Class: VirtualDictionaryWithCache

• Inheritance
• Description
• Instance protocol
  • accessing

Inheritance:

   Object
   |
   +--Collection
      |
      +--VirtualDictionary
         |
         +--VirtualDictionaryWithCache

Package:

stx:libbasic2

Category:

Collections-Unordered

Version:

rev: 1.1 date: 2023/05/10 13:19:58

user: cg

file: VirtualDictionaryWithCache.st directory: libbasic2

module: stx stc-classLibrary: libbasic2

Description:

similar to my superclass,
but I remember already encountered and computed values.
Useful if the computation is expensive.

For example,
    VirtualDictionaryWithCache new 
        fetchBlock:[:key | 
            Transcript showCR: e'computing value for {key}...'.
            key squared
        ]
will respond to:
    at:4
with 16.        

when asked again, the remembered value (as per key) will be returned.

Caveat:
    a virtual dictionary does not support:
        size
        do:     (and all other enumeration messages)
    actually it does not behave at all like a dictionary.

copyright
COPYRIGHT (c) 2023 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.

Instance protocol:

 at: aKey ifAbsent: exceptionValue

retrieve a value from this (virtual) dictionary.