I've just published draft #5 of SRFI 146.  It was submitted
by Marc Nieper-Wißkirchen, the author of the SRFI.

  <http://srfi.schemers.org/srfi-146/>

Here's the diff:

  <https://github.com/scheme-requests-for-implementation/srfi-146/pull/4>

Here are Marc's comments on the new draft:

  The main change is the addition of an implementation of
  SRFI 113 ("sets and bags") in terms of the mappings of
  SRFI 146.  This is to demonstrate the usability of the
  interface of SRFI 146, to have an implementation of SRFI
  113 based on comparators with ordering instead of hash
  procedures, and to have the base for an implementation for
  ordered sets and bags for a future SRFI.

  Other changes include some code fixes in the SRFI 146
  code, and adding the requirement to invoking the failure
  and success procedures in tail context when viable.

  Commit Summary

  * code fixes; added implementation for SRFI 113
  * add note about included SRFI 113 implementation
  * map-find and map-ref should tail-call failure and success
  * Merge branch 'master' of https://github.com/scheme-requests-for-implementation/srfi-146

  File Changes

  * M nieper/rbtree.scm (6)
  * M srfi-146.html (15)
  * A srfi/113.scm (817)
  * A srfi/113.sld (65)
  * A srfi/113/test.sld (669)
  * M srfi/145.scm (4)
  * M srfi/146.scm (45)
  * M srfi/146/test.sld (3)
  * M tests.scm (4)

Regards,

SRFI Editor