--- a/Collection.st	Sat Dec 11 01:42:02 1993 +0100
+++ b/Collection.st	Sat Dec 11 01:46:55 1993 +0100
@@ -24,7 +24,7 @@
 
 Abstract superclass for all collections
 
-$Header: /cvs/stx/stx/libbasic/Collection.st,v 1.5 1993-11-08 02:29:51 claus Exp $
+$Header: /cvs/stx/stx/libbasic/Collection.st,v 1.6 1993-12-11 00:45:11 claus Exp $
 '!
 
 !Collection class methodsFor:'initialization'!
@@ -150,6 +150,12 @@
     ^ self add:anObject
 !
 
+addFirst:anObject
+    "add the argument, anObject to the receiver"
+
+    ^ self subclassResponsibility
+!
+
 addAll:aCollection
     "add all elements of the argument, aCollection to the receiver"
 
@@ -159,6 +165,28 @@
     ^ aCollection
 !
 
+addAllLast:aCollection
+    "add all elements of the argument, aCollection to the receiver"
+
+    ^ self addAll:aCollection
+!
+
+addAllFirst:aCollection
+    "insert all elements of the argument, aCollection at the beginning
+     of the receiver"
+
+    aCollection reverseDo:[:element | 
+        self addFirst: element 
+    ].
+    ^ aCollection
+
+    "
+     |c|
+     c := #(4 3 2 1) asOrderedCollection.
+     c addAllFirst:#(9 8 7 6 5)
+    "
+!
+
 remove:anObject ifAbsent:exceptionBlock
     "remove the argument, anObject from the receiver - if it was not
      in the collection returns the the value of the exceptionBlock"
@@ -337,6 +365,14 @@
         (aBlock value:each) ifTrue:[newCollection add:each].
     ].
     ^ newCollection
+!
+
+addAllTo:aCollection
+    "add all elements of the receiver, to aCollection.
+     Return aCollection."
+
+    self do:[:each | aCollection add:each].
+    ^ aCollection
 ! !
 
 !Collection methodsFor:'converting'!
@@ -405,31 +441,25 @@
 asBag
     "return a new Bag with the receiver collections elements"
 
-    |aBag|
-
-    aBag := Bag new.
-    self do:[:each | aBag add:each].
-    ^ aBag
+    ^ self addAllTo:(Bag new)
 !
 
 asOrderedCollection
     "return a new OrderedCollection with the receiver collections elements"
 
-    |anOrderedCollection|
-
-    anOrderedCollection := OrderedCollection new:self size.
-    self do:[:each | anOrderedCollection addLast:each].
-    ^ anOrderedCollection
+    ^ self addAllTo:(OrderedCollection new:self size)
 !
 
 asSet
     "return a new Set with the receiver collections elements"
 
-    |aSet|
+    ^ self addAllTo:(Set new:self size)
+!
 
-    aSet := Set new: self size.
-    self do:[:each | aSet add:each].
-    ^ aSet
+asIdentitySet
+    "return a new IdentitySet with the receiver collections elements"
+
+    ^ self addAllTo:(IdentitySet new:self size)
 !
 
 asSortedCollection
@@ -471,11 +501,9 @@
     ^ 5000
 !
 
-printString
-    "return the printString of a big collection can take a long time
-     due to long temporary strings - I use a buffer here collecting some
-     elements to reduce the GC overhead ...
-    "
+printOrDisplayStringUsing:aSelector
+    "common code for printString and displayString; they only differ in
+     the print-message sent to the elements"
 
     |thisString buffer count string noneYet total|
 
@@ -485,7 +513,7 @@
     count := 0.
     total := 0.
     self do: [:element |
-        thisString := element printString.
+        thisString := element perform:aSelector.
         noneYet ifTrue:[
             noneYet := false.
             buffer := buffer , thisString
@@ -508,41 +536,16 @@
     ^string
 !
 
-displayString
-    "return the printString of a big collection can take a long time
-     due to long temporary strings - I use a buffer here collecting some
-     elements to reduce the GC overhead ...
-    "
-
-    |thisString buffer count string noneYet total|
+printString
+    "return a printed representation of the receiver"
 
-    string := (self class name) , '('.
-    noneYet := true.
-    buffer := ''.
-    count := 0.
-    total := 0.
-    self do: [:element |
-        thisString := element displayString.
-        noneYet ifTrue:[
-            noneYet := false.
-            buffer := buffer , thisString
-        ] ifFalse:[
-            buffer := buffer , (' ' , thisString)
-        ].
-        count := count + 1.
-        (count == 20) ifTrue:[
-            string := string , buffer.
-            buffer := ''.
-            count := 0
-        ].
-        total := total + 1.
-        (total > 5000) ifTrue:[
-            string := string , buffer , '... )'.
-            ^string
-        ]
-    ].
-    string := string , buffer , ')'.
-    ^string
+    ^ self printOrDisplayStringUsing:#printString 
+!
+
+displayString
+    "return a printed representation of the receiver for display in inspectors etc."
+
+    ^ self printOrDisplayStringUsing:#displayString 
 !
 
 printOn:aStream