (fuel-xref--buffer)
       (erase-buffer)
-      (insert title "\n\n")
       (dolist (ref refs)
-        (when (and (first ref) (second ref) (numberp (third ref)))
+        (when (and (stringp (first ref))
+                   (stringp (third ref))
+                   (numberp (fourth ref)))
           (insert "  ")
           (insert-text-button (first ref)
                               :type 'fuel-xref--button-type
                               'help-echo (format "File: %s (%s)"
                                                  (second ref)
                                                  (third ref))
-                              'file (second ref)
-                              'line (third ref))
+                              'file (third ref)
+                              'line (fourth ref))
+          (when (stringp (second ref))
+            (insert (format " (in %s)" (second ref))))
+          (setq count (1+ count))
           (newline)))
-      (when refs
-        (insert "\n\n" fuel-xref--help-string "\n"))
+      (goto-char (point-min))
+      (insert (fuel-xref--title word (if cc "using" "used by") count) "\n\n")
+      (when (> count 0)
+        (goto-char (point-max))
+        (insert "\n" fuel-xref--help-string "\n"))
       (goto-char (point-min))
       (current-buffer))))
 
 (defun fuel-xref--show-callers (word)
   (let* ((cmd `(:fuel* (((:quote ,word) fuel-callers-xref))))
-         (res (fuel-eval--retort-result (fuel-eval--send/wait cmd)))
-         (title (format (if res "Callers of '%s':"
-                          "No callers found for '%s'")
-                        word)))
-    (set-buffer (fuel-xref--fill-buffer title res))
+         (res (fuel-eval--retort-result (fuel-eval--send/wait cmd))))
+    (set-buffer (fuel-xref--fill-buffer word t res))
     (fuel-popup--display)))
 
 (defun fuel-xref--show-callees (word)
   (let* ((cmd `(:fuel* (((:quote ,word) fuel-callees-xref))))
-         (res (fuel-eval--retort-result (fuel-eval--send/wait cmd)))
-         (title (format (if res "Words called by '%s':"
-                          "No callees found for '%s'")
-                        word)))
-    (set-buffer (fuel-xref--fill-buffer title res))
+         (res (fuel-eval--retort-result (fuel-eval--send/wait cmd))))
+    (set-buffer (fuel-xref--fill-buffer word nil res))
     (fuel-popup--display)))
 
 
@@ -108,7 +124,7 @@
   (use-local-map fuel-xref-mode-map)
   (setq mode-name "FUEL Xref")
   (setq major-mode 'fuel-xref-mode)
-  (fuel-font-lock--font-lock-setup)
+  (font-lock-add-keywords nil '(("(in \\(.+\\))" 1 'fuel-font-lock-xref-vocab)))
   (setq buffer-read-only t))
 
 

From 3721086424288fb5c707e45fbfb401b6f4facd93 Mon Sep 17 00:00:00 2001
From: "Jose A. Ortega Ruiz" <jao@gnu.org>
Date: Sun, 21 Dec 2008 18:39:59 +0100
Subject: [PATCH 04/10] FUEL: Small improvements to xref mode.

---
 extra/fuel/fuel.factor       | 10 -----
 misc/fuel/fuel-connection.el |  2 +-
 misc/fuel/fuel-mode.el       |  6 +--
 misc/fuel/fuel-popup.el      |  3 +-
 misc/fuel/fuel-syntax.el     |  5 +++
 misc/fuel/fuel-xref.el       | 77 ++++++++++++++++++++++++------------
 6 files changed, 61 insertions(+), 42 deletions(-)

diff --git a/extra/fuel/fuel.factor b/extra/fuel/fuel.factor
index 30a6962aaf..7ce7c2b779 100644
--- a/extra/fuel/fuel.factor
+++ b/extra/fuel/fuel.factor
@@ -147,16 +147,6 @@ M: source-file fuel-pprint path>> fuel-pprint ;
         (fuel-eval)
     ] (fuel-end-eval) ;
 
-: fuel-begin-eval ( in -- )
-    (fuel-begin-eval)
-    (fuel-eval-in)
-    fuel-retort ;
-
-: fuel-eval ( lines -- )
-    (fuel-begin-eval) [ (fuel-eval) ] (fuel-end-eval) ; inline
-
-: fuel-end-eval ( -- ) [ ] (fuel-end-eval) ; inline
-
 : fuel-run-file ( path -- ) run-file ; inline
 
 ! Edit locations
diff --git a/misc/fuel/fuel-connection.el b/misc/fuel/fuel-connection.el
index 162a1edd02..d029f6a056 100644
--- a/misc/fuel/fuel-connection.el
+++ b/misc/fuel/fuel-connection.el
@@ -134,7 +134,7 @@
 
 (defconst fuel-con--prompt-regex "( .+ ) ")
 (defconst fuel-con--eot-marker "<~FUEL~>")
-(defconst fuel-con--init-stanza "USE: fuel f fuel-eval")
+(defconst fuel-con--init-stanza "USE: fuel fuel-retort")
 
 (defconst fuel-con--comint-finished-regex
   (format "^%s$" fuel-con--eot-marker))
diff --git a/misc/fuel/fuel-mode.el b/misc/fuel/fuel-mode.el
index b855cc340a..812f1e5b2b 100644
--- a/misc/fuel/fuel-mode.el
+++ b/misc/fuel/fuel-mode.el
@@ -183,8 +183,7 @@ With prefix argument, ask for word."
                 (fuel-syntax-symbol-at-point))))
     (when word
       (message "Looking up %s's callers ..." word)
-      (fuel-xref--show-callers word)
-      (message ""))))
+      (fuel-xref--show-callers word))))
 
 (defun fuel-show-callees (&optional arg)
   "Show a list of callers of word at point.
@@ -196,8 +195,7 @@ With prefix argument, ask for word."
                 (fuel-syntax-symbol-at-point))))
     (when word
       (message "Looking up %s's callees ..." word)
-      (fuel-xref--show-callees word)
-      (message ""))))
+      (fuel-xref--show-callees word))))
 
 
 ;;; Minor mode definition:
diff --git a/misc/fuel/fuel-popup.el b/misc/fuel/fuel-popup.el
index 8cccc44836..f18e77b321 100644
--- a/misc/fuel/fuel-popup.el
+++ b/misc/fuel/fuel-popup.el
@@ -20,7 +20,8 @@
 (make-variable-buffer-local
  (defvar fuel-popup--selected-window nil))
 
-(defun fuel-popup--display ()
+(defun fuel-popup--display (&optional buffer)
+  (when buffer (set-buffer buffer))
   (let ((selected-window (selected-window))
         (buffer (current-buffer)))
     (unless (eq selected-window (get-buffer-window buffer))
diff --git a/misc/fuel/fuel-syntax.el b/misc/fuel/fuel-syntax.el
index 5f7ab4341c..e8508f88cc 100644
--- a/misc/fuel/fuel-syntax.el
+++ b/misc/fuel/fuel-syntax.el
@@ -277,6 +277,11 @@
 (defsubst fuel-syntax--end-of-defun ()
   (re-search-forward fuel-syntax--end-of-def-regex nil t))
 
+(defsubst fuel-syntax--end-of-defun-pos ()
+  (save-excursion
+    (re-search-forward fuel-syntax--end-of-def-regex nil t)
+    (point)))
+
 (defconst fuel-syntax--defun-signature-regex
   (format "\\(%s\\|%s\\)"
           (format ":[^ ]* [^ ]+\\(%s\\)*" fuel-syntax--stack-effect-regex)
diff --git a/misc/fuel/fuel-xref.el b/misc/fuel/fuel-xref.el
index 4e276c1b22..f7ff1dea66 100644
--- a/misc/fuel/fuel-xref.el
+++ b/misc/fuel/fuel-xref.el
@@ -14,6 +14,7 @@
 ;;; Code:
 
 (require 'fuel-eval)
+(require 'fuel-syntax)
 (require 'fuel-popup)
 (require 'fuel-font-lock)
 (require 'fuel-base)
@@ -27,6 +28,12 @@
   "FUEL's cross-referencing engine."
   :group 'fuel)
 
+(defcustom fuel-xref-follow-link-to-word-p t
+  "Whether, when following a link to a caller, we position the
+cursor at the first ocurrence of the used word."
+  :group 'fuel-xref
+  :type 'boolean)
+
 (fuel-font-lock--defface fuel-font-lock-xref-link
   'link fuel-xref "highlighting links in cross-reference buffers")
 
@@ -48,8 +55,14 @@
       (error "No file for this ref"))
     (when (not (file-readable-p file))
       (error "File '%s' is not readable" file))
-    (find-file-other-window file)
-    (when (numberp line) (goto-line line))))
+    (let ((word fuel-xref--word))
+      (find-file-other-window file)
+      (when (numberp line) (goto-line line))
+      (when (and word fuel-xref-follow-link-to-word-p)
+        (and (search-forward word
+                             (fuel-syntax--end-of-defun-pos)
+                             t)
+             (goto-char (match-beginning 0)))))))
 
 
 ;;; The xref buffer:
@@ -57,12 +70,32 @@
 (fuel-popup--define fuel-xref--buffer
   "*fuel xref*" 'fuel-xref-mode)
 
+(make-local-variable (defvar fuel-xref--word nil))
+
 (defvar fuel-xref--help-string "(Press RET or click to follow crossrefs)")
 
 (defun fuel-xref--title (word cc count)
-  (cond ((zerop count) (format "No known words %s '%s'." cc word))
-        ((= 1 count) (format "1 word %s '%s':" cc word))
-        (t (format "%s words %s '%s':" count cc word))))
+  (let ((cc (if cc "using" "used by")))
+    (cond ((zerop count) (format "No known words %s '%s'" cc word))
+          ((= 1 count) (format "1 word %s '%s':" cc word))
+          (t (format "%s words %s '%s':" count cc word)))))
+
+(defun fuel-xref--insert-ref (ref)
+  (when (and (stringp (first ref))
+             (stringp (third ref))
+             (numberp (fourth ref)))
+    (insert "  ")
+    (insert-text-button (first ref)
+                        :type 'fuel-xref--button-type
+                        'help-echo (format "File: %s (%s)"
+                                           (third ref)
+                                           (fourth ref))
+                        'file (third ref)
+                        'line (fourth ref))
+    (when (stringp (second ref))
+      (insert (format " (in %s)" (second ref))))
+    (newline)
+    t))
 
 (defun fuel-xref--fill-buffer (word cc refs)
   (let ((inhibit-read-only t)
@@ -70,40 +103,32 @@
     (with-current-buffer (fuel-xref--buffer)
       (erase-buffer)
       (dolist (ref refs)
-        (when (and (stringp (first ref))
-                   (stringp (third ref))
-                   (numberp (fourth ref)))
-          (insert "  ")
-          (insert-text-button (first ref)
-                              :type 'fuel-xref--button-type
-                              'help-echo (format "File: %s (%s)"
-                                                 (second ref)
-                                                 (third ref))
-                              'file (third ref)
-                              'line (fourth ref))
-          (when (stringp (second ref))
-            (insert (format " (in %s)" (second ref))))
-          (setq count (1+ count))
-          (newline)))
+        (when (fuel-xref--insert-ref ref) (setq count (1+ count))))
       (goto-char (point-min))
-      (insert (fuel-xref--title word (if cc "using" "used by") count) "\n\n")
+      (insert (fuel-xref--title word cc count) "\n\n")
       (when (> count 0)
+        (setq fuel-xref--word (and cc word))
         (goto-char (point-max))
         (insert "\n" fuel-xref--help-string "\n"))
       (goto-char (point-min))
-      (current-buffer))))
+      count)))
+
+(defun fuel-xref--fill-and-display (word cc refs)
+  (let ((count (fuel-xref--fill-buffer word cc refs)))
+    (if (zerop count)
+        (error (fuel-xref--title word cc 0))
+      (message "")
+      (fuel-popup--display (fuel-xref--buffer)))))
 
 (defun fuel-xref--show-callers (word)
   (let* ((cmd `(:fuel* (((:quote ,word) fuel-callers-xref))))
          (res (fuel-eval--retort-result (fuel-eval--send/wait cmd))))
-    (set-buffer (fuel-xref--fill-buffer word t res))
-    (fuel-popup--display)))
+    (fuel-xref--fill-and-display word t res)))
 
 (defun fuel-xref--show-callees (word)
   (let* ((cmd `(:fuel* (((:quote ,word) fuel-callees-xref))))
          (res (fuel-eval--retort-result (fuel-eval--send/wait cmd))))
-    (set-buffer (fuel-xref--fill-buffer word nil res))
-    (fuel-popup--display)))
+    (fuel-xref--fill-and-display word nil res)))
 
 
 ;;; Xref mode:

From 06273fddfd00d7be3d82a11ae020e667c2b40feb Mon Sep 17 00:00:00 2001
From: "Jose A. Ortega Ruiz" <jao@gnu.org>
Date: Sun, 21 Dec 2008 19:02:17 +0100
Subject: [PATCH 05/10] FUEL: Fontify looked up word in xref buffers.

---
 misc/fuel/fuel-xref.el | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/misc/fuel/fuel-xref.el b/misc/fuel/fuel-xref.el
index f7ff1dea66..be976a5392 100644
--- a/misc/fuel/fuel-xref.el
+++ b/misc/fuel/fuel-xref.el
@@ -76,9 +76,10 @@ cursor at the first ocurrence of the used word."
 
 (defun fuel-xref--title (word cc count)
   (let ((cc (if cc "using" "used by")))
-    (cond ((zerop count) (format "No known words %s '%s'" cc word))
-          ((= 1 count) (format "1 word %s '%s':" cc word))
-          (t (format "%s words %s '%s':" count cc word)))))
+    (put-text-property 0 (length word) 'font-lock-face 'bold word)
+    (cond ((zerop count) (format "No known words %s %s" cc word))
+          ((= 1 count) (format "1 word %s %s:" cc word))
+          (t (format "%s words %s %s:" count cc word)))))
 
 (defun fuel-xref--insert-ref (ref)
   (when (and (stringp (first ref))

From 41b0bc0dd9b267053a5729453aaf33e8d83886b1 Mon Sep 17 00:00:00 2001
From: "Jose A. Ortega Ruiz" <jao@gnu.org>
Date: Sun, 21 Dec 2008 22:12:46 +0100
Subject: [PATCH 06/10] FUEL: small fixes for debug buffers.

---
 extra/fuel/fuel.factor  | 12 +++++-------
 misc/fuel/fuel-debug.el | 30 ++++++++++++++++--------------
 2 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/extra/fuel/fuel.factor b/extra/fuel/fuel.factor
index 7ce7c2b779..51f04450c3 100644
--- a/extra/fuel/fuel.factor
+++ b/extra/fuel/fuel.factor
@@ -122,8 +122,8 @@ M: source-file fuel-pprint path>> fuel-pprint ;
     fuel-forget-result
     fuel-forget-output ;
 
-: (fuel-end-eval) ( quot -- )
-    with-string-writer fuel-eval-output set-global fuel-retort
+: (fuel-end-eval) ( result -- )
+    fuel-eval-output set-global fuel-retort
     pop-fuel-status ; inline
 
 : (fuel-eval) ( lines -- )
@@ -141,11 +141,9 @@ M: source-file fuel-pprint path>> fuel-pprint ;
     [ dup "IN: " prepend 1vector (fuel-eval) in set ] when* ; inline
 
 : fuel-eval-in-context ( lines in usings -- )
-    (fuel-begin-eval) [
-        (fuel-eval-usings)
-        (fuel-eval-in)
-        (fuel-eval)
-    ] (fuel-end-eval) ;
+    (fuel-begin-eval)
+    [ (fuel-eval-usings) (fuel-eval-in) (fuel-eval) ] with-string-writer
+    (fuel-end-eval) ;
 
 : fuel-run-file ( path -- ) run-file ; inline
 
diff --git a/misc/fuel/fuel-debug.el b/misc/fuel/fuel-debug.el
index 91811f62c2..995200af6a 100644
--- a/misc/fuel/fuel-debug.el
+++ b/misc/fuel/fuel-debug.el
@@ -106,11 +106,11 @@
       (when err
         (fuel-debug--display-restarts err)
         (delete-blank-lines)
-        (newline)
-        (let ((hstr (fuel-debug--help-string err file)))
-          (if fuel-debug-show-short-help
-              (insert "-----------\n" hstr "\n")
-            (message "%s" hstr))))
+        (newline))
+      (let ((hstr (fuel-debug--help-string err file)))
+        (if fuel-debug-show-short-help
+            (insert "-----------\n" hstr "\n")
+          (message "%s" hstr)))
       (setq fuel-debug--last-ret ret)
       (setq fuel-debug--file file)
       (goto-char (point-max))
@@ -174,16 +174,16 @@
 
 (defun fuel-debug-goto-error ()
   (interactive)
-  (let* ((err (or (fuel-debug--buffer-error)
-                  (error "No errors reported")))
+  (let* ((err (fuel-debug--buffer-error))
          (file (or (fuel-debug--buffer-file)
-                   (error "No file associated with error")))
-         (l/c (fuel-eval--error-line/column err))
+                   (error "No file associated with compilation")))
+         (l/c (and err (fuel-eval--error-line/column err)))
          (line (or (car l/c) 1))
          (col (or (cdr l/c) 0)))
     (find-file-other-window file)
-    (goto-line line)
-    (forward-char col)))
+    (when line
+      (goto-line line)
+      (when col (forward-char col)))))
 
 (defun fuel-debug--read-restart-no ()
   (let ((rs (fuel-debug--buffer-restarts)))
@@ -219,9 +219,11 @@
     (unless (re-search-forward (format "^%s" info) nil t)
       (error "%s information not available" info))
     (message "Retrieving %s info ..." info)
-    (unless (fuel-debug--display-retort
-             (fuel-eval--send/wait `(:fuel ((:factor ,info))))
-             "" (fuel-debug--buffer-file))
+    (unless (fuel-debug--display-retort (fuel-eval--send/wait
+                                         `(:fuel ((:factor ,info))))
+                                        ""
+                                        nil
+                                        (fuel-debug--buffer-file))
       (error "Sorry, no %s info available" info))))
 
 

From 588dc002ce7d5abdb4189d60ad3706583ec3884f Mon Sep 17 00:00:00 2001
From: "Jose A. Ortega Ruiz" <jao@gnu.org>
Date: Mon, 22 Dec 2008 00:07:41 +0100
Subject: [PATCH 07/10] FUEL: stack mode available in listener.

---
 misc/fuel/README           |  1 +
 misc/fuel/fuel-base.el     | 14 +++++++------
 misc/fuel/fuel-listener.el | 43 +++++++++++++++++++++++++++-----------
 misc/fuel/fuel-stack.el    | 13 +++++++++---
 4 files changed, 50 insertions(+), 21 deletions(-)

diff --git a/misc/fuel/README b/misc/fuel/README
index b21a14b9f2..72cba3b482 100644
--- a/misc/fuel/README
+++ b/misc/fuel/README
@@ -78,6 +78,7 @@ C-cC-eC-r is the same as C-cC-er)).
  - TAB : complete word at point
  - M-. : edit word at point in Emacs
  - C-ca : toggle autodoc mode
+ - C-cs : toggle stack mode
  - C-cv : edit vocabulary
  - C-ch : help for word at point
  - C-ck : run file
diff --git a/misc/fuel/fuel-base.el b/misc/fuel/fuel-base.el
index 17633a22ce..6c16237d6d 100644
--- a/misc/fuel/fuel-base.el
+++ b/misc/fuel/fuel-base.el
@@ -74,12 +74,14 @@
                      len))
 
 (defsubst fuel--region-to-string (begin &optional end)
-  (mapconcat 'identity
-             (split-string (buffer-substring-no-properties begin
-                                                           (or end (point)))
-                           nil
-                           t)
-             " "))
+  (let ((end (or end (point))))
+    (if (< begin end)
+        (mapconcat 'identity
+                   (split-string (buffer-substring-no-properties begin end)
+                                 nil
+                                 t)
+                   " ")
+      "")))
 
 (defsubst empty-string-p (str) (equal str ""))
 
diff --git a/misc/fuel/fuel-listener.el b/misc/fuel/fuel-listener.el
index a12fc817a3..d8db42911e 100644
--- a/misc/fuel/fuel-listener.el
+++ b/misc/fuel/fuel-listener.el
@@ -13,8 +13,9 @@
 
 ;;; Code:
 
-(require 'fuel-eval)
+(require 'fuel-stack)
 (require 'fuel-completion)
+(require 'fuel-eval)
 (require 'fuel-connection)
 (require 'fuel-syntax)
 (require 'fuel-base)
@@ -102,16 +103,9 @@ buffer."
     (goto-char (point-max))
     (unless seen (error "No prompt found!"))))
 
-
-;;; Completion support
-
-(defsubst fuel-listener--current-vocab () nil)
-(defsubst fuel-listener--usings () nil)
-
-(defun fuel-listener--setup-completion ()
-  (setq fuel-syntax--current-vocab-function 'fuel-listener--current-vocab)
-  (setq fuel-syntax--usings-function 'fuel-listener--usings)
-  (set-syntax-table fuel-syntax--syntax-table))
+(defun fuel-listener-nuke ()
+  (interactive)
+  (fuel-con--setup-connection fuel-listener--buffer))
 
 
 ;;; Interface: starting fuel listener
@@ -128,6 +122,28 @@ buffer."
         (pop-to-buffer buf)
       (switch-to-buffer buf))))
 
+
+;;; Completion support
+
+(defsubst fuel-listener--current-vocab () nil)
+(defsubst fuel-listener--usings () nil)
+
+(defun fuel-listener--setup-completion ()
+  (setq fuel-syntax--current-vocab-function 'fuel-listener--current-vocab)
+  (setq fuel-syntax--usings-function 'fuel-listener--usings)
+  (set-syntax-table fuel-syntax--syntax-table))
+
+
+;;; Stack mode support
+
+(defun fuel-listener--stack-region ()
+  (fuel--region-to-string (if (zerop (fuel-syntax--brackets-depth))
+                              (comint-line-beginning-position)
+                            (1+ (fuel-syntax--brackets-start)))))
+
+(defun fuel-listener--setup-stack-mode ()
+  (setq fuel-stack--region-function 'fuel-listener--stack-region))
+
 
 ;;; Fuel listener mode:
 
@@ -138,12 +154,15 @@ buffer."
   (set (make-local-variable 'comint-prompt-regexp) fuel-con--prompt-regex)
   (set (make-local-variable 'comint-use-prompt-regexp) t)
   (set (make-local-variable 'comint-prompt-read-only) t)
-  (fuel-listener--setup-completion))
+  (set-syntax-table fuel-syntax--syntax-table)
+  (fuel-listener--setup-completion)
+  (fuel-listener--setup-stack-mode))
 
 (define-key fuel-listener-mode-map "\C-cz" 'run-factor)
 (define-key fuel-listener-mode-map "\C-c\C-z" 'run-factor)
 (define-key fuel-listener-mode-map "\C-ca" 'fuel-autodoc-mode)
 (define-key fuel-listener-mode-map "\C-ch" 'fuel-help)
+(define-key fuel-listener-mode-map "\C-cs" 'fuel-stack-mode)
 (define-key fuel-listener-mode-map "\M-." 'fuel-edit-word-at-point)
 (define-key fuel-listener-mode-map "\C-cv" 'fuel-edit-vocabulary)
 (define-key fuel-listener-mode-map "\C-c\C-v" 'fuel-edit-vocabulary)
diff --git a/misc/fuel/fuel-stack.el b/misc/fuel/fuel-stack.el
index ef8b2e2d41..6797b36d46 100644
--- a/misc/fuel/fuel-stack.el
+++ b/misc/fuel/fuel-stack.el
@@ -96,13 +96,20 @@ With prefix argument, use current region instead"
  (defvar fuel-stack-mode-string " S"
    "Modeline indicator for fuel-stack-mode"))
 
+(make-variable-buffer-local
+ (defvar fuel-stack--region-function
+   '(lambda ()
+      (fuel--region-to-string (1+ (fuel-syntax--beginning-of-sexp-pos))))))
+
 (defun fuel-stack--eldoc ()
   (when (looking-at-p " \\|$")
-    (let* ((r (fuel--region-to-string (1+ (fuel-syntax--beginning-of-sexp-pos))))
-           (e (fuel-stack--infer-effect/prop r)))
+    (let* ((r (funcall fuel-stack--region-function))
+           (e (and r
+                   (not (string-match "^ *$" r))
+                   (fuel-stack--infer-effect/prop r))))
       (when e
         (if fuel-stack-mode-show-sexp-p
-            (concat (fuel--shorten-str r 30) ": " e)
+            (concat (fuel--shorten-str r 30) " -> " e)
           e)))))
 
 (define-minor-mode fuel-stack-mode

From ed38c1cb6d95f856b7b2e8317123514b4d48a956 Mon Sep 17 00:00:00 2001
From: "Jose A. Ortega Ruiz" <jao@gnu.org>
Date: Mon, 22 Dec 2008 01:34:47 +0100
Subject: [PATCH 08/10] FUEL: Faces renamed for homogeneity.

---
 misc/fuel/fuel-debug.el | 18 +++++++++---------
 misc/fuel/fuel-help.el  |  5 +++--
 2 files changed, 12 insertions(+), 11 deletions(-)

diff --git a/misc/fuel/fuel-debug.el b/misc/fuel/fuel-debug.el
index 995200af6a..594f73d30f 100644
--- a/misc/fuel/fuel-debug.el
+++ b/misc/fuel/fuel-debug.el
@@ -37,7 +37,7 @@
   :type 'boolean)
 
 (fuel-font-lock--define-faces
- fuel-debug-font-lock font-lock fuel-debug
+ fuel-font-lock-debug font-lock fuel-debug
  ((error warning "highlighting errors")
   (line variable-name "line numbers in errors/warnings")
   (column variable-name "column numbers in errors/warnings")
@@ -67,14 +67,14 @@
 (defconst fuel-debug--restart-regex "^:\\([0-9]+\\) \\(.+\\)")
 
 (defconst fuel-debug--font-lock-keywords
-  `((,fuel-debug--error-file-regex . 'fuel-debug-font-lock-error)
-    (,fuel-debug--error-line-regex 1 'fuel-debug-font-lock-line)
-    (,fuel-debug--error-cont-regex 1 'fuel-debug-font-lock-column)
-    (,fuel-debug--restart-regex (1 'fuel-debug-font-lock-restart-number)
-                                (2 'fuel-debug-font-lock-restart-name))
-    (,fuel-debug--compiler-info-regex 1 'fuel-debug-font-lock-restart-number)
-    ("^\\(Restarts?\\|Loading\\) .+$" . 'fuel-debug-font-lock-info)
-    ("^Error: " . 'fuel-debug-font-lock-error)))
+  `((,fuel-debug--error-file-regex . 'fuel-font-lock-debug-error)
+    (,fuel-debug--error-line-regex 1 'fuel-font-lock-debug-line)
+    (,fuel-debug--error-cont-regex 1 'fuel-font-lock-debug-column)
+    (,fuel-debug--restart-regex (1 'fuel-font-lock-debug-restart-number)
+                                (2 'fuel-font-lock-debug-restart-name))
+    (,fuel-debug--compiler-info-regex 1 'fuel-font-lock-debug-restart-number)
+    ("^\\(Restarts?\\|Loading\\) .+$" . 'fuel-font-lock-debug-info)
+    ("^Error: " . 'fuel-font-lock-debug-error)))
 
 (defun fuel-debug--font-lock-setup ()
   (set (make-local-variable 'font-lock-defaults)
diff --git a/misc/fuel/fuel-help.el b/misc/fuel/fuel-help.el
index a8aaa80ee5..c3f3f111ec 100644
--- a/misc/fuel/fuel-help.el
+++ b/misc/fuel/fuel-help.el
@@ -48,7 +48,7 @@
   :type 'integer
   :group 'fuel-help)
 
-(fuel-font-lock--defface fuel-help-font-lock-headlines
+(fuel-font-lock--defface fuel-font-lock-help-headlines
   'bold fuel-hep "headlines in help buffers")
 
 
@@ -152,7 +152,7 @@
 
 (defconst fuel-help--font-lock-keywords
   `(,@fuel-font-lock--font-lock-keywords
-    (,fuel-help--headlines-regexp . 'fuel-help-font-lock-headlines)))
+    (,fuel-help--headlines-regexp . 'fuel-font-lock-help-headlines)))
 
 
 
@@ -219,6 +219,7 @@ buffer."
     (define-key map [(backtab)] 'fuel-help-previous-headline)
     (define-key map (kbd "SPC")  'scroll-up)
     (define-key map (kbd "S-SPC") 'scroll-down)
+    (define-key map "\M-." 'fuel-edit-word-at-point)
     (define-key map "\C-cz" 'run-factor)
     (define-key map "\C-c\C-z" 'run-factor)
     map))

From 46d3667d4b7f65a12658353dfeca9c52c1099cab Mon Sep 17 00:00:00 2001
From: "Jose A. Ortega Ruiz" <jao@gnu.org>
Date: Mon, 22 Dec 2008 01:51:41 +0100
Subject: [PATCH 09/10] FUEL: Customization docstrings homogenized.

---
 misc/fuel/fuel-autodoc.el  | 2 +-
 misc/fuel/fuel-base.el     | 2 +-
 misc/fuel/fuel-debug.el    | 6 +++---
 misc/fuel/fuel-help.el     | 2 +-
 misc/fuel/fuel-listener.el | 2 +-
 misc/fuel/fuel-stack.el    | 2 +-
 6 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/misc/fuel/fuel-autodoc.el b/misc/fuel/fuel-autodoc.el
index ddeea35abc..96c47d2c69 100644
--- a/misc/fuel/fuel-autodoc.el
+++ b/misc/fuel/fuel-autodoc.el
@@ -22,7 +22,7 @@
 ;;; Customization:
 
 (defgroup fuel-autodoc nil
-  "Options controlling FUEL's autodoc system"
+  "Options controlling FUEL's autodoc system."
   :group 'fuel)
 
 (defcustom fuel-autodoc-minibuffer-font-lock t
diff --git a/misc/fuel/fuel-base.el b/misc/fuel/fuel-base.el
index 6c16237d6d..1f946bede6 100644
--- a/misc/fuel/fuel-base.el
+++ b/misc/fuel/fuel-base.el
@@ -25,7 +25,7 @@
 
 ;;;###autoload
 (defgroup fuel nil
-  "Factor's Ultimate Emacs Library"
+  "Factor's Ultimate Emacs Library."
   :group 'language)
 
 
diff --git a/misc/fuel/fuel-debug.el b/misc/fuel/fuel-debug.el
index 594f73d30f..cac4834f3b 100644
--- a/misc/fuel/fuel-debug.el
+++ b/misc/fuel/fuel-debug.el
@@ -23,16 +23,16 @@
 ;;; Customization:
 
 (defgroup fuel-debug nil
-  "Major mode for interaction with the Factor debugger"
+  "Major mode for interaction with the Factor debugger."
   :group 'fuel)
 
 (defcustom fuel-debug-mode-hook nil
-  "Hook run after `fuel-debug-mode' activates"
+  "Hook run after `fuel-debug-mode' activates."
   :group 'fuel-debug
   :type 'hook)
 
 (defcustom fuel-debug-show-short-help t
-  "Whether to show short help on available keys in debugger"
+  "Whether to show short help on available keys in debugger."
   :group 'fuel-debug
   :type 'boolean)
 
diff --git a/misc/fuel/fuel-help.el b/misc/fuel/fuel-help.el
index c3f3f111ec..9216a9fd02 100644
--- a/misc/fuel/fuel-help.el
+++ b/misc/fuel/fuel-help.el
@@ -25,7 +25,7 @@
 ;;; Customization:
 
 (defgroup fuel-help nil
-  "Options controlling FUEL's help system"
+  "Options controlling FUEL's help system."
   :group 'fuel)
 
 (defcustom fuel-help-always-ask t
diff --git a/misc/fuel/fuel-listener.el b/misc/fuel/fuel-listener.el
index d8db42911e..d7fbfb2e74 100644
--- a/misc/fuel/fuel-listener.el
+++ b/misc/fuel/fuel-listener.el
@@ -26,7 +26,7 @@
 ;;; Customization:
 
 (defgroup fuel-listener nil
-  "Interacting with a Factor listener inside Emacs"
+  "Interacting with a Factor listener inside Emacs."
   :group 'fuel)
 
 (defcustom fuel-listener-factor-binary "~/factor/factor"
diff --git a/misc/fuel/fuel-stack.el b/misc/fuel/fuel-stack.el
index 6797b36d46..7329848aa2 100644
--- a/misc/fuel/fuel-stack.el
+++ b/misc/fuel/fuel-stack.el
@@ -24,7 +24,7 @@
 ;;; Customization
 
 (defgroup fuel-stack nil
-  "Customization for FUEL's stack inference engine"
+  "Customization for FUEL's stack inference engine."
   :group 'fuel)
 
 (fuel-font-lock--defface fuel-font-lock-stack-region

From 31d783c2bea1b61c939b89c809f55bb758238c77 Mon Sep 17 00:00:00 2001
From: "Jose A. Ortega Ruiz" <jao@gnu.org>
Date: Mon, 22 Dec 2008 03:07:45 +0100
Subject: [PATCH 10/10] FUEL: Edit word's documentation command.

---
 extra/fuel/fuel.factor   | 13 +++++++++----
 misc/fuel/README         |  3 ++-
 misc/fuel/factor-mode.el |  5 +++--
 misc/fuel/fuel-base.el   |  2 +-
 misc/fuel/fuel-mode.el   | 23 ++++++++++++++++++++---
 5 files changed, 35 insertions(+), 11 deletions(-)

diff --git a/extra/fuel/fuel.factor b/extra/fuel/fuel.factor
index 51f04450c3..93cd4f9076 100644
--- a/extra/fuel/fuel.factor
+++ b/extra/fuel/fuel.factor
@@ -149,16 +149,21 @@ M: source-file fuel-pprint path>> fuel-pprint ;
 
 ! Edit locations
 
+: fuel-normalize-loc ( seq -- path line )
+    dup length 1 > [ first2 [ (normalize-path) ] dip ] [ f ] if ; inline
+
 : fuel-get-edit-location ( defspec -- )
-    where [
-       first2 [ (normalize-path) ] dip 2array fuel-eval-set-result
-    ] when* ; inline
+    where fuel-normalize-loc 2array fuel-eval-set-result ; inline
+
+: fuel-get-doc-location ( defspec -- )
+    props>> "help-loc" swap at
+    fuel-normalize-loc 2array fuel-eval-set-result ;
 
 : fuel-format-xrefs ( seq -- seq )
     [ word? ] filter [
         [ name>> ]
         [ vocabulary>> ]
-        [ where [ first2 [ (normalize-path) ] dip ] [ f f ] if* ] tri 4array
+        [ where fuel-normalize-loc ] tri 4array
     ] map [ [ first ] dip first <=> ] sort ; inline
 
 : fuel-callers-xref ( word -- )
diff --git a/misc/fuel/README b/misc/fuel/README
index 72cba3b482..ee835f2c5c 100644
--- a/misc/fuel/README
+++ b/misc/fuel/README
@@ -58,7 +58,8 @@ C-cC-eC-r is the same as C-cC-er)).
  - M-. : edit word at point in Emacs
  - M-TAB : complete word at point
  - C-cC-ev : edit vocabulary (M-x fuel-edit-vocabulary)
- - C-cC-ew : edit word (M-x fuel-edit-word)
+ - C-cC-ew : edit word (M-x fuel-edit-word-at-point)
+ - C-cC-ed : edit word's doc (M-x fuel-edit-word-at-point)
 
  - C-cr, C-cC-er : eval region
  - C-M-r, C-cC-ee : eval region, extending it to definition boundaries
diff --git a/misc/fuel/factor-mode.el b/misc/fuel/factor-mode.el
index 7f129cd866..d354fd820a 100644
--- a/misc/fuel/factor-mode.el
+++ b/misc/fuel/factor-mode.el
@@ -24,8 +24,9 @@
 ;;; Customization:
 
 (defgroup factor-mode nil
-  "Major mode for Factor source code"
-  :group 'fuel)
+  "Major mode for Factor source code."
+  :group 'fuel
+  :group 'languages)
 
 (defcustom factor-mode-use-fuel t
   "Whether to use the full FUEL facilities in factor mode.
diff --git a/misc/fuel/fuel-base.el b/misc/fuel/fuel-base.el
index 1f946bede6..219f821daa 100644
--- a/misc/fuel/fuel-base.el
+++ b/misc/fuel/fuel-base.el
@@ -26,7 +26,7 @@
 ;;;###autoload
 (defgroup fuel nil
   "Factor's Ultimate Emacs Library."
-  :group 'language)
+  :group 'languages)
 
 
 ;;; Emacs compatibility:
diff --git a/misc/fuel/fuel-mode.el b/misc/fuel/fuel-mode.el
index 812f1e5b2b..608072c87a 100644
--- a/misc/fuel/fuel-mode.el
+++ b/misc/fuel/fuel-mode.el
@@ -135,12 +135,28 @@ buffer in case of errors."
 With prefix, asks for the word to edit."
   (interactive "P")
   (let* ((word (or (and (not arg) (fuel-syntax-symbol-at-point))
-                  (fuel-completion--read-word "Edit word: ")))
-         (cmd `(:fuel ((:quote ,word) fuel-get-edit-location))))
+                   (fuel-completion--read-word "Edit word: ")))
+         (cmd `(:fuel* ((:quote ,word) fuel-get-edit-location))))
     (condition-case nil
         (fuel--try-edit (fuel-eval--send/wait cmd))
       (error (fuel-edit-vocabulary nil word)))))
 
+(defun fuel-edit-word-doc-at-point (&optional arg)
+  "Opens a new window visiting the documentation file for the word at point.
+With prefix, asks for the word to edit."
+  (interactive "P")
+  (let* ((word (or (and (not arg) (fuel-syntax-symbol-at-point))
+                   (fuel-completion--read-word "Edit word: ")))
+         (cmd `(:fuel* ((:quote ,word) fuel-get-doc-location))))
+    (condition-case nil
+        (fuel--try-edit (fuel-eval--send/wait cmd))
+      (error (when (y-or-n-p (concat "No documentation found. "
+                                     "Do you want to open the vocab's "
+                                     "doc file? "))
+               (find-file-other-window
+                (format "%s-docs.factor"
+                        (file-name-sans-extension (buffer-file-name)))))))))
+
 (defvar fuel-mode--word-history nil)
 
 (defun fuel-edit-word (&optional arg)
@@ -152,7 +168,7 @@ offered."
                                            nil
                                            fuel-mode--word-history
                                            arg))
-         (cmd `(:fuel ((:quote ,word) fuel-get-edit-location))))
+         (cmd `(:fuel* ((:quote ,word) fuel-get-edit-location))))
     (fuel--try-edit (fuel-eval--send/wait cmd))))
 
 (defvar fuel--vocabs-prompt-history nil)
@@ -250,6 +266,7 @@ interacting with a factor listener is at your disposal.
 (define-key fuel-mode-map "\C-c\M->" 'fuel-show-callees)
 (define-key fuel-mode-map (kbd "M-TAB") 'fuel-completion--complete-symbol)
 
+(fuel-mode--key ?e ?d 'fuel-edit-word-doc-at-point)
 (fuel-mode--key ?e ?e 'fuel-eval-extended-region)
 (fuel-mode--key ?e ?l 'fuel-run-file)
 (fuel-mode--key ?e ?r 'fuel-eval-region)