$ListRem: Difference between revisions

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<span class="pageSubtitle">Remove item from $list</span>
<span class="pageSubtitle">Remove item from $list</span>


<p class="warn"><b>Note: </b>Most Sirius $functions have been deprecated in favor of Object Oriented methods. The OO equivalent for the $ListRem function is <var>[[RemoveItem (Stringlist function)|RemoveItem]]</var>.</p>
<p class="warn"><b>Note: </b>Many $functions have been deprecated in favor of Object Oriented methods. The OO equivalent for the $ListRem function is <var>[[RemoveItem (Stringlist function)|RemoveItem]]</var>.</p>


This function removes an item from a $list, decrementing the item numbers of all items which follow.  
This function removes an item from a $list, decrementing the item numbers of all items which follow.  
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<li>[[List of $functions|Sirius functions]]</li>
<li>[[List of $functions|Sirius functions]]</li>
<li>[[Fast/Unload User Language Interface]]</li>
<li>[[Fast/Unload User Language Interface]]</li>
<li>[http://m204wiki.rocketsoftware.com/images/4/4a/JoclrNew.pdf Janus Open Client]</li>
<li>[[Media:JoclrNew.pdf|Janus Open Client]]</li>
<li>[http://m204wiki.rocketsoftware.com/images/1/17/JosrvrNew.pdf Janus Open Server]</li>
<li>[[Media:JosrvrNew.pdf|Janus Open Server]]</li>
<li>[[Janus Sockets]]</li>
<li>[[Janus Sockets]]</li>
<li>[[Janus Web Server]]</li>
<li>[[Janus Web Server]]</li>
<li>Japanese functions</li>
<li>Japanese functions</li>
<li>[http://m204wiki.rocketsoftware.com/images/4/4b/SirfieldNew.pdf Sir2000 Field Migration Facility]</li>
<li>[[Media:SirfieldNew.pdf|Sir2000 Field Migration Facility]]</li>
</ul>
</ul>
   
   
[[Category:$Functions|$ListRem]]
[[Category:$Functions|$ListRem]]

Latest revision as of 22:51, 20 September 2018

Remove item from $list

Note: Many $functions have been deprecated in favor of Object Oriented methods. The OO equivalent for the $ListRem function is RemoveItem.

This function removes an item from a $list, decrementing the item numbers of all items which follow.

The $ListRem function accepts two arguments and returns a numeric result. It is a callable $function.

The first argument is a $list identifier. This is a required argument.

The second argument is a number that specifies the item number in the $list. This is a required argument. The number of items remaining in the $list after the removal is returned as the result of this function. If removal of an item makes a CCATEMP $list page empty, that page is removed from use by the $list. Except for sorted lists which are only one page in size, space taken up by the removed item is made available on the $list page. If there are no items remaining after the removal, the $list is deleted.

Syntax

[%RESULT =] $ListRem(list_identifier, item_num)

%result is the number of items remaining in the $list after the removal, or is a negative number if an error has occurred.

Error codes

-5 - Required argument not specified -6 - $List identifier invalid -7 - Item number not found in $list

Usage notes

  • Consecutive $list leaf pages that are made relatively empty with $ListRem will not be merged together. Because of this, heavy use of $ListIns and $ListRem can result in "sparse" $lists which place an unnecessary burden on the buffer pool and CCATEMP. It can also result in an inability to add an item to the end of the $list (via $ListAdd) because of a full pointer page, even though the $list is nowhere near the theoretical capacity for a $list. To make matters worse, $ListCpy does a page-for-page copy of a $list so does not result in any compression of the resultant $list. $List compression can be done using the $List_Copy_Items function.

Products authorizing $ListRem