# HG changeset patch
# User Claus Gittinger <cg@exept.de>
# Date 939296234 -7200
# Node ID 211a7f44946db2f6080b4a2c99e8eeef9060e20a
# Parent  3f6a8c36892596f67ddc239f12430b0a5c757f90
added #at:ifPresent:

diff -r 3f6a8c368925 -r 211a7f44946d Dictionary.st
--- a/Dictionary.st	Thu Oct 07 13:35:01 1999 +0200
+++ b/Dictionary.st	Thu Oct 07 13:37:14 1999 +0200
@@ -248,6 +248,18 @@
     "Modified: / 26.2.1998 / 19:10:09 / stefan"
 !
 
+at:aKey ifPresent:aBlock
+    "if the receiver contains an element stored under aKey,
+     retrieve it and evaluate aBlock passing the element as argument,
+     return the blocks value.
+     If not, do nothing and return nil."
+
+    |v|
+
+    v := self at:aKey ifAbsent:[^ nil].
+    ^ aBlock value:v.
+!
+
 at:aKey put:anObject
     "add the argument anObject under key, aKey to the receiver.
      Return anObject (sigh).
@@ -1431,5 +1443,5 @@
 !Dictionary class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libbasic/Dictionary.st,v 1.60 1998-11-09 21:34:15 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic/Dictionary.st,v 1.61 1999-10-07 11:37:14 cg Exp $'
 ! !