"
COPYRIGHT (c) 1993 by Claus Gittinger
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.
"
Set subclass:#IdentitySet
instanceVariableNames:''
classVariableNames:''
poolDictionaries:''
category:'Collections-Unordered'
!
IdentitySet comment:'
COPYRIGHT (c) 1993 by Claus Gittinger
All Rights Reserved
same as a Set but compares elements using == (i.e. they must be identical
- not just equal in structure).
Since compare is on identity, hashing is also done via
identityHash instead of hash.
$Header: /cvs/stx/stx/libbasic/IdentitySet.st,v 1.3 1993-10-13 00:16:12 claus Exp $
written jan 93 by claus
'!
!IdentitySet methodsFor:'private'!
find:key ifAbsent:aBlock
"Look for the key in the receiver. If it is found, return
the index of the slot containing the key, otherwise
return the value of evaluating aBlock.
Redefined to compare for identity instead of equality"
|index "{ Class:SmallInteger }"
length startIndex probe |
length := contentsArray basicSize.
startIndex := key identityHash \\ length + 1.
index := startIndex.
[true] whileTrue:[
probe := (contentsArray basicAt:index).
probe == key ifTrue:[^ index].
probe isNil ifTrue:[^ aBlock value].
index == length ifTrue:[
index := 1
] ifFalse:[
index := index + 1
].
index == startIndex ifTrue:[
^ aBlock value
]
]
!
findElementOrNil:key
"Look for the key in the receiver. Redefined to compare for
identity instead of equality"
|index "{ Class:SmallInteger }"
length startIndex probe |
length := contentsArray basicSize.
startIndex := key identityHash \\ length + 1.
index := startIndex.
[true] whileTrue:[
probe := contentsArray basicAt:index.
(probe isNil or: [key == probe]) ifTrue:[^ index].
index == length ifTrue:[
index := 1
] ifFalse:[
index := index + 1
].
index == startIndex ifTrue: [
^ self grow findElementOrNil:key
]
]
! !