Servant Reason
<img src="https://cdn.svgporn.com/logos/reasonml.svg" alt="reason" height="20"/>
<img src="https://www.haskell.org/img/haskell-logo.svg" alt="reason" height="20"/>
Automatically derive bindings for Servant APIs in Reason. Originally build by
converting servant-elm to
Reason. Types are generated using
reason-export.
More docs on Hackage.
A full example of how to integrate Servant and Reason is available at
servant-reason-example.
Usage
Run the tests if you want a concrete example. They will build a _test-cache
directory that contains a sample Reason repository for a servant API. test also
contain example output files for different kinds of bindings.
Usage is simple and automatic. If you have an API like the one below
{-# LANGUAGE DataKinds #-}
{-# LANGUAGE DeriveGeneric #-}
{-# LANGUAGE OverloadedStrings #-}
{-# LANGUAGE TypeOperators #-}
import Reason (Spec (Spec), specsToDir, toReasonDecoderSource,
toReasonTypeSource)
import GHC.Generics (Generic)
import Servant.API ((:>), Capture, Get, JSON)
import Servant.Reason (ReasonType, Proxy (Proxy), defReasonImports,
generateReasonForAPI)
data Book = Book
{ name :: String
} deriving (Generic)
instance ReasonType Book
type BooksApi = "books" :> Capture "bookId" Int :> Get '[JSON] Book
You can expose your API to reason with:
module Main where
import Data.Proxy
import Reason
import Data.Text hiding (intercalate, map)
import Db
main :: IO ()
main = do
let code = defReasonImports
: toReasonTypeSource (Proxy :: Proxy Book)
: toReasonDecoderSource (Proxy :: Proxy Book)
: generateReasonForAPI (Proxy :: Proxy BooksApi))
writeFile "Api.re" $ intercalate "\n\n" $ map unpack code
That's it. You can now include Api.re
in a Reason project.
Reason setup
The generated code needs access to two Reason libraries
@glennsl/bs-json and
bs-fetch. Get the latest
install instructions from the upstream repos, but at the time of writing these
were:
npm install --save @glennsl/bs-json
npm install --save bs-fetch
Then add @glennsl/bs-json
and bs-fetch
to bs-dependencies
in your bsconfig.json
:
{
...
"bs-dependencies": ["@glennsl/bs-json", "bs-fetch"]
}