--- a/Block.st	Fri Dec 14 10:55:24 2001 +0100
+++ b/Block.st	Fri Dec 14 10:57:05 2001 +0100
@@ -1201,6 +1201,16 @@
     ^ ArgumentSignal
         raiseRequestWith:self
         errorString:'only blocks with up-to 12 arguments supported'
+!
+
+valueWithOptionalArgument:arg
+    "evaluate the receiver.
+     Optionally pass an argument (if required)."
+
+    self numArgs == 1 ifTrue:[
+        ^ self value:arg
+    ].
+    ^ self value
 ! !
 
 !Block methodsFor:'exception handling'!
@@ -1882,6 +1892,6 @@
 !Block class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libbasic/Block.st,v 1.108 2001-12-04 17:29:06 stefan Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic/Block.st,v 1.109 2001-12-14 09:57:05 cg Exp $'
 ! !
 Block initialize!