MoveFromId (Stringlist subroutine)

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 method is invoked, the source $list is empty, though the $list identifier is still valid.
• MoveFromId discards the original contents of the method Stringlist.
• The MoveFromId method copies to the method Stringlist any image association that is set via $listimg.
• MoveFromid simply moves the pointers to the $list data 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. For example, suppose complex subroutine Summarize takes a $list identifier as its input parameter. Further suppose that the subroutine is rewritten to use Stringlists rather than $lists. 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. 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.