--- gforth/assert.fs	2010/12/31 18:09:02	1.17
+++ gforth/assert.fs	2012/12/31 15:25:17	1.19
@@ -1,6 +1,6 @@
 \ assertions
 
-\ Copyright (C) 1995,1996,1997,1999,2002,2003,2007,2010 Free Software Foundation, Inc.
+\ Copyright (C) 1995,1996,1997,1999,2002,2003,2007,2010,2012 Free Software Foundation, Inc.
 
 \ This file is part of Gforth.
 
@@ -23,13 +23,33 @@ variable assert-level ( -- a-addr ) \ gf
 \G All assertions above this level are turned off.
 1 assert-level !
 
+: (end-assert) ( flag nfile nline -- ) \ gforth-internal
+    rot if
+	2drop
+    else
+	.sourcepos ." : failed assertion"
+	true abort" assertion failed" \ !! or use a new throw code?
+    then ;
+
+: assert) ( -- )
+    compile-sourcepos POSTPONE (end-assert) ;
+
+6 Constant assert-canary
+
 : assertn ( n -- ) \ gforth assert-n
     \ this is internal (it is not immediate)
     assert-level @ >
     if
 	POSTPONE (
+    else
+	['] assert) assert-canary
     then ;
 
+: )  ( -- ) \ gforth	close-paren
+    \G End an assertion. Generic end, can be used for other similar purposes
+    assert-canary <> abort" unmatched assertion"
+    execute ; immediate
+
 : assert0( ( -- ) \ gforth assert-zero
     \G Important assertions that should always be turned on.
     0 assertn ; immediate compile-only
@@ -47,14 +67,3 @@ variable assert-level ( -- a-addr ) \ gf
     \G Equivalent to @code{assert1(}
     POSTPONE assert1( ; immediate compile-only
 
-: (end-assert) ( flag nfile nline -- ) \ gforth-internal
-    rot if
-	2drop
-    else
-	.sourcepos ." : failed assertion"
-	true abort" assertion failed" \ !! or use a new throw code?
-    then ;
-
-: ) ( -- ) \ gforth	close-paren
-\G End an assertion.
-    compile-sourcepos POSTPONE (end-assert) ; immediate