On Tue, Feb 20, 2018 at 8:22 AM, Gershom B wrote:

From: Joachim Breitner

...

But on the other hand, pointfree.io tells me that you can write

trace =<< f trace =<< show . f

so I'm not sure how urgent these are.

Nifty! If we add this prominently to the docs in Data.Trace, wouldn’t that suit us better?

If I’m not mistaken, those make use of the unwrapped reader monad? In my opinion, that is an instance that is confusing and unidiomatic to many people. I don’t think that “easy to write with unwrapped reader” is the same as “easy to write” (or “easy to understand”). I wouldn’t want core docs to recommend this as an approach.

-g

I agree with Gershom. Michael