--- a/Bag.st	Fri Mar 01 21:42:07 1996 +0100
+++ b/Bag.st	Fri Mar 01 21:43:49 1996 +0100
@@ -11,10 +11,10 @@
 "
 
 Collection subclass:#Bag
-	 instanceVariableNames:'contents'
-	 classVariableNames:''
-	 poolDictionaries:''
-	 category:'Collections-Unordered'
+	instanceVariableNames:'contents'
+	classVariableNames:''
+	poolDictionaries:''
+	category:'Collections-Unordered'
 !
 
 !Bag class methodsFor:'documentation'!
@@ -107,47 +107,65 @@
 
 add:newObject
     "add the argument, anObject to the receiver.
-     Returns the object."
+     Returns the object.
+
+     WARNING: do not add/remove elements while iterating over the receiver.
+              Iterate over a copy to do this."
 
     |n|
 
     n := contents at:newObject ifAbsent:[0].
     contents at:newObject put:(n + 1).
     ^ newObject
+
+    "Modified: 1.3.1996 / 21:43:06 / cg"
 !
 
 add:newObject withOccurences:anInteger
     "add the argument, anObject anInteger times to the receiver.
-     Returns the object."
+     Returns the object.
+
+     WARNING: do not add/remove elements while iterating over the receiver.
+              Iterate over a copy to do this."
 
     |n|
 
     n := contents at:newObject ifAbsent:[0].
     contents at:newObject put:(n + anInteger).
     ^ newObject
+
+    "Modified: 1.3.1996 / 21:43:12 / cg"
 !
 
 remove:oldObject ifAbsent:anExceptionBlock
     "Remove oldObject from the collection.
      If it was not present, return the value of the exceptionBlock;
-     otherwise return the removed object."
+     otherwise return the removed object.
+
+     WARNING: do not add/remove elements while iterating over the receiver.
+              Iterate over a copy to do this."
 
     |count|
 
     count := contents at:oldObject ifAbsent:[0].
     (count == 0) ifTrue:[^ anExceptionBlock value].
     (count == 1) ifTrue:[
-	contents removeKey:oldObject
+        contents removeKey:oldObject
     ] ifFalse:[ 
-	contents at:oldObject put:(count - 1)
+        contents at:oldObject put:(count - 1)
     ].
     ^ oldObject
+
+    "Modified: 1.3.1996 / 21:43:18 / cg"
 !
 
 removeAllOccurrencesOf:oldObject ifAbsent:anExceptionBlock
     "Remove all occurrences of oldObject from the collection.
      If it was not present, return the value of the exceptionBlock;
-     otherwise return the number of removes."
+     otherwise return the number of removes.
+
+     WARNING: do not add/remove elements while iterating over the receiver.
+              Iterate over a copy to do this."
 
     |count|
 
@@ -155,6 +173,8 @@
     (count == 0) ifTrue:[^ anExceptionBlock value].
     contents removeKey:oldObject.
     ^ oldObject
+
+    "Modified: 1.3.1996 / 21:43:26 / cg"
 ! !
 
 !Bag methodsFor:'converting'!
@@ -180,20 +200,30 @@
 !Bag methodsFor:'enumerating'!
 
 do:aBlock
-    "evaluate the block for all elements in the collection."
+    "evaluate the block for all elements in the collection.
+
+     WARNING: do not add/remove elements while iterating over the receiver.
+              Iterate over a copy to do this."
 
     contents keysAndValuesDo:[:key :value|
-	value timesRepeat:[
-	    aBlock value:key
-	]
+        value timesRepeat:[
+            aBlock value:key
+        ]
     ]
+
+    "Modified: 1.3.1996 / 21:42:39 / cg"
 !
 
 valuesAndCountsDo:aTwoArgBlock
     "evaluate the block for all distinct elements in the collection,
-     passing both the element and the occurence count as arguments."
+     passing both the element and the occurence count as arguments.
+
+     WARNING: do not add/remove elements while iterating over the receiver.
+              Iterate over a copy to do this."
 
     ^ contents keysAndValuesDo:aTwoArgBlock
+
+    "Modified: 1.3.1996 / 21:42:44 / cg"
 ! !
 
 !Bag methodsFor:'private'!
@@ -243,5 +273,5 @@
 !Bag class methodsFor:'documentation'!
 
 version
-    ^ '$Header: /cvs/stx/stx/libbasic/Bag.st,v 1.16 1995-11-23 17:29:24 cg Exp $'
+    ^ '$Header: /cvs/stx/stx/libbasic/Bag.st,v 1.17 1996-03-01 20:43:49 cg Exp $'
 ! !