But it's a Rosetta Stone fire-and-forget demo script and I doubt we'd see any other function added.

True, but I write Rosetta code snippets to give me insights into real world production code ... so though the examples may be small, I pretend they're serious real-world production code, so as to gain clearer insights into language features.

Thanks for the tip about Readonly ... which I confess I've never used. Found this good-looking link CPAN modules for defining constants by Neil Bowers (neilb) ... which just made me pine for the simplicity of C++ built-in const keyword. :)