[pg]

I don't expect implementations to be compliant. Starting with an initial phase where you care just about the concepts and not at all about efficient implementation almost guarantees you're going to have to discard some things from that phase when you make a version to run on the computers of your time. But I think it's still a good exercise to start out by asking "what would I do if I didn't count the cost?" before switching to counting the cost, instead of doing everything in one phase and having your thinking constrained by worries about efficiency.

So cleverness in implementation won't translate into compliance, but rather into inventing declarations that programmers can use that will make their programs dramatically faster. E.g. if programmers are willing to declare that they're not going to look inside or modify literals, you don't have to actually represent functions as lists. And maybe into making really good programming tools.

As I said elsewhere, half jokingly but also seriously, this language is going to give implementors lots of opportunities for discovering new optimization techniques.