Class: IdentitySet

• Inheritance
• Description
• Instance protocol
  • adding & removing
  • converting
  • copying
  • private
  • queries
  • set operations

Inheritance:

   Object
   |
   +--Collection
      |
      +--Set
         |
         +--IdentitySet
            |
            +--SemaphoreSet
            |
            +--SignalSet
            |
            +--WeakIdentitySet

Package:

stx:libbasic

Category:

Collections-Unordered

Version:

rev: 1.47 date: 2023/12/21 15:05:26

user: stefan

file: IdentitySet.st directory: libbasic

module: stx stc-classLibrary: libbasic

Description:

same as a Set but compares elements using == 
(i.e. they must be identical - not just equal in structure).
Since compare is on identity (using ==), hashing is also done via
#identityHash instead of #hash.

copyright
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.

Instance protocol:

 removeIdentical: oldObject ifAbsent: exceptionBlock

remove oldObject from the collection and return it.
If it was not in the collection return the value of exceptionBlock.
Uses identity compare (==) to search for an occurrence.

WARNING: do not remove elements while iterating over the receiver.

 safeRemoveIdentical: oldObject ifAbsent: exceptionBlock

remove oldObject from the collection and return it.
If it was not in the collection return the value of exceptionBlock.
Uses identity compare (==) to search for an occurrence.

 asIdentitySet

return the receiver as an IdentitySet

 asNewIdentitySet

make sure to return myself as a unique new IdentitySet

Usage example(s):

|s| s := #(1 2 3 4) asIdentitySet. self assert:(s ~~ s asNewIdentitySet). self assert:(s = s asNewIdentitySet).

 copyWithout: anElement

return a new collection consisting of a copy of the receiver, with
ALL elements equal to elementToSkip are left out.
No error is reported, if elementToSkip is not in the collection.

Usage example(s):

#(1 2 3 4 5 6 7) asSet copyWithout:5

 collisionsFor: key

Return the number of searches - 1 required for key

 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

 findIdentical: key ifAbsent: aBlock

IdentitySet does identity compare anyway...

 findKeyOrNil: key

Look for the key in the receiver.
If it is found, return return the index of the first unused slot.
Grow the receiver, if key was not found, and no unused slots were present

Warning: an empty slot MUST be filled by the sender - it is only to be sent
by at:put: / add: - like methods.

 findKeyOrNilOrDeletedEntry: key

Look for the key in the receiver.
If it is found, return return the index of the first unused slot.
Grow the receiver, if key was not found, and no unused slots were present

 hashFor: aKey

return an initial index given a key.

 includesIdentical: anObject

for identitySet, the #includes: test already tests for identity

 \ aCollection

return a new set containing all elements of the receiver,
which are NOT also contained in the aCollection
For large collections you better use a Set for aCollection.
Redefined here to do identity comparison.

Usage example(s):

#(0 1 2 3 4 5 6 7 8 9) asIdentitySet \ #(1 2 3) asSet #(0 1 2 3 4 5 6 7 8 9) asIdentitySet \ #(1 2 3) (SortedSet withAll:#(99 0 1 2 3 4 5 6 7 8 9)) \ #(1 2 3)