Usage (No Constructor imported)

[MohsenNz]

Hello there. I configured my project for using grpc-haskell (in cabal, not nix). But after I tried to use example arithmetic (I copied the files and directory to my own project) I encountered these errors: It say it needed type constructor Arithmetic. After I import that, I encountered: It says Arithmetic constructor is not exported. Then I checked the generated file Arithmetic.hs: Here there is no data exported. I'm wondering how to use it ?

[MohsenNz]

OK, it was my mistake. I wasn't in my development shell (nix develop, some dependencies like grpc-c were defined here). After entering that the problem solved. Anyway, I still had a question how Arithmetic constructor and other stuff are importable will they are not exported in Arithmetic.hs ? (I'm newbie in Haskell and will thankful for putting up with me)

[ixmatus]

@MohsenNz if there are no explicit exports from a module, then everything is exported, which is the case with module Arithmetic where. The haskell.org website has what looks like a good tutorial on modules: https://www.haskell.org/tutorial/modules.html and I recommend reading that.

If you are new to Haskell, I recommend starting your learning journey with something simpler that has better tutorial materials for beginners like Servant for web applications.