ListToItem (Stringlist function)

Convert Stringlist to single delimited Stringlist item (Stringlist class)

This method converts the contents of one Stringlist into a separator-delimited string which is overlayed on a single item of a second Stringlist.

ListToItem is a member of the Stringlist class.

Syntax

%count = sl:ListToItem( strList2, itemNum, [separator])

Syntax terms

%rc

A numeric variable that is set to the number of Stringlist items overlayed on a single item in the output Stringlist (strList2), or it is set to a negative error code if an error has occurred.

%sl

A Stringlist object.

strList2

The Stringlist that contains the item to be overlayed by the delimiter-separated string generated from %sl, the method Stringlist.

itemnum

The number of the item from %strList2 to be overlayed by the delimiter-separated string generated from %sl, the method Stringlist. Each %sl item that does not appear in the delimiter-separated string becomes an item in the resultant Stringlist, %outlist.

separator

The delimiter character or characters to be used in the generated Stringlist item string. This optional argument defaults to comma (.,), and it can be the null string. Specifying separator as a null string is different from not specifying the argument at all, since in the latter case it defaults to a comma.

Usage notes

• All errors in ListToItem result in request cancellation.
• The target item in the output Stringlist is cleared to blanks before the overlay is done. If the target item is too short to hold the input Stringlist items, as many items and their trailing delimiters as will fit are placed in the target item, and the result of the ListToItem method is the number of items copied.
• The delimiter-separated string generated by ListToItem can be longer than 255 bytes; its maximum is 6124 bytes.
• Since no partial Stringlist items are placed into the target item, a good test for success of this method is a comparison of the result of ListToItem with a Count of the input Stringlist:

  if %list1:listToItem(%list2, %n) ne -
  %list1:count then
  ( error code )
  end if
  

  As an example of the use of this method, suppose Stringlist %list1 contained these three items:

  LLL
  MMMMM
  NN
  

  Suppose %list2 contained these two items:

  A,B,C,
  123456789012345678901234567890
  

  If this is the ListToItem invocation:

  %cnt = %list1:listToItem(%list2, 2)
  

  The resulting %list2 has two items, the second of which is blank-padded to 30 characters, and %cnt is set to 3.

  A,B,C,
  LLL,MMMMM,NN,
  

  Suppose Stringlist %list1 contains five items:

  EVERY
  GOOD
  BOY
  DOES
  FINE
  

  And Stringlist %list2 contains these three items, each padded to 22 characters:

  1234567890123456789012
  ***JUNK****
  THE,ITSY,BITSY,SPIDER,
  

  If this is the ListToItem invocation:

  %cnt = %list1:listToItem(%list2, 3, '++')
  

  The resulting %list2 has three items, each still padded to 22 characters, and %cnt is set to 3:

  1234567890123456789012
  ***JUNK****
  EVERY++GOOD++BOY++
  

  The third item, above, contains only three separated entries because there is insufficient space for the item "DOES" and the item delimiter characters.