New tailRecM laws + Bug fixes 🐞

bow-swift / bow

🏹 Bow is a cross-platform library for Typed Functional Programming in Swift

https://bow-swift.io

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Closed ferranpujolcamins closed 3 years ago

ferranpujolcamins commented 3 years ago

I added two new laws to test tailRecM (I took them from Scala).

With the new tailRecMConsistentFlatMap law I discovered and fixed bugs in the implementation of tailRecM for Ior and WriterT.

In Ior, when flatMapping on a Both value, when the new value is Right, we were returning Both (correct value is Right).
In WriterT we were not combining the old W with the new W obtained after flatmapping.

truizlop commented 3 years ago

Awesome! Good catch!