NAME
    map_array - map an array over a function

    SYNOPSIS
    mixed *map_array(mixed *arr, string fun, object ob, mixed extra)

    Returns an array holding the items of 'arr' mapped through ob->fun(). The function 'fun' in 'ob' is called for each element in 'arr' with that element as parameter. A second parameter 'extra' is sent in each call if given. Principal function:

    foreach (index) arr[index] = ob->fun(arr[index],extra);

    The value returned by ob->fun(arr[.index.], extra) replaces the existing element in the array.