Class: Association

• Inheritance
• Description
• Related information
• Class protocol
  • instance creation
• Instance protocol
  • accessing
  • collection mimicri
  • comparing
  • printing & storing
  • queries

Inheritance:

   Object
   |
   +--Magnitude
      |
      +--LookupKey
         |
         +--Association
            |
            +--Class::SimulatedClassPool::SimulatedVariableBinding

Package:

stx:libbasic

Category:

Collections-Support

Version:

rev: 1.27 date: 2017/02/22 18:02:09

user: cg

file: Association.st directory: libbasic

module: stx stc-classLibrary: libbasic

Author:

Claus Gittinger

Description:

Associations are a key-value pair; conceptionally, they are the elements of 
Dictionaries - storing value under the key. (However, the real implementation
of Dictionary is different).
Taken by itself, an association is not very useful.

[Instance variables:]

    key             <Object>        the key (inherited)
    value           <Object>        the value

Related information:

    Dictionary
    IdentityDictionary

Class protocol:

 key: aKey value: aValue

return a new Association

Instance protocol:

 key: aKey value: aValue

set both the key and value of the receiver.
Return the receiver

 value

return the value of the association

 value: anObject

set the value of the receiver to be anObject.
Return the receiver

 keysAndValuesDo: aBlock

evaluate the argument, aBlock for each element in the collection.
Pass both index and element to the block.
Added here to allow for an association to be added via the comma operation
to an existing dictionary

 = anAssociation

return true if the receiver equals the argument.
Notice, that this compares both key AND value.
Time will show if this is ok.

 hash

return an integer useful for hashing on the receiver;
redefined since = is redefined here.

 displayOn: aGCOrStream

Compatibility
append a printed desription on some stream (Dolphin, Squeak)
OR:
display the receiver in a graphicsContext at 0@0 (ST80).
This method allows for any object to be displayed in some view
(although the fallBack is to display its printString ...)

 printOn: aStream

append a printed representation of the receiver to aStream

 storeOn: aStream

append a string representing an expression to reconstruct the receiver
to aStream.

 isAssociation

return true, if the receiver is some kind of association;
true is returned here - the method is redefined from Object.