[elpa] externals/gnugo 3670b0b 228/357: [gnugo] On SGF load, leave cursor at last user board position.

[Stefan Monnier]

branch: externals/gnugo
commit 3670b0b79f34ef483059ebec4907caa2dab18e7b
Author: Thien-Thi Nguyen <ttn@gnu.org>
Commit: Thien-Thi Nguyen <ttn@gnu.org>

    [gnugo] On SGF load, leave cursor at last user board position.
    
    * packages/gnugo/gnugo.el (gnugo-move-history):
    Take optional second arg COLOR.
    (gnugo-move-history remem): New internal func.
    (gnugo-move-history pretty): New internal func.
    (gnugo-move-history next): Use ‘remem’, ‘pretty’.
    (gnugo-move-history): If RSEL is ‘bpos’, return
    the position of the last stone placed by COLOR.
    (gnugo-read-sgf-file): Set :last-user-bpos.
    (gnugo): After refresh, prefer :last-user-bpos
    to :center-position for cursor position.
---
 NEWS     |  6 ++++--
 gnugo.el | 23 ++++++++++++++++++-----
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/NEWS b/NEWS
index f552702..48b02ac 100644
--- a/NEWS
+++ b/NEWS
@@ -30,7 +30,6 @@ NB: "RCS: X..Y " means that the particular release includes
   - new command: ‘L’ (gnugo-frolic-in-the-leaves)
   - new command: ‘C-c C-a’ (gnugo-toggle-abdication)
   - new major mode: GNUGO Frolic (gnugo-frolic-mode)
-  - ‘gnugo-move-history’ returns last two moves w/ RSEL ‘two’
   - GNUGO Board mode now derived from Special mode
   - performance improvements
   - of interest to hackers (see source, BI => backward incompatible)
@@ -38,10 +37,13 @@ NB: "RCS: X..Y " means that the particular release includes
     - ‘gnugo/sgf-read-file’ renamed to ‘gnugo/sgf-create’ and enhanced
     - ‘:sgf-gametree’ internal representation inverted (BI)
     - ‘gnugo-magic-undo’ handles SPEC ‘0’
-    - dropped ‘(gnugo-move-history 'count)’ (BI)
     - new func: ‘gnugo-current-player’
     - new hook: ‘gnugo-start-game-hook’
     - ‘gnugo-board-mode-hook’ now unsuitable for prop munging (BI)
+    - changes to ‘gnugo-move-history’
+      - dropped ‘(gnugo-move-history 'count)’ (BI)
+      - returns last two moves w/ RSEL ‘two’
+      - returns position of last placed stone w/ RSEL ‘bpos’ + 2nd arg COLOR
 
 - 2.3.1 | 2014-02-27
   - portability fixes
diff --git a/gnugo.el b/gnugo.el
index e4774c4..256998b 100644
--- a/gnugo.el
+++ b/gnugo.el
@@ -708,7 +708,7 @@ when you are sure the command cannot fail."
                   (+ ?A (- (if (> ?i col) col (1+ col)) ?a))
                   (- size (- (aref cc 1) ?a))))))))
 
-(defun gnugo-move-history (&optional rsel)
+(defun gnugo-move-history (&optional rsel color)
   "Determine and return the game's move history.
 Optional arg RSEL controls side effects and return value.
 If nil, display the history in the echo area as \"(N moves)\"
@@ -719,6 +719,7 @@ RSEL may also be a symbol that selects what to return:
  car  -- the most-recent move
  cadr -- the next-to-most-recent move
  two  -- the last two moves as a list, oldest last
+ bpos -- the last stone on the board placed by COLOR
 For all other values of RSEL, do nothing and return nil."
   (interactive "P")
   (let* ((monkey (gnugo-get :monkey))
@@ -729,9 +730,11 @@ For all other values of RSEL, do nothing and return nil."
         ((as-pos-maybe (x) (if (string= "resign" x)
                                x
                              (funcall as-pos x)))
-         (next (byp) (when (setq node (pop mem)
-                                 mprop (gnugo--move-prop node))
-                       (setq move (as-pos-maybe (cdr mprop)))
+         (remem () (setq node (pop mem)
+                         mprop (gnugo--move-prop node)))
+         (pretty () (setq move (as-pos-maybe (cdr mprop))))
+         (next (byp) (when (remem)
+                       (pretty)
                        (push (if byp
                                  (format "%s%s" move (car mprop))
                                move)
@@ -747,6 +750,13 @@ For all other values of RSEL, do nothing and return nil."
         (`car        (car (nn)))
         (`cadr  (nn) (car (nn)))
         (`two (nn) (nn) acc)
+        (`bpos (loop with prop = (gnugo--prop<-color color)
+                     when (and (remem)
+                               (eq prop (car mprop))
+                               (pretty)
+                               (not (string= "resign" move))
+                               (not (gnugo--passp move)))
+                     return move))
         (_ nil)))))
 
 (define-derived-mode gnugo-frolic-mode special-mode "GNUGO Frolic"
@@ -1913,6 +1923,8 @@ If FILENAME already exists, Emacs confirms that you wish 
to overwrite it."
                                            (gnugo-move-history 'two))
                                 'two-passes)))
       (gnugo-close-game nil game-over))
+    (gnugo-put :last-user-bpos
+      (gnugo-move-history 'bpos (gnugo-get :user-color)))
     (gnugo-refresh t)
     (set-buffer-modified-p nil)
     (gnugo--who-is-who wait play samep)))
@@ -2531,7 +2543,8 @@ See `gnugo-board-mode' for a full list of commands."
                                              handicap)))))))
       (gnugo-put :waiting-start (current-time))
       (gnugo-refresh t)
-      (gnugo-goto-pos (gnugo-get :center-position))
+      (gnugo-goto-pos (or (gnugo-get :last-user-bpos)
+                          (gnugo-get :center-position)))
       ;; first move
       (gnugo-put :game-start-time (current-time))
       (let ((g (gnugo-get :gnugo-color))