"

 COPYRIGHT (c) 1989 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.

"

SequenceableCollection subclass:#OrderedCollection

         instanceVariableNames:'contentsArray firstIndex lastIndex'

         classVariableNames:''

         poolDictionaries:''

         category:'Collections-Sequenceable'

!

OrderedCollection comment:'

COPYRIGHT (c) 1989 by Claus Gittinger

              All Rights Reserved

written spring 89 by claus

'!

!OrderedCollection class methodsFor:'documentation'!

documentation

"

    OrderedCollection have ordered elements. Insertion and removal at both ends

    is possible - therefore they can be used for queues and stacks.

    Instance variables:

    contentsArray   <Array>         the actual contents

    firstIndex      <SmallInteger>  index of first valid element

    lastIndex       <SmallInteger>  index of last valid element

"

! !

!OrderedCollection class methodsFor:'instance creation'!

new:size

    "create a new OrderedCollection"

    ^ (self basicNew) initContents:size

!

new

    "create a new OrderedCollection"

    ^ (self basicNew) initContents:10

! !

!OrderedCollection methodsFor:'queries'!

size

    "return the number of elements in the collection"

    ^ lastIndex - firstIndex + 1

!

isFixedSize

    "return true if the receiver cannot grow - this will vanish once

     Arrays and Strings learn how to grow ..."

    ^ false

! !

!OrderedCollection methodsFor:'copying'!

, aCollection

    "return a new collection formed from concatenating the receiver with

     the argument"

    |newCollection|

    newCollection := self species new:(self size + aCollection size).

    self do:[:element |

        newCollection add:element

    ].

    aCollection do:[:element |

        newCollection add:element

    ].

    ^ newCollection

    "#(1 2 3) asOrderedCollection , #(4 5 6) asOrderedCollection"

!

copyWith:newElement

    "return a new collection consisting of a copy of the receivers elements

     plus the argument."

    |newCollection mySize newSize|

    mySize := self size.

    newSize := mySize + 1.

    newCollection := self species new:newSize.

    newCollection grow:newSize.

    newCollection replaceFrom:1 to:mySize with:self startingAt:1.

    newCollection at:newSize put:newElement.

    ^newCollection

    "#(1 2 3 4 5) copyWith:$a"

    "'abcdefg' copyWith:$h"

    "'abcdefg' copyWith:'123'"  "-- will fail: string cannot be stored into string"

    "'abcdefg' copyWith:1"      "-- will fail: integer cannot be stored into string"

!

copy

    "return a new OrderedCollection containing the elements of the receiver."

    "redefinition is a consequence of the implementation with a

     separate array - otherwise we get a shallow copy of the

     contents array, which is not what we want here"

    ^ self copyFrom:1 to:self size

!

copyFrom:start to:stop

    "return a new OrderedCollection containing the elements

     from start to stop."

    |newCollection sz|

    sz := stop - start + 1.

    newCollection := self species new:sz.

    newCollection grow:sz.

    newCollection replaceFrom:1 to:sz with:self startingAt:start.

    ^ newCollection

! !

!OrderedCollection methodsFor:'adding & removing'!

removeFirst

    "remove the first element from the collection; return the element"

    |anObject |

    firstIndex > lastIndex ifTrue:[

        "error if collection is empty"

        self subscriptBoundsError.

        ^ nil

    ].

    anObject := contentsArray at:firstIndex.

    contentsArray at:firstIndex put:nil.

    firstIndex := firstIndex + 1.

    firstIndex > lastIndex ifTrue:[

        "reset to avoid ever growing"

        firstIndex := 1.

        lastIndex := 0 

    ].

    ^ anObject

    "(OrderedCollection withAll:#(1 2 3 4 5)) removeFirst; yourself"

    "(SortedCollection withAll:#(5 4 3 2 1)) removeFirst; yourself"

    "(SortedCollection new) removeFirst"

!

removeLast

    "remove the last element from the collection; return the element"

    |anObject |

    firstIndex > lastIndex ifTrue:[

        "error if collection is empty"

        self subscriptBoundsError.

        ^ nil

    ].

    anObject := contentsArray at:lastIndex.

    contentsArray at:lastIndex put:nil.

    lastIndex := lastIndex - 1.

    firstIndex > lastIndex ifTrue:[

        "reset to avoid ever growing"

        firstIndex := 1.

        lastIndex := 0 

    ].

    ^ anObject

    "(OrderedCollection withAll:#(1 2 3 4 5)) removeLast; yourself"

    "(SortedCollection withAll:#(5 4 3 2 1)) removeLast; yourself"

!

removeFromIndex:startIndex to:stopIndex

    "remove the elements stored under startIndex up to and including

     the elements under stopIndex.

     return the receiver."

    |nDeleted|

    nDeleted := stopIndex - startIndex + 1.

    contentsArray replaceFrom:(firstIndex + startIndex)

                           to:(lastIndex - nDeleted)

                         with:contentsArray 

                   startingAt:(firstIndex + stopIndex + 1).

    contentsArray from:(lastIndex - nDeleted + 1)

                    to:lastIndex

                   put:nil.

    lastIndex := lastIndex - nDeleted.

    firstIndex > lastIndex ifTrue:[

        "reset to avoid ever growing"

        firstIndex := 1.

        lastIndex := 0 

    ]

    "

     #(1 2 3 4 5 6 7 8 9) asOrderedCollection removeFromIndex:3 to:6

    "

!

remove:anObject ifAbsent:exceptionBlock

    "remove the first occurrence of anObject from the collection;

     return the value of exceptionBlock if anObject is not in

     the collection"

    |index "{ Class:SmallInteger }"|

    index := firstIndex.

    [index <= lastIndex] whileTrue:[

        anObject = (contentsArray at:index) ifTrue:[

            contentsArray replaceFrom:index to:(contentsArray size - 1)

                            with:contentsArray startingAt:(index + 1).

            contentsArray at:lastIndex put:nil.

            lastIndex := lastIndex - 1.

            firstIndex > lastIndex ifTrue:[

                "reset to avoid ever growing"

                firstIndex := 1.

                lastIndex := 0 

            ].

            ^ anObject

        ].

        index := index + 1

    ].

    ^ exceptionBlock value

!

add:anObject

    "add the argument, anObject to the end of the collection

     Return the argument, anObject."

    (lastIndex == contentsArray size) ifTrue:[

        self makeRoomAtLast

    ].

    lastIndex := lastIndex + 1.

    contentsArray at:lastIndex put:anObject.

    ^ anObject

    "

     |c|

     c := #(4 3 2 1) asOrderedCollection.

     c add:'here'

    "

!

addFirst:anObject

    "add the argument, anObject to the beginning of the collection.

     Return the argument, anObject."

    (firstIndex == 1) ifTrue:[

        self makeRoomAtFront

    ].

    firstIndex := firstIndex - 1.

    contentsArray at:firstIndex put:anObject.

    ^ anObject

    "

     |c|

     c := #(4 3 2 1) asOrderedCollection.

     c addFirst:'here'

    "

!

add:anObject beforeIndex:index

    "insert the argument, anObject to become located at index.

     Return the argument, anObject."

    self makeRoomAtIndex:(index - firstIndex + 1).

    contentsArray at:(index - firstIndex + 1) put:anObject.

    "

     |c|

     c := #(4 3 2 1) asOrderedCollection.

     c add:'here' beforeIndex:3

    "

!

add:newObject after:oldObject

    "insert the argument, newObject after oldObject.

     If oldObject is not in the receiver, report an error,

     otherwise return the argument, anObject."

    |idx|

    idx := self indexOf:oldObject.

    idx ~~ 0 ifTrue:[

        ^ self add:newObject beforeIndex:(idx + 1).

    ].

    self errorNotFound

    "

     |c|

     c := #(4 3 2 1) asOrderedCollection.

     c add:'here' after:3.

     c add:'here' after:5 

    "

! 

add:newObject before:oldObject

    "insert the argument, newObject before oldObject.

     If oldObject is not in the receiver, report an error,

     otherwise return the argument, anObject."

    |idx|

    idx := self indexOf:oldObject.

    idx ~~ 0 ifTrue:[

        ^ self add:newObject beforeIndex:idx.

    ].

    self errorNotFound

    "

     |c|

     c := #(4 3 2 1) asOrderedCollection.

     c add:'here' before:3.

     c add:'here' before:5 

    "

! !

!OrderedCollection methodsFor:'grow & shrink'!

grow:newSize

    "grow the receiver to newSize"

    |newContents oldLast|

    newSize <= (lastIndex - firstIndex + 1) ifTrue:[

        oldLast := lastIndex.

        lastIndex := firstIndex + newSize - 1.

        contentsArray from:lastIndex + 1 to:oldLast put:nil. 

    ] ifFalse:[

        newContents := Array new:newSize.

        newContents replaceFrom:1 to:(lastIndex - firstIndex + 1) with:contentsArray.

        contentsArray := newContents.

        firstIndex := 1.

        lastIndex := newSize

    ]

! !

!OrderedCollection methodsFor:'accessing'!

at:anInteger

    "return the element at index, anInteger"

    |idx|

    idx := anInteger + firstIndex - 1.

    ((anInteger < 1) or:[idx > lastIndex]) ifTrue:[

        self subscriptBoundsError

    ] ifFalse:[

        ^ contentsArray at:idx

    ]

!

at:anInteger put:anObject

    "set the element at index, to be anInteger"

    |idx|

    idx := anInteger + firstIndex - 1.

    ((anInteger < 1) or:[idx > lastIndex]) ifTrue:[

        self subscriptBoundsError

    ] ifFalse:[

        ^ contentsArray at:idx put:anObject

    ]

!

first

    "return the first element"

    firstIndex <= lastIndex ifTrue:[

        ^ contentsArray at:firstIndex

    ].

    "error if collection is empty"

    self subscriptBoundsError

    "(OrderedCollection withAll:#(1 2 3 4 5)) first"

    "(SortedCollection withAll:#(5 4 3 2 1)) first"

!

last

    "return the last element"

    firstIndex <= lastIndex ifTrue:[

        ^ contentsArray at:lastIndex

    ].

    "error if collection is empty"

    self subscriptBoundsError

    "(OrderedCollection withAll:#(1 2 3 4 5)) last"

    "(SortedCollection withAll:#(5 4 3 2 1)) last"

! !

!OrderedCollection methodsFor:'filling & replacing'!

replaceFrom:start to:stop with:aCollection startingAt:repStart

    "redefined - can be done faster"

    |end|

    end := stop + firstIndex - 1.

    ((start >= 1) and:[end <= lastIndex]) ifTrue:[

    ].

    ^ super replaceFrom:start to:stop with:aCollection startingAt:repStart

! !

!OrderedCollection methodsFor:'private'!

setFirstIndex:newFirstIndex lastIndex:newLastIndex

    "set first and last index"

    firstIndex := newFirstIndex.

    lastIndex := newLastIndex.