--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/CacheDictionaryWithFactory.st	Fri May 09 19:15:11 2003 +0200
@@ -0,0 +1,111 @@
+"
+ COPYRIGHT (c) 2003 by eXept Software AG
+              All Rights Reserved
+
+ This software is furnished under a license and may be used
+ only in accordance with the terms of that license and with the
+ inclusion of the above copyright notice.   This software may not
+ be provided or otherwise made available to, or used by, any
+ other person.  No title to or ownership of the software is
+ hereby transferred.
+"
+
+"{ Package: 'stx:libbasic2' }"
+
+CacheDictionary subclass:#CacheDictionaryWithFactory
+	instanceVariableNames:'factoryBlock'
+	classVariableNames:''
+	poolDictionaries:''
+	category:'Collections-Unordered'
+!
+
+!CacheDictionaryWithFactory class methodsFor:'documentation'!
+
+copyright
+"
+ COPYRIGHT (c) 2003 by eXept Software AG
+              All Rights Reserved
+
+ This software is furnished under a license and may be used
+ only in accordance with the terms of that license and with the
+ inclusion of the above copyright notice.   This software may not
+ be provided or otherwise made available to, or used by, any
+ other person.  No title to or ownership of the software is
+ hereby transferred.
+"
+!
+
+documentation
+"
+    like a Dictionary, but does not grow (i.e. only keeps size items),
+    and also keeps a factoryBlock ,to automatically compute missing elements.
+
+    [author:]
+        Claus Gittinger (cg@alan)
+
+    [instance variables:]
+
+    [class variables:]
+
+    [see also:]
+
+"
+!
+
+examples
+"
+  caches reverse strings (stupid usage)
+                                                                [exBegin]
+    |c|
+
+    c := CacheDictionaryWithFactory 
+            new:100 factory:[:key | key reversed].
+
+    c at:'hello'.  
+    c at:'hello'.
+    1 to:1000 do:[:i | c at:i printString].
+    c at:'hello'.
+                                                                [exEnd]
+
+
+  Test: should halt (compute 'hello') only twice.
+                                                                [exBegin]
+    |c numHalts|
+
+    numHalts := 0.
+
+    c := CacheDictionaryWithFactory 
+            new:100 factory:[:key | key = 'hello' ifTrue:[numHalts := numHalts + 1]. key reversed].
+
+    c at:'hello'.  
+    c at:'hello'.
+    1 to:1000 do:[:i | c at:i printString].
+    c at:'hello'.
+    self assert:( numHalts == 2 ).
+                                                                [exEnd]
+"
+! !
+
+!CacheDictionaryWithFactory class methodsFor:'instance creation'!
+
+new:cacheSize factory:aBlock
+    ^ (self new:cacheSize) factory:aBlock
+! !
+
+!CacheDictionaryWithFactory methodsFor:'accessing'!
+
+at:key
+    ^ super at:key ifAbsentPut:[factoryBlock value:key]
+! !
+
+!CacheDictionaryWithFactory methodsFor:'initialization'!
+
+factory:aBlock
+    factoryBlock := aBlock
+! !
+
+!CacheDictionaryWithFactory class methodsFor:'documentation'!
+
+version
+    ^ '$Header: /cvs/stx/stx/libbasic2/CacheDictionaryWithFactory.st,v 1.1 2003-05-09 17:15:11 cg Exp $'
+! !