mapreduce - creating view with couchdb that does grouping and unique counting -

hi have documents so

{    domains: "domain1.com",    ip: "192.168.0.1"  } 

documents may have different or duplicate domains/ips

i want view give me list of

domain1 => unique ip count domain
domain2 => unique ip count domain
etc..

i know how a:

domain => ip count map/reduce:

 "map": "function(doc) { emit(doc.domains, 1) }",<br/>  "reduce": "_sum" 

and group=true parameter

but can't figure out how to a:

domain => unique ip count style list

cheers assistance, sorry english

write view map function , no reduce function

function(doc) {   if (doc.domains) emit(doc.domains, doc.ip); } 

then create list function counts unique entries.

function(head, req) {   var ips = new array();   while (row = getrow()) {     if (ips.indexof(row) != -1) {        ips.push(row.value);     }   }   send(ips.length); } 

warning: code not tested, might contain bugs.

finally call list function on map view key set domain want. note solution won't perform if have large number of ips per domain.