From dec345dc3b77affb98207d7387093dbdee39c08b Mon Sep 17 00:00:00 2001
From: H.G.Muller <hgm@hgm-xboard.(none)>
Date: Mon, 3 Mar 2014 14:37:46 +0100
Subject: [PATCH] Implement analysis mode

The XBoard commands 'analyze' and 'exit' are recognized, to set and
clear a new analysis flag (and set force mode). While the flag is set
the input loop will order a background search on the current position
while waiting for input. (Note that the 'exit' command outside XBoard
mode is synonymous for 'quit'!)
BEWARE: automatic updates interrupt the analysis.
---
 gnushogi/commondsp.c |   19 ++++++++++++++++++-
 gnushogi/gnushogi.h  |    1 +
 2 files changed, 19 insertions(+), 1 deletions(-)

diff --git a/gnushogi/commondsp.c b/gnushogi/commondsp.c
index 4718fd9..9556f63 100644
--- a/gnushogi/commondsp.c
+++ b/gnushogi/commondsp.c
@@ -1575,6 +1575,10 @@ InputCommand(char *command)
     {
         player = opponent;
 
+        if (flag.analyze) {
+            SelectMove(opponent, BACKGROUND_MODE);
+        }
+
 #ifdef QUIETBACKGROUND
         if (!have_shown_prompt)
         {
@@ -1636,7 +1640,7 @@ InputCommand(char *command)
             /* noop */ ;
         }
         else if ((strcmp(s, "quit") == 0) ||
-                 (strcmp(s, "exit") == 0))
+                 (strcmp(s, "exit") == 0) && !xboard)
         {
             flag.quit = true;
         }
@@ -1665,6 +1669,19 @@ InputCommand(char *command)
                 );
             printf("debug=1 setboard=0 sigint=0 done=1\n");
         }
+        else if (strcmp(s, ".") == 0)
+        {   // ignore for now
+        }
+        else if (strcmp(s, "exit") == 0)
+        {
+            flag.analyze = false;
+            flag.force = true;
+        }
+        else if (strcmp(s, "analyze") == 0)
+        {
+            flag.analyze = true;
+            flag.force = true;
+        }
         else if ((strcmp(s, "set") == 0) ||
                  (strcmp(s, "edit") == 0))
         {
diff --git a/gnushogi/gnushogi.h b/gnushogi/gnushogi.h
index 4e2b23e..0e3e0de 100644
--- a/gnushogi/gnushogi.h
+++ b/gnushogi/gnushogi.h
@@ -642,6 +642,7 @@ struct flags
     short bothsides;         /* computer plays both sides */
     short hash;              /* enable/disable transposition table */
     short force;             /* enter moves */
+    short analyze;           /* search during move entry */
     short easy;              /* disable thinking on opponents time */
     short beep;              /* enable/disable beep */
     short timeout;           /* time to make a move */
-- 
1.7.0.4