[PATCH] Extensions for SRFI-171 (Transducers)

[Colin Woodbury]

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

0001-srfi-171-add-twindow-and-various-reducers.patch
Description: Text Data

0002-doc-add-new-SRFI-171-reducers-to-the-manual.patch
Description: Text Data

0003-srfi-171-add-unit-tests-for-new-functions.patch
Description: Text Data