feat: add Gen.option

[favonia]

Close #226.

[jmid]

LGTM!

• good point about naming consistency across Gen and Print
• I also appreciated that you added it for both QCheck.Gen and QCheck2.Gen

Should we update the deriver to use option while we are at it? @vch9

qcheck/src/ppx_deriving_qcheck/QCheck_generators.ml

Line 28 in be9a0e7

let option ~loc e = [%expr QCheck.Gen.opt [%e e]]

[jmid]

Thanks for the update!

The CI is failing the tests. @vch9 wrote a bunch of good tests to ensure that the ppx produces the expected output.
These also need updating. You can run the tests locally with make test to catch such things early.

[vch9]

Maybe we can begin the "deprecated" cycle here?

[vch9]

Looks fine to me as well. I'd be in favor of deprecating the opt in favor of option.

[favonia]

I'm slightly worried that deprecating Gen.opt now would force people to change code with few benefits. Currently, dune by default would treat warnings as errors, which means CI or testing might suddenly fail due to the warning. I feel the deprecation cycle could begin after lots of function names have been changed due to #162 and other related issues, but not for just Gen.opt. That said, I'm happy to make the change if most people think it's worth it.

[vch9]

I'm slightly worried that deprecating Gen.opt now would force people to change code with few benefits. Currently, dune by default would treat warnings as errors, which means CI or testing might suddenly fail due to the warning. I feel the deprecation cycle could begin after lots of function names have been changed due to #162 and other related issues, but not for just Gen.opt. That said, I'm happy to make the change if most people think it's worth it.

I think the next release will (or should) include #223 which would introduce this deprecation cycle anyway. But as I'm not done with this PR the maintainers may publish a release without it, I could deprecate opt in #223 afterward, and then, leave your PR as is.

[jmid]

Thanks for this - and sorry for the delay. Merging...