Hello everyone,

I’ve just published the fourth revision to this document.
<https://dpk.gitlab.io/presrfis/arguments.html>

This is a fairly major update; here’s a summary:
• Note in the introduction some of the differences between existing Schemes’ keyword systems, plus some other portable (in a broad sense of the term) solutions, including syntax-keywords and Common Scheme.
• Major revision of the section on keyword datums, renamed to ‘Keyword representation in expressions’. The new version considers the properties of different keyword representations in more faceted detail than previously.
• Note that the DSSSL/SRFI 88 and Common Lisp/Emacs Lisp/Clojure lexical notations for keyword datums are incompatible with R7RS small.
• Replace section on the minimally compatible proposal for optional positional arguments with a reference to SRFI 227, which standardizes what had previously been proposed there.
• Note the benefits for optimization of restricting the dynamism of lexical keyword appearances.
• Fill in acknowledgements for feedback up to this revision.

Word- and line-based diffs from the previous published version to this one can be seen at
<http://dpk.io/temp/3-to-4-word>
<http://dpk.io/temp/3-to-4-line>

Daphne