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A comment on Functional calisthenics. Parent comment

Re:Functional calisthenics by danidiaz on Thursday October 19, 2017 @03:51PM (#15511034)
Here is an answer in the CS Theory Stack Exchange that explains how: https://cstheory.stackexchange.com/a/18399/13730 (I'm not endorsing it as a practical way of doing it, mind you.)

The idea is that the only explicit recursion is contained in generic combinators "fold_result" and "unfold_result" that are "boring" in the sense that they can be derived mechanically from the "resultF" data type and do not actually know about the binary search; they just do recursion.

In practice, folds and unfolds tend to be more useful for other things.

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Re:Functional calisthenics by MiyamotoAkira on Thursday October 19, 2017 @04:17PM (#15511206)
In fact, a colleague that is reading SICP at the moment is the one that basically put the idea forward, as he was going through the whole idea of fold/map/unfold on the book exercises
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