From the NannyMUD documentation

LAST CHANGE

2000-12-14

FUNCTION

NAME
        map_array - Apply a function for all elements in an array.


SYNTAX
  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.