Sort (Arraylist subroutine)

Sort the input Arraylist (Arraylist class)

Sort sorts the method object Arraylist replacing it with the sorted result. The sort is based on one or more sort criteria, each of which consists of a sorting direction (ascending or descending) paired with a sort key (a function that gets applied to an Arraylist item). The sort criteria pairs are passed to SortNew as a SortOrder argument.

Each sort key function (which is applied to the Arraylist items) must operate on the item type and return an intrinsic datatype (Float, String, Longstring, or Unicode) value. The values returned by the function are sorted into ascending or descending order to determine the position of their associated item in the Arraylist.

Syntax

al:Sort[( [sortOrder])]

Syntax terms

al

The input Arraylist object.

sortOrder

One or more SortOrder objects, which consist of an ordering direction for the sort and an attribute, or key, to sort by. The ordering direction and sort key are specified in the form: order(key). The order is either Ascending or Descending, and the key is a function that is applied to each item in the al. The values returned by the function are sorted into ascending or descending order to determine the position of their associated item in the rearranged al. For example: al:sort(descending(length)) The function 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 al declaration and that returns a numeric or string value. This is described further in "Specifying a SortOrder's sort key method".

Usage notes

• If the function applied by Sort returns String or Unicode values, Sort uses the collating sequence of EBCDIC or Unicode, respectively, to determine the ascending or descending alphabetic order of the associated al items. If the function returns a numeric type, numeric comparisons are used.
• If two or more al items have equal values after all sort criteria are applied, Sort places them in the same order in which they appear in the input al.
• The function in the parameter for Sort is a method value, not a User Language expression. That is, you cannot provide a function that itself has an argument (say, ToIntegerPower(2)) as the Sort parameter.
• As of Sirius Mods Version 7.6, the default sortOrder argument is the sortOrder Ascending(This), where This is the identity function value described further in "Using the This function as the Maximum parameter". Therefore, al:sort(ascending(this)) can be specified simply as al:sort. See the "SortNew example".
• Sort is available in Sirius Mods Version 7.3 and later.

Examples

For examples of the Sort method, see "Finding collection maxima and minima, and sorting".

See also

• SortNew which works like Sort but returns a new Arraylist instead of replacing the method object.

Arraylist class FloatNamedArraylist class NamedArraylist class UnicodeNamedArraylist class	List of Arraylist methods List of FloatNamedArraylist methods List of NamedArraylist methods List of UnicodeNamedArraylist methods List of Collection methods	Arraylist methods syntax FloatNamedArraylist methods syntax NamedArraylist methods syntax UnicodeNamedArraylist methods syntax
Notation conventions for methods