Custom types in API

[ip1981]

I could not find anything related, except maybe the #766.

So here is what I'd like to have (at least for the client):

data MyType = Foo Int | Bar String | Zzzz Int Int
-- and the URLs like "/example?foo=1" or "/example?bar=qwerty" or "/example?z1=1&z2=2"
type API = "example" :> MyType :> Get '[ JSON] Int
...

clientFunction :: MyType ->  ClientM Int
...

What classes/types families should I implement?

[ericnething]

You'll want to define instances for ToHttpApiData and FromHttpApiData. https://hackage.haskell.org/package/servant-0.17/docs/Servant-API.html#t:ToHttpApiData

[dmjio]

@ip1981 you'll need to implement HasClient api => HasClient (MyType :> api), you can most likely copy the existing code for QueryParam and modify it slightly for your data type. See https://github.com/haskell-servant/servant/blob/master/servant-client-core/src/Servant/Client/Core/HasClient.hs#L432

[ip1981]

Yes, that was it. For future references, there is similar question: #884

And my solution: ip1981/openweathermap@27b2970