"

 COPYRIGHT (c) 1998 by eXept Software AG

              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.

"

"{ Package: 'stx:libbasic' }"

Collection subclass:#KeyedCollection

	instanceVariableNames:''

	classVariableNames:''

	poolDictionaries:''

	category:'Collections-Abstract'

!

!KeyedCollection class methodsFor:'documentation'!

copyright

"

 COPYRIGHT (c) 1998 by eXept Software AG

              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

"

    Abstract superclass for collections which have a key->value mapping.

    This abstract class provides functionality common to those collections,

    without knowing how the concrete class implements things. Thus, all

    methods found here depend on some basic mechanisms to be defined in the

    concrete class. 

    These basic methods are usually defined as #subclassResponsibility here.

    Some methods are also redefined for better performance.

    Subclasses should at least implement:

        at:ifAbsent:        - accessing elements

        removeKey:ifAbsent  - removing

        keysAndValuesDo:    - enumerating

    [author:]

        Claus Gittinger

"

! !

!KeyedCollection class methodsFor:'queries'!

isAbstract

    ^ self == KeyedCollection

! !

!KeyedCollection methodsFor:'accessing'!

at:key

    "return the value stored under akey.

     Raise an error if not found"

    ^ self at:key ifAbsent:[self errorKeyNotFound:key].

    "Modified: / 19.6.1998 / 00:48:27 / cg"

!

at:key ifAbsent:exceptionBlock

    "return the value stored under akey.

     Return the value from evaluating exceptionBlock if not found"

    ^ self subclassResponsibility

    "Created: / 19.6.1998 / 00:48:23 / cg"

!

keyAtValue:value

    "return the key under which value is stored.

     Raise an error if not found"

    ^ self keyAtValue:value ifAbsent:[self errorValueNotFound:value].

    "Modified: / 19.6.1998 / 00:48:27 / cg"

    "Created: / 19.6.1998 / 00:49:16 / cg"

!

keyAtValue:value ifAbsent:exceptionBlock

    "return the key under which value is stored.

     If not found, return the value from evaluating exceptionBlock"

    self keysAndValuesDo:[:elKey :elValue |

        value == elValue ifTrue:[^ elKey]

    ].

    ^ exceptionBlock value

    "Modified: / 19.6.1998 / 00:48:27 / cg"

    "Created: / 19.6.1998 / 00:50:34 / cg"

!

keys

    "return a collection containing the keys of the receiver"

    |keyCollection|

    keyCollection := OrderedCollection new.

    self keysDo:[:aKey |

        keyCollection add:aKey

    ].

    ^ keyCollection

    "Modified: / 19.6.1998 / 00:48:27 / cg"

    "Created: / 19.6.1998 / 00:51:49 / cg"

!

values

    "return a collection containing the values of the receiver"

    |valueCollection|

    valueCollection := OrderedCollection new.

    self do:[:element |

        valueCollection add:element

    ].

    ^ valueCollection

    "Modified: / 19.6.1998 / 00:48:27 / cg"

    "Created: / 19.6.1998 / 00:52:16 / cg"

! !

!KeyedCollection methodsFor:'enumerating'!

do:aBlock

    "evaluate aBlock for each value"

    self keysAndValuesDo:[:elKey :elValue | aBlock value:elValue]

    "Created: / 19.6.1998 / 00:56:24 / cg"

!

findFirstKey:aBlock

    "find and return the first key, for which evaluation of the argument, aBlock

     returns true; return nil if none is detected."

    self keysDo:[:key |

        (aBlock value:key) ifTrue:[^ key].

    ].

    ^ nil

    "Created: 8.10.1996 / 22:01:31 / cg"

    "Modified: 8.10.1996 / 22:02:03 / cg"

!

keysAndValuesDo:aBlock

    "evaluate aBlock for each key and value"

    ^ self subclassResponsibility

    "Created: / 19.6.1998 / 00:56:52 / cg"

!

keysDo:aBlock

    "evaluate aBlock for each key"

    self keysAndValuesDo:[:elKey :elValue | aBlock value:elKey]

    "Created: / 19.6.1998 / 00:56:34 / cg"

! !

!KeyedCollection methodsFor:'removing'!

removeKey:aKey

    "remove key (and the value stored under that key) from the

     receiver; raise an error if no such element is contained"

    ^ self removeKey:aKey ifAbsent:[self errorKeyNotFound:aKey]

    "Created: / 19.6.1998 / 00:53:25 / cg"

    "Modified: / 19.6.1998 / 00:54:02 / cg"

!

removeKey:aKey ifAbsent:exceptionBlock

    "remove key (and the value stored under that key) from the

     receiver; if no such element is contained, return the value

     from evaluating exceptionBlock"

    ^ self subclassResponsibility

    "Created: / 19.6.1998 / 00:53:58 / cg"

! !

!KeyedCollection methodsFor:'testing'!

includesKey:aKey

    "return true, if the argument, aKey is a key in the receiver"

    self keysDo:[:elKey | aKey = elKey ifTrue:[^ true]].

    ^ false

    "Created: / 19.6.1998 / 00:55:05 / cg"

! !

!KeyedCollection class methodsFor:'documentation'!

version

! !