[Chapter 12] Traverse is taken out of the blue

[felipegmarques]

In Chapter 12, traverse is presented out of the blue. sequence is explained, but in the section Type Feng Shui, traverse is not explained.

[KtorZ]

You mean, not explained like in "There's a full section about it also giving implementation details" :smile: ?

I believe it's fine on this one :+1: . Maybe it could deserve a small note in brackets like

traverse (detailed in the next section)

Or something like this. Happy to take PRs :smiley:

[felipegmarques]

Sorry for the poor explained issue. 😞 I end up writing it on a hurry.

In section Type Feng Shui, it starts saying: The Traversable interface consists of two glorious functions: sequence and traverse., which creates an expectation that traverse would be explained.

Then in section Effect Assortment, there is an example, a little bit more high-level than the ones presented for sequence in the begin of Type Feng Shui.

When I arrived at this part I did not understand what traverse behaviour was and its motivation. I end up looking for other articles explaining it, specifically this one.

Finally, I understand this issue is a result of my experience reading the book and maybe it was not an issue for other people. In general, the experience reading this book has being very satisfatory and I really appreciate what you guys have done! 😄

[KtorZ]

Going again through reading, it could deserve a small line of introduction indeed. Even before diving into what sequences is.

[sevillaarvin]

I'm having a really hard time understanding traverse. I understand the type signature in that it's like map but it will wrap the values inside the functor instead of wrapping the functor itself, but I still don't understand it well enough to come up with a valid implementation and examples.

Unfortunately the link provided is dead, I will link a webarchive link below for reference:

https://web.archive.org/web/20201023080122/https://sidburn.github.io/blog/2016/04/14/sequence-and-traverse