"{ Package: 'stx:libbasic2' }"

"{ NameSpace: Smalltalk }"

AutoResizingOrderedCollection subclass:#AutoResizingOrderedCollectionWithDefault

	instanceVariableNames:'defaultValue'

	classVariableNames:''

	poolDictionaries:''

	category:'Collections-Sequenceable'

!

!AutoResizingOrderedCollectionWithDefault class methodsFor:'documentation'!

documentation

"

    I am an ordered collection which automatically resizes if elements

    are added beyond the size. 

    I.e. if at:put: is sent for indexes > the current size, the receiver grows to

    the required index and missing fields are implicitly filled with a default value.

    Queries for non-existing elements are anwered with the default value.

"

!

examples

"

    |coll|

    coll := AutoResizingOrderedCollectionWithDefault newWithDefaultValue:99.

    coll at:4 put:'four'.

    coll at:8 put:'eight'.

    coll at:9

"

! !

!AutoResizingOrderedCollectionWithDefault methodsFor:'accessing'!

at:index

    "fetch an object at index.

     If index is beyond the actual size, return the default value

     (i.e. this is an alias for at:index ifAbsent:[default value])"

    index > self size ifTrue:[^ defaultValue].

    ^ super at:index

!

at:index put:anObject

    "store an object at index.

     If required, grow the receiver to ensure that index is valid"

    |oldSize|

    index > (oldSize := self size) ifTrue:[

        self grow:index.

        self from:oldSize+1 to:index put:defaultValue.

    ].

    super at:index put:anObject

! !

!AutoResizingOrderedCollectionWithDefault methodsFor:'initialization'!

setDefaultValue:v

    defaultValue := v

! !

!AutoResizingOrderedCollectionWithDefault class methodsFor:'documentation'!

version

    ^ '$Header$'

!

version_CVS

    ^ '$Header$'

! !