Scheme Request for Implementation 157,
"Continuation marks,"
by Marc Nieper-Wißkirchen,
has gone into "final" status.

The document and an archive of the discussion are available
at <https://srfi.schemers.org/srfi-157/>.

Here's the abstract:

  Continuation marks are a programming language feature that
  allows one to attach information to and retrieve
  information from continuations, generalizing stack
  inspection.  Conceptually, a continuation consists of a
  number of frames where each frame stands for an active
  procedure call that is not a tail call.  A continuation
  mark is then a key-value pair associated with a frame,
  with keys compared using eq?.  At most one mark for a
  given key can be attached to a single frame.

  Besides stack inspection, continuation marks can be used
  to implement dynamic scope, delimited continuations, or
  delayed evaluation that is able to handle iterative lazy
  algorithms.

  This SRFI proposes to add continuation marks to the Scheme
  programming language.  The interface defined here is
  modelled after Racket's continuation marks.  It does not
  include all forms and procedures provided by Racket but
  provides a compatible subset.

Regards,

SRFI Editor