Hello everyone,

I've written a long review of the status quo regarding named (keyword) and optional parameters in various Schemes which I've now published online. It includes proposals for things we can do right now to get keyword arguments interoperably and/or portably, albeit less than satisfactory in some cases, pending further input. (I had hoped to release it as a SRFI and eventually produce a final version, but it’s not a solid enough library proposal for a SRFI yet.) You can read the review at <https://dpk.gitlab.io/presrfis/arguments.html>.

The goal is ultimately that someone (me or someone else) can take the results of this review and make a solid SRFI proposal, with sample implementation and test suite and so on, for how we can move forward R7RS-wise on this vexed question, so I think this is relevant for this mailing list. All feedback is welcome, especially from the maintainers of Scheme implementations on how they might be willing to help make the proposals here less compromised if they can be moved forward to something more solid.

One thing I'm already aware of: in the conclusion, I mention that it would be nice to have compiler macros in Scheme; at the time, I was unaware that R6RS Schemes effectively have them through the ability to have syntax patterns match an identifier out of first-position context, and that this is on the ballot for R7RS as part of syntax-case. One thing I'd like to know, not only in this context, is what (potential) implementers of R7 think of this: Do you think you could implement it?

Other plans for future revisions: I'd also like to consider alternative approaches to supporting Racket and Kawa, and give better attention to the possibility of just using symbols for keyword names than I currently do.

Many thanks,

Daphne Preston-Kendal