Add servant 0.19 support to servant-util

[marinelli]

This PR proposes to:

• Add support to build with servant >= v0.19 (fix Build problem with servant 0.19 #38)
• Add cabal.project file
• Fix building with universum-1.7.3

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[treeowl]

This seems really awkward. How bad would it be to bump the dependency version?

[marinelli]

I do not like this solution too. If supporting servant 0.18 is not required, let's remove it.
Btw, I'll create an other PR to export encodeQueryParam from the servant-client-core package.
Since this haskell-servant/servant#1549, it would not be required anymore to add the encodeQueryParam function, it might be used the encodeQueryParamValue function.

[marinelli]

Did you were thinking something like this marinelli@a0dbeeb?

[marinelli]

@Martoon-00 what do you think about it?

[Martoon-00]

I apologize for the late reply 🙏 🙏

I don't like such tricks with CPP pragmas too, but in this case its scope is sufficiently limited and it seems like the least evil to me.

Let's go with the current solution to leave others some time if they need a recent feature of servant-util but cannot afford to switch to the servant-0.19. And after a couple of major releases of servant, or if this CPP turns out to hinder other features, we will strip the old behaviour.

I also asked our OPS team to make CI run both the old and new versions of servant-client-core (internal ticket for this).

---

@marinelli You are also very welcome to start using haskell-servant/servant#1549 here as soon as it appears in a release. Just leave a note in the changelog that we do not support servant-0.19, rather only < 0.19 and >= 0.19.X.

Thanks a lot for your work!

[marinelli]

I'm not sure anymore that re-exporting encodeQueryParamValue from servant-client-core is a good idea :)
We'll see.

[Martoon-00]

I apologize for the late reply 🙏 🙏

I don't like such tricks with CPP pragmas too, but in this case its scope is sufficiently limited and it seems like the least evil to me.

Let's go with the current solution to leave others some time if they need a recent feature of servant-util but cannot afford to switch to the servant-0.19. And after a couple of major releases of servant, or if this CPP turns out to hinder other features, we will strip the old behaviour.

I also asked our OPS team to make CI run both the old and new versions of servant-client-core (internal ticket for this).

---

@marinelli You are also very welcome to start using haskell-servant/servant#1549 here as soon as it appears in a release. Just leave a note in the changelog that we do not support servant-0.19, rather only < 0.19 and >= 0.19.X.

Thanks a lot for your work!

[Martoon-00]

Again thank you for the update.

Please rebase and let's merge it.

[marinelli]

Again thank you for the update.

Please rebase and let's merge it.

I rebased and updated the servant-util/CHANGES.md file.