regexp_param.pp

$regexp = /^.$/
notice(type($regexp))

class foo($bar) {
  notice(type($bar))
}

class { 'foo': bar => $regexp }

out

Notice: Scope(Class[main]): Regexp[/^.$/]
Notice: Scope(Class[Foo]): String

Hah. It gets worse:

$regexp = /^.$/
notice(type($regexp))

class foo($bar) {
    $buz = Regexp[$bar]
    notice(type($bar))
    notice(type($buz))
}

class { 'foo': bar => $regexp }

root@master:~ # puppet apply test.pp
Notice: Scope(Class[main]): Regexp[/^.$/]
Notice: Scope(Class[Foo]): String
Notice: Scope(Class[Foo]): Type[Regexp[/\/^.$\//]]
Notice: Compiled catalog for master.puppetlabs.vm in environment production in 0.10 seconds
Notice: Applied catalog in 0.31 seconds