# concat data expression

# empty configs are not accepted by Kea
default-lease-time 1800;

# use substring in a reductible match
class "reductible" {
    match concat("domain=", suffix(option host-name, 3));
}

subclass "reductible" "domain=com" { }

# reduce literals too
class "literal" {
    match if option host-name = concat("www.", "example.", "com");
}

# raw
option host-name = concat("www.", option domain-name);