--- gforth/except.fs	2007/02/18 18:30:51	1.17
+++ gforth/except.fs	2010/08/31 20:10:59	1.22
@@ -1,12 +1,12 @@
 \ catch, throw, etc.
 
-\ Copyright (C) 1999,2000,2003,2006 Free Software Foundation, Inc.
+\ Copyright (C) 1999,2000,2003,2006,2007 Free Software Foundation, Inc.
 
 \ This file is part of Gforth.
 
 \ Gforth 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 2
+\ as published by the Free Software Foundation, either version 3
 \ of the License, or (at your option) any later version.
 
 \ This program is distributed in the hope that it will be useful,
@@ -15,8 +15,7 @@
 \ GNU General Public License for more details.
 
 \ You should have received a copy of the GNU General Public License
-\ along with this program; if not, write to the Free Software
-\ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
+\ along with this program. If not, see http://www.gnu.org/licenses/.
 
 \ !! use a separate exception stack?           anton
 
@@ -76,6 +75,25 @@ Variable first-throw
     \G backtrace.
     first-throw on ;
 
+: (try0) ( -- aoldhandler )
+    first-throw on
+    handler @ ;
+
+[undefined] (try1) [if]
+: (try1) ( aoldhandler arecovery -- anewhandler )
+    r>
+    swap >r \ recovery address
+    sp@ cell+ >r
+    fp@ >r
+    lp@ >r
+    swap >r \ old handler
+    rp@ swap \ new handler
+    >r ;
+[endif]
+
+: (try2)
+    handler ! ;
+
 : (try) ( ahandler -- )
     first-throw on
     r>
@@ -87,10 +105,17 @@ Variable first-throw
     rp@ handler !
     >r ;
 
-: try ( compilation  -- orig ; run-time  -- ) \ gforth
-    \ !! does not work correctly for gforth-native
+\ : try ( compilation  -- orig ; run-time  -- R:sys1 ) \ gforth
+\     \G Start an exception-catching region.
+\     POSTPONE ahead here >r >mark 1 cs-roll POSTPONE then
+\     r> POSTPONE literal POSTPONE (try) ; immediate compile-only
+
+: try ( compilation  -- orig ; run-time  -- R:sys1 ) \ gforth
+    \G Start an exception-catching region.
     POSTPONE ahead here >r >mark 1 cs-roll POSTPONE then
-    r> POSTPONE literal POSTPONE (try) ; immediate compile-only
+    POSTPONE (try0) r> POSTPONE literal POSTPONE (try1) POSTPONE (try2)
+; immediate compile-only
+
 
 : (endtry) ( -- )
     \ normal end of try block: restore handler, forget rest
@@ -108,18 +133,33 @@ Variable first-throw
 ;
 
 : iferror ( compilation  orig1 -- orig2 ; run-time  -- ) \ gforth
+    \G Starts the exception handling code (executed if there is an
+    \G exception between @code{try} and @code{endtry}).  This part has
+    \G to be finished with @code{then}.
     \ !! check using a special tag
     POSTPONE else handler-intro,
 ; immediate compile-only
 
 : restore ( compilation  orig1 -- ; run-time  -- ) \ gforth
+    \G Starts restoring code, that is executed if there is an
+    \G exception, and if there is no exception.
     POSTPONE iferror POSTPONE then
 ; immediate compile-only
 
-: endtry ( compilation  -- ; run-time  -- ) \ gforth
+: endtry ( compilation  -- ; run-time  R:sys1 -- ) \ gforth
+    \G End an exception-catching region.
     POSTPONE (endtry)
 ; immediate compile-only
 
+: endtry-iferror ( compilation  orig1 -- orig2 ; run-time  R:sys1 -- ) \ gforth
+    \G End an exception-catching region while starting
+    \G exception-handling code outside that region (executed if there
+    \G is an exception between @code{try} and @code{endtry-iferror}).
+    \G This part has to be finished with @code{then} (or
+    \G @code{else}...@code{then}).
+    POSTPONE (endtry) POSTPONE iferror POSTPONE (endtry)
+; immediate compile-only
+
 :noname ( x1 .. xn xt -- y1 .. ym 0 / z1 .. zn error ) \ exception
     try
 	execute 0
@@ -140,11 +180,10 @@ is catch
 	    2 (bye)
 \	    quit
 	THEN
-	dup rp!
-	rdrop
-	r> lp!
-	r> fp!
-	r> -rot 2>r sp! drop 2r>
-	r@ swap rp! perform
+        dup rp! ( ... ball frame )
+        cell+ dup @ lp!
+        cell+ dup @ fp!
+        cell+ dup @ ( ... ball addr sp ) -rot 2>r sp! drop 2r>
+        cell+ @ perform
     THEN ;
 is throw