.\"partitions a set of objects according to the action of a separator function
.TH unique_array 3 "5 Sep 1994" MudOS "LPC Library Functions"

.SH NAME
unique_array() - partitions an array of objects into groups

.SH SYNOPSIS
mixed unique_array( object *obarr, string separator, void | mixed skip );
mixed unique_array( mixed *arr, function f, void | mixed skip );

.SH DESCRIPTION
Groups objects together for which the `separator' function returns the same 
value. `obarr' should be an array of objects, other types are ignored.
The `separator' function is called only once in each object in `obarr'.
THe optional `skip' parameter enables a pre-filter on `obarr', skipping
elements which match `skip'.
The second form works a bit differently.  each element of the array is
passed to f and the elements are partitioned based on the return value
of f.  In particular, the array does not need to be composed of
objects.

.SH RETURN VALUE
The return value is an array of arrays of objects on the form:
.PP
.nf
     ({
         ({Same1:1, Same1:2, Same1:3, .... Same1:N }),
         ({Same2:1, Same2:2, Same2:3, .... Same2:N }),
         ({Same3:1, Same3:2, Same3:3, .... Same3:N }),
                       ....
                       ....
         ({SameM:1, SameM:2, SameM:3, .... SameM:N }),
     })