MoveFromId (Stringlist subroutine): Difference between revisions
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{{Template:Stringlist:MoveFromId subtitle}} | {{Template:Stringlist:MoveFromId subtitle}} | ||
This method moves data ($list items) from a $list to a <var> | This method moves data (<var>$list</var> items) from a <var>$list</var> to a <var>stringlist</var>. <var>MoveFromId</var> is a subroutine that accepts one argument: the <var>$list</var> identifier of the <var>$list</var> from which data is to be moved. For more information about <var>$list</var> identifiers, see the <var class="Product">[[Sirius Functions Reference Manual]]</var>. | ||
==Syntax== | ==Syntax== | ||
| Line 10: | Line 10: | ||
<td>A <var>Stringlist</var> object.</td></tr> | <td>A <var>Stringlist</var> object.</td></tr> | ||
<tr><th>listid</th> | <tr><th>listid</th> | ||
<td>The $list identifier of the $list from which data is to be moved.</td></tr> | <td>The <var>$list</var> identifier of the $list from which data is to be moved.</td></tr> | ||
</table> | </table> | ||
==Usage notes== | ==Usage notes== | ||
<ul><li>All errors in <var>MoveFromId</var> result in request cancellation.<li>After the MovefromId | <ul><li>All errors in <var>MoveFromId</var> result in request cancellation.<li>After the <var>MovefromId</var> is invoked, the source <var>$list</var> is empty, although the <var>$list</var> identifier is still valid.<li><var>MoveFromId</var> discards the original contents of the method <var>stringlist</var>.<li><var>MoveFromId</var> copies to the method <var>stringlist</var> any image association that is set via <var>$listimg</var>.<li><var>MoveFromid</var> simply moves the internal <var>$list</var> data pointers to the object <var>stringlist</var>. It does '''not''' actually perform any data movement; therefore, it is extremely efficient.<li><var>MoveFromid</var> is intended to facilitate migration to <var>stringlist</var>s of existing applications that use <var>$lists</var>.<li> <var>stringlists</var> should always be used in preference to <var>$lists</var>, so <var>MoveFromId</var> is provided only for the migration of existing <var>$list</var> applications to the use of <var>Stringlist</var>s.</ul> | ||
The following code illustrates how this can be accomplished: | |||
==Examples== | |||
Suppose complex subroutine Summarize takes a <var>$list</var> identifier as its input parameter. Further suppose that the subroutine is rewritten to use <var>Stringlist</var>s rather than <var>$list</var>. The following code illustrates how this can be accomplished: | |||
<p class="code">subroutine summarize(%listId is float) | <p class="code">subroutine summarize(%listId is float) | ||
| Line 21: | Line 23: | ||
%list = new | %list = new | ||
%list:moveFromid(%listId) | %list:moveFromid(%listId) | ||
... | ... | ||
%list:moveToid(%listId) | %list:moveToid(%listId) | ||
return | return | ||
</p> | </p> | ||
Of course, if the subroutine "forgets" to restore the input $list contents with | Of course, if the subroutine "forgets" to restore the input <var>$list</var> contents with <var>MoveToId</var>, the input <var>$list</var> remains empty at the end of the subroutine. | ||
[[Category:Stringlist methods|MoveFromId subroutine]] | [[Category:Stringlist methods|MoveFromId subroutine]] | ||
Revision as of 08:32, 26 January 2011
Move data from $list to Stringlist (Stringlist class)
This method moves data ($list items) from a $list to a stringlist. MoveFromId is a subroutine that accepts one argument: the $list identifier of the $list from which data is to be moved. For more information about $list identifiers, see the Sirius Functions Reference Manual.
Syntax
sl:MoveFromId( listId)
Syntax terms
| sl | A Stringlist object. |
|---|---|
| listid | The $list identifier of the $list from which data is to be moved. |
Usage notes
- All errors in MoveFromId result in request cancellation.
- After the MovefromId is invoked, the source $list is empty, although the $list identifier is still valid.
- MoveFromId discards the original contents of the method stringlist.
- MoveFromId copies to the method stringlist any image association that is set via $listimg.
- MoveFromid simply moves the internal $list data pointers to the object stringlist. It does not actually perform any data movement; therefore, it is extremely efficient.
- MoveFromid is intended to facilitate migration to stringlists of existing applications that use $lists.
- stringlists should always be used in preference to $lists, so MoveFromId is provided only for the migration of existing $list applications to the use of Stringlists.
Examples
Suppose complex subroutine Summarize takes a $list identifier as its input parameter. Further suppose that the subroutine is rewritten to use Stringlists rather than $list. The following code illustrates how this can be accomplished:
subroutine summarize(%listId is float) %list is object stringList %list = new %list:moveFromid(%listId) ... %list:moveToid(%listId) return
Of course, if the subroutine "forgets" to restore the input $list contents with MoveToId, the input $list remains empty at the end of the subroutine.