Class: HistoryCollection

• Inheritance
• Description
• Class protocol
  • defaults
  • instance creation
• Instance protocol
  • accessing
  • adding
  • enumerating
  • private

Inheritance:

   Object
   |
   +--Collection
      |
      +--SequenceableCollection
         |
         +--HistoryCollection
            |
            +--HistoryCollectionWithoutDuplicates

Package:

stx:libbasic2

Category:

Collections-Sequenceable

Version:

rev: 1.10 date: 2023/12/19 15:45:39

user: cg

file: HistoryCollection.st directory: libbasic2

module: stx stc-classLibrary: libbasic2

Description:

I am like an OrderedCollection, but when an entry is added,
I will check my size and remove the oldest entry.
Thus keeping only the N newest added entries.
An alternative name could have been LeastRecentlyUsedCollection or LRUCollection.

Useful for history of recent messages.

    |h|

    h := HistoryCollection new:10.
    h addAll:(1 to:10).
    Transcript showCR:h.
    h addAll(11 to:15).
    Transcript showCR:h.
    h addAll(16 to:20).
    Transcript showCR:h.

or recently used files.
    |h|

    h := HistoryCollection new:10.
    h mostRecentFirst:true.
    h addAll:(1 to:10).
    Transcript showCR:h.
    h add:5.
    Transcript showCR:h.
    h add:1.
    Transcript showCR:h.
    h addAll(11 to:15).
    Transcript showCR:h.
    h addAll(16 to:20).
    Transcript showCR:h.

copyright
COPYRIGHT (c) 2020 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.

Class protocol:

 defaultSizeLimit

 new

(comment from inherited method)
return an instance of myself without indexed variables

 new: sizeLimit

(comment from inherited method)
return an instance of myself with anInteger indexed variables

Instance protocol:

 at: index

(comment from inherited method)
return the indexed instance variable with index, anInteger;
this method can be redefined in subclasses.

 mostRecentFirst

if true, the order is reversed
(affects enumeration).
For backward compatibility, the default is oldest first (do not change)

 mostRecentFirst: aBoolean

if true, the order is reversed
(affects enumeration).
For backward compatibility, the default is oldest first

 size

(comment from inherited method)
return the number of elements in the collection.
concrete implementations must define this

 sizeLimit

 sizeLimit: anInteger

Modified (format): / 17-07-2020 / 13:39:59 / cg

 add: anEntry

(comment from inherited method)
append the argument, anObject to the collection.
Return the argument, anObject.

Notice that this modifies the receiver, NOT a copy.
Also note that it may be a slow operation for some collections,
due to the grow:-message, which is inefficient for fixed size
collections (i.e. for Strings and Arrays it is not recommended).

 addFirst: anEntry

please only use add:

 removeLast

(comment from inherited method)
remove the last element of the receiver and return it.

Notice that this modifies the receiver, NOT a copy.
Also note that it may be a slow operation for some collections,
due to the grow:-message, which is inefficient for fixed size
collections (i.e. for Strings and Arrays it is not recommended).

 do: aBlock

(comment from inherited method)
evaluate the argument, aBlock for every element in the collection in
sequence order.

 initializeWithSizeLimit: limitArg