Document differences vs proto-lens

[robinp]

Would be nice to know the difference vs https://hackage.haskell.org/package/proto-lens.
+@judah

[Gabriella439]

My understanding is that the high-level differences between proto-lens and proto3-suite are:

• proto-lens is works as a protoc plugin and proto3-suite does not

  The proto-lens-protoc package provides a proto-lens-protoc executable that you can pass as a protoc plugin, whereas proto3-suite provides a compile-proto-file standalone executable

  We consider this a mistake in the design of proto3-suite and we think that it should be fixed to also work as a protoc plugin

• proto3-suite provides gRPC support and proto-lens does not

  This is powered by the gRPC-haskell library, which is a Haskell binding to the C library for grpc

  We also think that this should change in the long run. When we authored gRPC-haskell there was not yet an HTTP2 client package available, which is why we resorted to reusing the C library. Now that there is the http2-client package we think a Haskell-native implementation of gRPC is the better approach (mainly for improved concurrency performance and reliability)

• proto-lens is on Hackage and proto3-suite is not

  The main reason that proto3-suite is not on Hackage is because of our reservations about the
  above two issues

  That means that there are other Hackage libraries that build on top of proto-lens, which you can find here:

  http://packdeps.haskellers.com/reverse/proto-lens

There are also differences in the API that each library presents, but I think the above three differences are key reasons that drive people to adopt one package over the other