Class: KeyedCollection

• Inheritance
• Description
• Class protocol
  • queries
• Instance protocol
  • accessing
  • enumerating
  • removing
  • testing

Inheritance:

   Object
   |
   +--Collection
      |
      +--KeyedCollection
         |
         +--MethodDictionary
         |
         +--RBSmallDictionary

Package:

stx:libbasic

Category:

Collections-Abstract

Version:

rev: 1.7 date: 2010/01/29 16:42:18

user: cg

file: KeyedCollection.st directory: libbasic

module: stx stc-classLibrary: libbasic

Author:

Claus Gittinger

Description:

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

Class protocol:

 isAbstract

Return if this class is an abstract class.
True is returned for KeyedCollection here; false for subclasses.
Abstract subclasses must redefine again.

Instance protocol:

 at: key

return the value stored under akey.
Raise an error if not found

 at: key ifAbsent: exceptionBlock

return the value stored under akey.
Return the value from evaluating exceptionBlock if not found

** This method raises an error - it must be redefined in concrete classes **

 keyAtValue: value

return the key under which value is stored.
Raise an error if not found

 keyAtValue: value ifAbsent: exceptionBlock

return the key under which value is stored.
If not found, return the value from evaluating exceptionBlock

 keys

return a collection containing the keys of the receiver

 do: aBlock

evaluate aBlock for each value

 findFirstKey: aBlock

find and return the first key, for which evaluation of the argument, aBlock
returns true; return nil if none is detected.

 keysAndValuesDo: aBlock

evaluate aBlock for each key and value

** This method raises an error - it must be redefined in concrete classes **

 keysDo: aBlock

evaluate aBlock for each key

 removeKey: aKey

remove key (and the value stored under that key) from the
receiver; raise an error if no such element is contained

 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

** This method raises an error - it must be redefined in concrete classes **

 includesIdenticalKey: aKey

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

 includesKey: aKey

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