4c64c13 · servant · git.iko.soy

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Add EmptyAPIClient and `instance HasClient EmptyAPI`

4c64c13David Turner9 years ago

doc/tutorial/Client.lhs+4−1

compare with master

unifiedsplit

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

62type API = "position" :> Capture "x" Int :> Capture "y" Int :> Get '[JSON] Position

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

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

65+ :<|> EmptyAPI

65```

66```

67What we are going to get with **servant-client** here is three functions, one to query each endpoint:

68What 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"

77marketing :: ClientInfo -- ^ value for the request body

78marketing :: ClientInfo -- ^ value for the request body

78 -> ClientM Email

79 -> ClientM Email

80+

81+emptyClient :: EmptyAPIClient

79```

82```

81Each function makes available as an argument any value that the response may

84Each function makes available as an argument any value that the response may

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

88api :: Proxy API

91api :: Proxy API

89api = Proxy

92api = Proxy

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

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

92```

95```

94`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.

97`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

24 , ClientEnv (ClientEnv)

25 , mkAuthenticateReq

26 , ServantError(..)

27+ , EmptyAPIClient(..)

27 , module Servant.Common.BaseUrl

28 , module Servant.Common.BaseUrl

28 ) where

29 ) where

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

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

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

89 clientWithRoute (Proxy :: Proxy b) req

90 clientWithRoute (Proxy :: Proxy b) req

92+-- | TODO docs

93+data EmptyAPIClient = EmptyAPIClient

94+

95+instance HasClient EmptyAPI where

96+ type Client EmptyAPI = EmptyAPIClient

97+ clientWithRoute Proxy _ = EmptyAPIClient

98+

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

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

92-- the corresponding querying function will automatically take

100-- the corresponding querying function will automatically take

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

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