"

 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.

"

Collection subclass:#MappedCollection

	instanceVariableNames:'domain map'

	classVariableNames:''

	poolDictionaries:''

	category:'Collections-Sequenceable'

!

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.

"

!

documentation

"

    MappedCollections represent collections of objects that are indirectly indexed by names.

    There are really two collections involved: domain and a map.  The map maps

    between external names and indices into domain, which contains the

    real association.  In order to work properly, the domain and map objects must

    be instances of a subclass of SequenceableCollection or Dictionary. 

    [author:]

        Claus Gittinger

"

! !

collection:domainCollection map:mapCollection

    "return a new MappedCollection"

    ^ super new setCollection:domainCollection map:mapCollection

!

new

    "report an error; mappedCollections may not be created using new"

    self error:'use collection:map: to create a MappedCollection'

! !

!MappedCollection methodsFor:'accessing'!

add:anObject

    self shouldNotImplement

!

at:key

    ^ domain at:(map at:key)

!

at:key put:anObject

    ^ domain at:(map at:key) put:anObject

!

contents

    |contents|

    contents := Bag new.

    map do:[:key | contents add:(domain at:key)].

    ^ contents

! !

!MappedCollection methodsFor:'copying'!

postCopy

    domain := domain copy.

    map := map copy

! !

!MappedCollection methodsFor:'enumerating'!

collect:aBlock

    "for each element in the receiver, evaluate the argument, aBlock

     and return a new collection with the results"

    |newCollection|

    newCollection := self species new:self size.

    self do:[:each | newCollection add:(aBlock value:each)].

    ^ newCollection

!

do:aBlock

    "evaluate the argument, aBlock for each element"

    map do:[:mapValue | aBlock value:(domain at:mapValue)].

!

select:aBlock

    "return a new collection with all elements from the receiver, for which

     the argument aBlock evaluates to true"

    |newCollection|

    newCollection := self species new:self size.

    self do:[:each |

	(aBlock value:each) ifTrue:[newCollection add:each].

    ].

    ^ newCollection

! !

!MappedCollection methodsFor:'private'!

setCollection:domainCollection map:mapCollection

    domain := domainCollection.

    map := mapCollection

! !

!MappedCollection methodsFor:'queries'!

species

    ^ domain species

! !

!MappedCollection methodsFor:'testing'!

size

    "return the number of elements in the receiver"

    ^ map size

! !

version

! !