Happy holidays everyone, I hope everything is going well for you.

Since discovering SRFI-171 (Transducers) I have fallen in love with it. 
Transducers let me "talk the way I want to talk" while knowing that I'm 
being efficient underneath w.r.t. to iteration and allocation. In using 
Guile's implementation, I noticed a few common idioms missing that are 
otherwise present in other languages, so I've added them in a series of 
patches. I've been using these often for a number of weeks without 
issue, but of course have added unit tests as well.

The full details are in the commit messages, but here are the main 
highlights:

  * rfold: The fundamental reducer. This allows the user to turn any
    two-arg function into a valid reducer, so that they don't need to
    worry about hand-writing reducers via case-lambda.
  * rfind: Yields the first item in the transduction that matches some
    predicate. Nice for locating some specific value from a potentially
    large data source (e.g. a port).
  * twindow: Like tsegment, but yields overlapping slices into the data.

Cheers, and have a great holiday.

Colin