$ListRem: Difference between revisions

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<span class="pageSubtitle"><section begin="desc" />Remove item from $list<section end="desc" /></span>
<span class="pageSubtitle"><section begin="desc" />Remove item from $list<section end="desc" /></span>


<p class="warning">Most Sirius $functions have been deprecated in favor of Object Oriented methods. The OO equivalent for the $ListRem function is [[to be entered]].</p>
<p class="warning">Most Sirius $functions have been deprecated in favor of Object Oriented methods. The OO equivalent for the $ListRem function is the [[RemoveItem (Stringlist function)]].</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.  


The $ListRem function accepts two arguments and returns a numeric result. It is a callable $function (:hdref refid=callfun.).  
The $ListRem function accepts two arguments and returns a numeric result. It is a callable $function (see [[Calling Sirius Mods $functions]]).  


The first argument is a $list identifier. This is a required argument.  
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. p. 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.
The second argument is a number that specifies the item number in the $list. This is a required argument. p. 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==
==Syntax==
<p class="syntax"><section begin="syntax" /> [%RESULT =] $ListRem(list_identifier, item_num)
<p class="syntax"><section begin="syntax" /> [%RESULT =] $ListRem(list_identifier, item_num)
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</p>
</p>
<p class="caption">%RESULT is the number of items remaining in the $list after the removal, or is a negative number if an error has occurred.</p>
<p class="caption">%RESULT is the number of items remaining in the $list after the removal, or is a negative number if an error has occurred.</p>
<p class="code">  
<p class="code">  
  -5 - Required argument not specified
  -5 - Required argument not specified
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</p>
</p>


 
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.<p>
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&CQ. $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, documented in :hdref refid=listcit..<p>


<ul class="smallAndTightList">
<ul class="smallAndTightList">
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<p class="caption">Products authorizing $ListRem
<p class="caption">Products authorizing $ListRem
</p>
</p>


[[Category:$Functions|$ListRem]]
[[Category:$Functions|$ListRem]]

Revision as of 15:53, 10 February 2011

<section begin="desc" />Remove item from $list<section end="desc" />

Most Sirius $functions have been deprecated in favor of Object Oriented methods. The OO equivalent for the $ListRem function is the RemoveItem (Stringlist function).

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 (see Calling Sirius Mods $functions).

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. p. 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

<section begin="syntax" /> [%RESULT =] $ListRem(list_identifier, item_num) <section end="syntax" />

$ListRem Function

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

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

$ListRem Error Codes

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

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