I've just published draft #4 of SRFI 189. It was submitted by John Cowan, co-author of the SRFI.
Here are John's comments on the draft:
Note that I am waiting to announce last call until the implementation and tests are complete.
I think this is ready for last call now. Wolfgang's implementation will catch up shortly.
Here is the commit summary:
- fold functions accept all values plus nil
- Implement Draft #3 of SRFI 189 (multiple values).
- Remove maybe-contains? and either-contains?.
- clarified -sequence operations
- maybe->list mutation is an error
- Update -sequence functions.
- Remove tests for -contains procedures.
- Update test sets: predicates, accessors, join and bind.
- Delete "obj" argument in either-remove and -filter.
- Update test sets: sequence operations, conversions.
- Fix arity error in either->lisp-values.
- Update test set for map, fold, unfold.
- Return unspecified value from -for-each procedures.
- Fix typos in definition of maybe-if.
- Improve the bargain basement SRFI 78 implementation.
- Comment cleanup and improvement.
- Add tests for `maybe-if'.
- Refactor some tests for readability.
- style typos
- Lefts now contain exactly one value
- Show keywords.
- Use HTML links on HTML pages.
- Fix typo. Publish fourth draft.
Here's the diff: