FindNextItem (UnicodeNamedArraylist function)

<section begin=dpl_desc/>Find matching list item<section end=dpl_desc/>

FindNextItem is a member of the UnicodeNamedArraylist class.

This function searches “forward” in the UnicodeNamedArraylist to find and return the next item that matches a specified criterion. The criterion is supplied by the SelectionCriterion object that is a required FindNextItem parameter. If no item satisfies the criterion, the request is cancelled and an ItemNotFound exception (?? refid=itemnfe.) is thrown.

Syntax

  %item = %unamrayl:FindNextItem(criterion        -
                                 [, Start=itemnum])

Syntax Terms

%item

A variable of the type of the items in the UnicodeNamedArraylist to contain the item that is located by the search.

%unamrayl

A UnicodeNamedArraylist object.

criterion

A SelectionCriterion object, which is a relational expression that is applied to a %unamrayl item value to determine whether the value satisfies the expression. The expression consists of a function, an operator, and a User Language intrinsic type (numeric, string, or Unicode) value. For example, GT(this, 1) is the criterion this > 1, where this is an identity function that simply returns the item's value. The first item tested by FindNextItem that satisfies this expression is the method's return value. The function in the criterion is a method value (a method or class member name literal, or a method variable) for a method that operates on items of the type specified on the %unamrayl declaration and that returns an intrinsic value. This is described further in "Specifying a SelectionCriterion's parameters".

Start= itemnum

The number of the item after which to begin the search. If the itemnum value of Start is 2, item 3 is the first item considered. The value of Start may be 0 through the number of items in the UnicodeNamedArraylist. For a UnicodeNamedArraylist of three items, itemnum may be 0, 1, 2, or 3. This is an optional argument, and it defaults to 0. If you specify a value, the parameter name Start is required.

Usage Notes

• If the value of Start is greater than the number of items in the UnicodeNamedArraylist, the request is cancelled. If the value of Start is equal to the number of items, the request is cancelled, but an ItemNotFound exception is thrown.
• FindPreviousItem is identical to FindNextItem except that it searches backward in the UnicodeNamedArraylist.

Examples

The following request contains one FindNextItem call and one FindPreviousItem call. The FindPreviousItem call finds no matching item:

    Begin

    %k  is unicodeNamedArraylist of longstring
    %k = new
    %k('§Jan':u) = 'Orion'
    %k('§Apr':u) = 'Leo'
    %k('§Mar':u) = 'Cancer'
    %k('§Jun':u) = 'Ursa Minor'
    %k('§Nov':u) = 'Andromeda'
    %k('§Dec':u) = 'Aries'
    %k('§Feb':u) = 'Canis Major'

    %sel is object selectionCriterion for longstring
    %sel2 is object selectionCriterion for longstring
    %sel = OR(LT(this, 'C'), EQ(this, 'Taurus'))
    %sel2 = EQ(this, 'Taurus')

    Print %k:findNextitem(%sel)
    Print %k:findPreviousitem(%sel2)

    End

The result is:

    Aries
    CANCELLING REQUEST: MSIR.0750: Class UNICODENAMEDARRAYLIST,
    function FINDNEXTITEM: ITEMNOTFOUND exception: no items match
    SelectionCriterion in line 31