Puppet prefix function does not seem to prefix the result -

i trying provision splunk alert cluster of kafkas. have code, , hiera data "kafka_hosts" map hostnames keys.

$kafka_hosts = keys(hiera('kafka_hosts')) $splunk_host_expresssions = prefix($kafka_hosts,'host=') $splunk_hosts_expression = join($splunk_host_expresssions,' or ') 

$splunk_hosts_expression comes out host names separated or. prefix host= not turn up.

the result want is:

host=a.example.org or host=b.example.org or host=c.example.org 

puppet version 2.7