re: tail recursion

[Dick Gabriel <RPG@SAIL.Stanford.EDU>]

[In reply to message from gls@think.com sent Tue, 24 Apr 90 16:50:50 EDT.]

I guess I'm one of the rare people who wants to remove a requirement for
tail call removal. I also favor removing a requirement on a garbage
collector.

I favor including some remarks in the form of advice to implementors that
states that people who use Scheme will write programs that depend on
certain resource usage contraints, where tail call removal and garbage
collection are discussed, and that it is expected that such programs will
work a particular way.  The phrasing in this section should be quite
strong, possibly even defining levels of implementation conformance, but
it should stop short of a hard implementation requirement.

But I want it to be allowed to call an implementation a `Scheme' even if I
am able only to run programs with certain restrictions.

Let me repeat my reason: I feel it is vitally important to get Scheme into
the mainstream, and it is better to place as few limitations on that
process as possible, at least for now. Tail call removal is possibly a
large barrier to certain compiler groups who would otherwise support
Scheme completely.  At least at present.

Maybe the people on this list would not want to use that Scheme, but do
those people insist on the right to prevent people from calling that
implementation Scheme? And is that principle worth giving up inroads to
the mainstream?

			-rpg-