I tend to prefer using ${\...} for interpolation - so

  print "${\join ',', @array}";

or so. See http://shadowcat.co.uk/blog/matt-s-trout/madness-with-method... for more fun you can have like this.

Oh, and remember - sometimes makefiles that do useful things to and with production code should contain one liners.

Don't assume that the intersection of "one liner" and "production" is zero - when I ran the Web Server Survey at Netcraft about 3/4 of it was one liners driven by make ...