The codedumper program parses the JS code passed to its STDIN (using the new experimental version), calls set_global(undef), and then dumps it, followed by a Deparse of the Perl code generated. It’s use- ful for debugging, but you can use it for fun as well. Try running this through it: a:for(;;)b:for(;;)c:do d:try{}finally{}while(true) You’ll need Data::Dump::Streamer installed, along with the DDS alias.