Puppet

It would be nice if one could give an array to regsubst(), and make it perform the substitution on each element of that array.

One, perhaps non-obvious, use case is to have a definition that takes an array as parameter, and have it “loop” over that by giving it as the name parameter to a helper definition, like this:

    define my_define($param, ...)
    {
    $x = regsubst($param, ".*", "$name//\\&")
    my_define_helper {
        $x: ...;
    }
    ...
    }

    define my_define_helper(...)
    {
    $n = regsubst($name, '^(.*)//(.*)$', '\1')
    $p = regsubst($name, '^(.*)//(.*)$', '\2')
    # Do things with $n and $p, which now are the $name and one
    # element of $param from my_define, respectively.
    }

    my_define {
    "foo": param => ["a", "b", "c"], ...;
    "bar": param => ["a", "b", "c"], ...;
    }

One can already do the looping today, but only as long as the param parameters to My_define[foo] and My_define[bar] doesn’t have any elements in common. (This use case came up in puppet-users recently, where the poster wanted a definition for managing PGP keystores, where one parameter would be an array of keys. http://groups.google.com/group/puppet-users/browse_thread/thread/d3e85f7869f66ed1)