$List Add Ordered: Difference between revisions
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<span class="pageSubtitle">Add an item to an ordered $list</span> | <span class="pageSubtitle">Add an item to an ordered $list</span> | ||
<p class=" | <p class="warn"><b>Note: </b>Many $functions have been deprecated in favor of Object Oriented methods. The OO equivalent for the $List_Add_Ordered function is <var>[[AddOrdered (Stringlist function)|AddOrdered]]</var>.</p> | ||
This function adds an item to a (presumably) ordered $list, inserting the item at the proper position to maintain the $list's order. | This function adds an item to a (presumably) ordered $list, inserting the item at the proper position to maintain the $list's order. | ||
<var>$List_Add_Ordered</var> accepts two arguments and returns the item number of the inserted string. It is a | <var>$List_Add_Ordered</var> accepts two arguments and returns the item number of the inserted string. It is a [[Calling Sirius Mods $functions|callable]] $function. | ||
==Syntax== | ==Syntax== | ||
<p class="syntax" | <p class="syntax">[%rc =] $List_Add_Ordered(<span class="term">list</span>, <span class="term">string</span>) | ||
< | |||
</p> | </p> | ||
Where: | |||
<ul> | |||
<li><var class="term">%rc</var> is the item number of the added string.</li> | |||
<var> | <li><var class="term">list</var> is the $list identifier of the $list to which the string is to be added. This is a required argument. </li> | ||
<li><var class="term">string</var> is the string to add to the $list. This is a required argument. </li> | |||
</ul> | |||
< | ==Usage notes== | ||
<ul> | |||
<li>All errors in <var>$List_Add_Ordered</var> result in request cancellation. </li> | |||
</ | |||
<li><var>$List_Add_Ordered</var> always adds the indicated string, even if that string already exists on the $list, but the new item is inserted so that the $list is in EBCDIC order. <var>$List_Add_Ordered</var> assumes that the $list is in EBCDIC order, so it does a pseudo binary search to locate the correct insertion point. <var>$List_Add_Ordered</var> does not validate that the $list is in order and, it it isn't, the insertion point is unpredictable. </li> | |||
<li>While in general it would be more efficient to simply copy and sort (via $ListSort) the input $list, such a technique might be useful if the target $list already has a large number of items. </li> | |||
<li>Because <var>$List_Add_Ordered</var> will insert items into the middle of a $list, it will be susceptible to the same page-splitting, sparse $list leaf page issues as [[$ListIns]]. </li> | |||
</ul> | |||
< | ==Example== | ||
<li>[[Sirius functions]]</li> | The following code builds a sorted output $list from an input $list. | ||
<p class="code">For %i From 1 To $ListCnt(%inlist) | |||
%string = $ListInf(%inlist, %i) | |||
%rc = $List_Add_Ordered(%outlist, %string) | |||
End For | |||
</p> | |||
==Products authorizing {{PAGENAMEE}}== | |||
<ul class="smallAndTightList"> | |||
<li>[[List of $functions|Sirius functions]]</li> | |||
<li>[[Fast/Unload User Language Interface]]</li> | <li>[[Fast/Unload User Language Interface]]</li> | ||
<li>[[Janus Open Client]]</li> | <li>[[Media:JoclrNew.pdf|Janus Open Client]]</li> | ||
<li>[[Janus Open Server]]</li> | <li>[[Media:JosrvrNew.pdf|Janus Open Server]]</li> | ||
<li>[[Janus Sockets]]</li> | <li>[[Janus Sockets]]</li> | ||
<li>[[Janus Web Server]]</li> | <li>[[Janus Web Server]]</li> | ||
<li> | <li>Japanese functions</li> | ||
<li>[[Sir2000 Field Migration Facility]]</li> | <li>[[Media:SirfieldNew.pdf|Sir2000 Field Migration Facility]]</li> | ||
</ul> | </ul> | ||
[[Category:$Functions|$List_Add_Ordered]] | [[Category:$Functions|$List_Add_Ordered]] | ||
Latest revision as of 22:51, 20 September 2018
Add an item to an ordered $list
Note: Many $functions have been deprecated in favor of Object Oriented methods. The OO equivalent for the $List_Add_Ordered function is AddOrdered.
This function adds an item to a (presumably) ordered $list, inserting the item at the proper position to maintain the $list's order.
$List_Add_Ordered accepts two arguments and returns the item number of the inserted string. It is a callable $function.
Syntax
[%rc =] $List_Add_Ordered(list, string)
Where:
- %rc is the item number of the added string.
- list is the $list identifier of the $list to which the string is to be added. This is a required argument.
- string is the string to add to the $list. This is a required argument.
Usage notes
- All errors in $List_Add_Ordered result in request cancellation.
- $List_Add_Ordered always adds the indicated string, even if that string already exists on the $list, but the new item is inserted so that the $list is in EBCDIC order. $List_Add_Ordered assumes that the $list is in EBCDIC order, so it does a pseudo binary search to locate the correct insertion point. $List_Add_Ordered does not validate that the $list is in order and, it it isn't, the insertion point is unpredictable.
- While in general it would be more efficient to simply copy and sort (via $ListSort) the input $list, such a technique might be useful if the target $list already has a large number of items.
- Because $List_Add_Ordered will insert items into the middle of a $list, it will be susceptible to the same page-splitting, sparse $list leaf page issues as $ListIns.
Example
The following code builds a sorted output $list from an input $list.
For %i From 1 To $ListCnt(%inlist) %string = $ListInf(%inlist, %i) %rc = $List_Add_Ordered(%outlist, %string) End For