Perhaps move Lens functions to a separate package? about xlsx

[danchoi]

I removed the dependency on lens in a fork: https://github.com/danchoi/xlsx

I had to remove the tests and the example temporarily. But the lens-free fork I just made does build.

[qrilka]

Do you have any other examples? aeson and aeson-lens don't look as a good example as those are 2 separate packages developed by different authors (with a dependency one on another of course)
In any case that would be breaking change requiring upping version to 0.2

[danchoi]

• lens-text-encoding
• lens-time
• lens-datetime
• lens-properties

?

[danchoi]

Also here's an argument for avoiding propagating the dependency on lens if possible:

http://fvisser.nl/post/2013/okt/11/why-i-dont-like-the-lens-library.html

[qrilka]

None of them seem to give an example of a package and lens API developed at least at the same time.
Counterexamples exist also - e.g. http://hackage.haskell.org/package/thyme
I know arguments against dependency on lenses and have read that blog post also.
Just wanted to know of an example package which was developed taking into account lenses API (though in a separate package)

[danchoi]

To be honest, I don't know of any examples that meet that requirement. I guess my argument stands or falls on how convincing that philosophy expressed in that blog post is. If you're not convinced, I'm fine using my fork for our own private purposes. Thank you very much writing it!

[qrilka]

I see the arguments but I'm not convinced (at least yet).
Main argument against I see at the moment is that docs/examples (though there are not so much of them) use lenses API and we would need either have them duplicated (with API changed) or put them only into xlsx-lenses package which seem to be a bit awkward.
Another counterexample is http://hackage.haskell.org/package/wreq which uses lenses to bring "ease of use" to the library (though xlsx is not yet good from this POV)

[danchoi]

I found something. On this issue thread, they dropped lens and substituted something more lightweight, and let users import the big Lens library if they needed more.

VinylRecords/Vinyl#22

[qrilka]

I have found twitter-types/twitter-types-lens package pair but you link looks much more interesting.
Do you want to create a PR for such a change?

[danchoi]

Do you want to create two packages in the main repo like twitter-types or try what VinylRecords did? If the latter, I'll need some time to study what they did.

[qrilka]

The latter seems to be more elegant - see my question in that thread, probably we could get some help :)
And there is no rush in implementing the solution (at least for me)

[danchoi]

OK cool.

[qrilka]

@danchoi do you still want this to be done? Almost a year passed already and for myself I don't see much motivation to remove lens dependency. Please raise your voice - otherwise I'll close this issue tomorrow

[danchoi]

Go ahead an close. I don't think I have time either, but I'll let you know if I manage to do it. Thank you for writing the library.