https://github.com/foxhound-systems/eved

Eved is an API definition eDSL in the spirit of Servant
https://github.com/foxhound-systems/eved

haskell

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Eved is an API definition eDSL in the spirit of Servant

• Host: GitHub
• URL: https://github.com/foxhound-systems/eved
• Owner: foxhound-systems
• License: bsd-3-clause
• Created: 2021-04-06T15:30:07.000Z (over 3 years ago)
• Default Branch: master
• Last Pushed: 2021-10-25T22:05:19.000Z (about 3 years ago)
• Last Synced: 2024-08-10T10:11:53.878Z (3 months ago)
• Topics: haskell
• Language: Haskell
• Homepage: https://hackage.haskell.org/package/eved
• Size: 68.4 KB
• Stars: 8
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Eved - A Value Level Servant Replacement

Eved is an API definition eDSL in the spirit of [Servant](https://hackage.haskell.org/package/servant). 

The main difference from Servant is that Eved is a value level API, whereas Servant relies very heavily on fancy type level programming. 

Eved is highly extensible (both in terms of implementations and new terms) thanks to its utilization of the so called `final tagless` encoding.

## Example

### Api Definition

```haskell

import           Data.Text              (Text)

import           Web.Eved

import qualified Web.Eved.ContentType   as CT

import qualified Web.Eved.QueryParam    as QP

import qualified Web.Eved.UrlElement    as UE

type Api m =

       (Integer -> Integer -> m Integer)

  :<|> (Text    -> Integer -> m Integer)

  :<|> (Text    -> Integer -> m Integer)

api :: Eved api m => api (Api m)

api =

      (lit "v1" .> capture "captureNum" UE.integer .> queryParam "arg1" QP.integer .> get [CT.json @Integer])

 .<|> (lit "v1" .> capture "captureText" UE.text .> reqBody [CT.json @Integer] .> post [CT.json @Integer])

 .<|> (lit "v2" .> capture "captureText" UE.text .> queryParam "arg1" QP.integer .> get [CT.json @Integer])

```

### Client

```haskell

import           Web.Eved.Client

v1CaptureNum :<|> v1CaptureText :<|> v2CaptureText = getClient api "http://localhost:3000"

```

### Server

```haskell

import           Control.Monad.IO.Class

import           Control.Monad.Reader

import           Web.Eved.Server

import           Network.Wai.Handler.Warp

serve :: IO ()

serve = run 3000 $ server (`runReaderT` (Env 100)) handlers api

data Env = Env

    { envSecret :: Integer

    }

handlers :: (MonadIO m, MonadReader Env m) => Api m

handlers =   (\a b -> pure $ a + b)

        :<|> (\_ i -> fmap ((+) i) (asks envSecret))

        :<|> (\_ i -> pure i)

```

## Prior Art

TODO

## How to extend the language

TODO