4c64c13 · typeable/servant

git.iko.soy/typeable/servant

Add EmptyAPIClient and `instance HasClient EmptyAPI`

commit4c64c13af0a2300d721a8e4e55d9652fc4d97e11 authorDavid Turner <dave.c.turner@gmail.com> dateTue 16 May 2017, 09:42 (9 years ago) parent94483d5

2 files changed+12−1

compare with master

unifiedsplit

doc/tutorial/Client.lhs+4−1 servant-client/src/Servant/Client.hs+8

doc/tutorial/Client.lhs+4−1

@@ -62,6 +62,7 @@ Enough chitchat, let's see an example. Consider the following API type from the

6262type API = "position" :> Capture "x" Int :> Capture "y" Int :> Get '[JSON] Position

6363 :<|> "hello" :> QueryParam "name" String :> Get '[JSON] HelloMessage

6464 :<|> "marketing" :> ReqBody '[JSON] ClientInfo :> Post '[JSON] Email

65+ :<|> EmptyAPI

6566```

6667

6768What we are going to get with **servant-client** here is three functions, one to query each endpoint:

@@ -76,6 +77,8 @@ hello :: Maybe String -- ^ an optional value for "name"

7677

7778marketing :: ClientInfo -- ^ value for the request body

7879 -> ClientM Email

80+

81+emptyClient :: EmptyAPIClient

7982```

8083

8184Each function makes available as an argument any value that the response may

@@ -88,7 +91,7 @@ the function `client`. It takes one argument:

8891api :: Proxy API

8992api = Proxy

9093

91−position :<|> hello :<|> marketing = client api

94+position :<|> hello :<|> marketing :<|> emptyClient = client api

9295```

9396

9497`client api` returns client functions for our _entire_ API, combined with `:<|>`, which we can pattern match on as above. You could say `client` "calculates" the correct type and number of client functions for the API type it is given (via a `Proxy`), as well as their implementations.

servant-client/src/Servant/Client.hs+8

@@ -24,6 +24,7 @@ module Servant.Client

2424 , ClientEnv (ClientEnv)

2525 , mkAuthenticateReq

2626 , ServantError(..)

27+ , EmptyAPIClient(..)

2728 , module Servant.Common.BaseUrl

2829 ) where

2930

@@ -88,6 +89,13 @@ instance (HasClient a, HasClient b) => HasClient (a :<|> b) where

8889 clientWithRoute (Proxy :: Proxy a) req :<|>

8990 clientWithRoute (Proxy :: Proxy b) req

9091

92+-- | TODO docs

93+data EmptyAPIClient = EmptyAPIClient

94+

95+instance HasClient EmptyAPI where

96+ type Client EmptyAPI = EmptyAPIClient

97+ clientWithRoute Proxy _ = EmptyAPIClient

98+

9199-- | If you use a 'Capture' in one of your endpoints in your API,

92100-- the corresponding querying function will automatically take

93101-- an additional argument of the type specified by your 'Capture'.