Morgengrauner Dokumentation

Dateipfad: /home/mud/mudlib/doc//efun/filter.eng
filter(E)
SYNOPSIS
     mixed *filter(mixed *arr, string fun, string|object ob
                         [, mixed extra, ...])
     mixed *filter(mixed *arr, closure cl [, mixed extra, ...])
     mixed *filter(mixed *arr, mapping map [, mixed extra, ...])

DESCRIPTION
        Returns an array holding the items of arr filtered through
        ob->fun(element, extra, ...), the closure cl, or the mapping map.
        The function 'fun' in 'ob' resp. the closure 'cl' is called
        for each element in arr with that element as parameter. The
        extra and following parameters are in each call if given.
        The mapping 'map' is likewise indexed by each element.
        If ob->fun(arr[index], extra) returns != 0 resp.
        map[arr[index]] exists, the element is included in the
        returned array.

        If arr is not an array, an error occurs.

        The extra argument(s) are optional and must not be protected
        references like &(i[0]).
        If  is omitted, or neither a string nor an object, it
        defaults to this_object().

        Since 3.2.1@36, the second arg can also be a mapping. Then
        only the elements of the array which belong to the map (as
        keys) will be returned (i.e. map[arr[index]] != 0).

EXAMPLE
        int check_if_idle(object user) { return query_idle(user); }

        ...

        object *idle_users;

        idle_users = filter(users(), "check_if_idle");
        /* equivalent but smaller and faster */
        idle_users = filter(users(), #'query_idle );

        Now idle_users contains all users that have been idle for more
        than 1 second.

SEE ALSO:
        Similar filter:	filter(E), filter_object(E), filter_indices(E)
        Mapping:	map(E), map_objects(E), map_indices(E)
        Related:	sort_aray(E), unique_array(E)


29.10.2006 Zesstra

zurück zur Übersicht