--- a/KeyedCollection.st	Wed Mar 15 20:45:50 2017 +0100
+++ b/KeyedCollection.st	Thu Mar 16 13:36:12 2017 +0100
@@ -57,6 +57,67 @@
 "
 ! !
 
+!KeyedCollection class methodsFor:'instance creation'!
+
+withAssociations:aCollectionOfAssociations
+    "return a new instance where associations are taken from the argument"
+
+    |newDict sz "{ Class: SmallInteger }"|
+
+    sz := aCollectionOfAssociations size.
+    newDict := self new:sz.
+    aCollectionOfAssociations do:[:assoc |
+        newDict at:assoc key put:assoc value
+    ].
+    ^ newDict
+
+    "
+     KeyValueList withAssociations:{ #'one'->1 .
+                                   #'two'->2 .
+                                   #'three'->3 .
+                                   #'four'->4 }
+    "
+
+    "Created: / 16-03-2017 / 12:15:38 / stefan"
+!
+
+withKeys:keyArray andValues:valueArray
+    "return a new instance where keys and values are taken from
+     the argumentArrays."
+
+    |newColl sz "{ Class: SmallInteger }"|
+
+    sz := keyArray size.
+    newColl := self new:sz.
+    1 to:sz do:[:index |
+        newColl at:(keyArray at:index) put:(valueArray at:index).
+    ].
+    ^ newColl
+
+    "Created: / 16-03-2017 / 11:06:51 / stefan"
+    "Modified (format): / 16-03-2017 / 12:12:09 / stefan"
+!
+
+withKeysAndValues:anArray
+    "return a new instance where keys and values are taken from alternating
+     elements of anArray"
+
+    |newDict sz "{ Class: SmallInteger }"|
+
+    sz := anArray size.
+    newDict := self new:(sz // 2).
+    1 to:sz by:2 do:[:i |
+        newDict at:(anArray at:i) put:(anArray at:i+1)
+    ].
+    ^ newDict
+
+    "
+     KeyValueList withKeysAndValues:#('one' 1 'two' 2 'three' 3 'four' 4)
+    "
+
+    "Created: / 16-03-2017 / 12:13:27 / stefan"
+! !
+
 !KeyedCollection class methodsFor:'queries'!
 
 isAbstract
@@ -69,6 +130,14 @@
 
 !KeyedCollection methodsFor:'accessing'!
 
+associationAt:key 
+    "return an association consisting of aKey and the element indexed 
+     by aKey - 
+     report an error, if no element is stored under aKey."
+
+    ^ Association key:key value:(self at:key)
+!
+
 at:key
     "return the value stored under akey.
      Raise an error if not found"