NAME
map_array() - modify an array of elements via application of a function
SYNOPSIS
mixed *map_array(mixed *arr, string fun, object ob, mixed extra);
DESCRIPTION
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. If `arr' is not an array, then 0 will be returned.