--- a/SortedCollection.st	Sat Jan 08 17:18:40 1994 +0100
+++ b/SortedCollection.st	Sat Jan 08 17:24:16 1994 +0100
@@ -30,7 +30,7 @@
 while [:a :b | a > b] defines descening order.
 The default sortBlock for SortedCollections is the first one.
 
-$Header: /cvs/stx/stx/libbasic/SortedCollection.st,v 1.4 1993-12-11 00:58:06 claus Exp $
+$Header: /cvs/stx/stx/libbasic/SortedCollection.st,v 1.5 1994-01-08 16:23:33 claus Exp $
 '!
 
 !SortedCollection class methodsFor:'initialization'!
@@ -138,10 +138,9 @@
     "add the argument, anObject at the proper place in the
      receiver. Returns the argument, anObject."
 
-    |sz index|
+    |index|
 
-    sz := self size.
-    sz == 0 ifTrue:[
+    lastIndex < firstIndex "i.e. self size == 0" ifTrue:[
         super add:anObject
     ] ifFalse:[
         index := self findIndexFor:anObject. 
@@ -154,7 +153,7 @@
 !SortedCollection methodsFor:'converting'!
 
 asSortedCollection
-    "retrun the receiver as a sorted collection"
+    "return the receiver as a sorted collection"
 
     "could be an instance of a subclass..."
     self class == SortedCollection ifTrue:[
@@ -170,10 +169,11 @@
      Redefined, since due to beeing sorted, the inclusion check can
      be done with log-n compares i.e. much faster."
 
-    |index|
+    |index "{ Class: SmallInteger }"|
 
     index := self findIndexFor:anObject.
-    ^ (index <= self size) and:[(contentsArray at:index) = anObject]
+    ((index < firstIndex) or:[index > lastIndex]) ifTrue:[^ false].
+    ^ (contentsArray at:index) = anObject
 
     "#(7 3 9 10 99) asSortedCollection includes:50"
     "#(7 3 9 10 99) asSortedCollection includes:10"
@@ -189,10 +189,10 @@
      tally      "{ Class: SmallInteger }" |
 
     index := self findIndexFor:anObject.
-    mySize := self size.
-    index > mySize ifTrue:[^ 0].
+    ((index < firstIndex) or:[index > lastIndex]) ifTrue:[^ 0].
+
     tally := 0.
-    [(index <= mySize) and:[(contentsArray at:index) = anObject]] whileTrue:[
+    [(index <= lastIndex) and:[(contentsArray at:index) = anObject]] whileTrue:[
         tally := tally + 1.
         index := index + 1
     ].
@@ -240,7 +240,8 @@
 findIndexFor:anObject
     "search the index at which to insert anObject. Can also be used
      to search for an existing element by checking if the element at
-     the returned index is the one we look for."
+     the returned index is the one we look for.
+     The returned index is a physical one, for accessing contentsArray."
 
     |low    "{ Class: SmallInteger}"
      high   "{ Class: SmallInteger}"
@@ -251,7 +252,7 @@
     high := lastIndex.
     [low <= high] whileTrue:[
         middle := (low + high) // 2.
-        element := super at:middle.
+        element := contentsArray at:middle.
         (sortBlock value:element value:anObject) ifTrue:[
             "middleelement is smaller than object"
             low := middle + 1
@@ -262,5 +263,4 @@
     ^ low
 
     "#(1 2 3 4 7 99 1313 981989 898989898) asSortedCollection findIndexFor:50"
-
 ! !