FindNextItemNumber (GenericNamedArraylist function)

From m204wiki
Jump to navigation Jump to search

Item number of next item that matches some selection criteria (FloatNamedArraylist, NamedArraylist, and UnicodeNamedArraylist classes)


FindNextItemNumber searches "forward" in a FloatNamedArraylist, NamedArraylist, or UnicodeNamedArraylist to find and return the item number of the next item that matches a specified criterion. The criterion is supplied by the SelectionCriterion object that is a required FindNextItemNumber parameter. If no item satisfies the criterion, the method returns a zero.

Syntax

%number = anyNal:FindNextItemNumber( selectionCriterion, [Start= number])

Syntax terms

%number A numeric variable to contain the item number of the item that is located by the search.
anyNal The FloatNamedArraylist, NamedArraylist or UnicodeNamedArraylist method object.
selectionCriterion A SelectionCriterion object, which is a relational expression that is applied to a anyNal item value to determine whether the value satisfies the expression. The expression consists of a function, an operator, and a numeric or string value.

For example, GT(this, 11) is the criterion this > 11, where This is an identity function value that simply returns the item's value. The item number of the first item tested by FindNextItemNumber 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 anyNal declaration and that returns a numeric or string value. This is described further in "Specifying a SelectionCriterion's parameters".

Start The number of the item after which to begin the search. If the 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 FloatNamedArraylist, NamedArraylist or UnicodeNamedArraylist. For an array list of three items, number may be 0, 1, 2, or 3.

This is an optional, name required, argument which 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 FloatNamedArraylist, NamedArraylist or UnicodeNamedArraylist, the request is cancelled. If the value of Start is equal to the number of items, then FindNextItemNumber returns a zero.
  • FindNextItemNumber is available in Sirius Mods Version 7.6 and later.

Examples

  1. In the following fragment, two FindNextItemNumber calls and one FindPreviousItemNumber call are applied to a collection of objects of the staff class that is defined in the request in the "FindNextItem Examples" section:

    %old is namedArraylist of object staff %old = new %old('Jim') = newf('Red', 'employed') %old('Jed') = newf('Black', 'retired') %old('Jan') = newf('Green', 'employed') %old('Jud') = newf('Brown', 'retired') %old('Jon') = newf('White', 'retired') %sel1 is object selectioncriterion for object staff %sel2 is object selectioncriterion for object staff %n is float %sel1 = gt(name, 'Mud') %sel2 = and(gt(name, 'Mud'), eq(status, 'retired')) %n = %old:findNextItemNumber(%sel1, start=1) print %old:nameByNumber(%n) %n = %old:findNextItemNumber(%sel2) print %old:nameByNumber(%n) %n = %old:findPreviousItemNumber(lt(name, 'Mud'), start=%n) print %old:nameByNumber(%n)

    The result is:

    Jim Jon Jed

  2. The following request contains two FindNextItemNumber calls and one FindPreviousItemNumber call:

    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 %n is float %sel = LT(this, 'C') %n = %k:findNextitemNumber(%sel) print %k:nameByNumber(%n) %n = %k:findNextItemNumber(%sel, start=%n) print %k:nameByNumber(%n) %n = %k:findPreviousItemNumber(EQ(this, 'Leo'), start=%n) print %k:nameByNumber(%n) end

    The result is:

    §Dec §Nov §Apr

See also

  • FindPreviousItemNumber is identical to FindNextItemNumber except that it searches backward in the FloatNamedArraylist, NamedArraylist or UnicodeNamedArraylist.