Merge pull request #196 from haskell-servant/jkarni/contributing

'Contributing' section in the README + stylish haskell changes

.stylish-haskell.yaml

@@ -0,0 +1,77 @@
+# stylish-haskell configuration file
+# ==================================
+
+# The stylish-haskell tool is mainly configured by specifying steps. These steps
+# are a list, so they have an order, and one specific step may appear more than
+# once (if needed). Each file is processed by these steps in the given order.
+steps:
+  # Convert some ASCII sequences to their Unicode equivalents. This is disabled
+  # by default.
+  # - unicode_syntax:
+  #     # In order to make this work, we also need to insert the UnicodeSyntax
+  #     # language pragma. If this flag is set to true, we insert it when it's
+  #     # not already present. You may want to disable it if you configure
+  #     # language extensions using some other method than pragmas. Default:
+  #     # true.
+  #     add_language_pragma: true
+
+  # Import cleanup
+  - imports:
+      # There are different ways we can align names and lists.
+      #
+      # - global: Align the import names and import list throughout the entire
+      #   file.
+      #
+      # - file: Like global, but don't add padding when there are no qualified
+      #   imports in the file.
+      #
+      # - group: Only align the imports per group (a group is formed by adjacent
+      #   import lines).
+      #
+      # - none: Do not perform any alignment.
+      #
+      # Default: global.
+      align: global
+
+  # Language pragmas
+  - language_pragmas:
+      # We can generate different styles of language pragma lists.
+      #
+      # - vertical: Vertical-spaced language pragmas, one per line.
+      #
+      # - compact: A more compact style.
+      #
+      # - compact_line: Similar to compact, but wrap each line with
+      #   `{-#LANGUAGE #-}'.
+      #
+      # Default: vertical.
+      style: vertical
+
+      # stylish-haskell can detect redundancy of some language pragmas. If this
+      # is set to true, it will remove those redundant pragmas. Default: true.
+      remove_redundant: true
+
+  # Align the types in record declarations
+  - records: {}
+
+  # Replace tabs by spaces. This is disabled by default.
+  # - tabs:
+  #     # Number of spaces to use for each tab. Default: 8, as specified by the
+  #     # Haskell report.
+  #     spaces: 8
+
+  # Remove trailing whitespace
+  - trailing_whitespace: {}
+
+# A common setting is the number of columns (parts of) code will be wrapped
+# to. Different steps take this into account. Default: 80.
+columns: 80
+
+# Sometimes, language extensions are specified in a cabal file or from the
+# command line instead of using language pragmas in the file. stylish-haskell
+# needs to be aware of these, so it can parse the file correctly.
+#
+# No language extensions are enabled by default.
+language_extensions:
+    - TemplateHaskell
+    - QuasiQuotes

HLint.hs

@@ -0,0 +1,6 @@
+import "hint" HLint.Default
+
+ignore "Redundant do"
+ignore "Parse error"
+ignore "Use list comprehension"
+ignore "Use liftM"

README.md

@@ -5,17 +5,56 @@
 
 ![servant](https://raw.githubusercontent.com/haskell-servant/servant/master/servant.png)
 
-These libraries provides a family of combinators to define webservices and automatically generate the documentation and client-side querying functions for each endpoint.
+These libraries provides a family of combinators to define webservices and
+automatically generate the documentation and client-side querying functions for
+each endpoint.
 
-In order to minimize the dependencies depending on your needs, we provide these features under different packages.
+In order to minimize the dependencies depending on your needs, we provide these
+features under different packages.
 
 - `servant`, which contains everything you need to *declare* a webservice API.
-- `servant-server`, which lets you *implement* an HTTP server with handlers for each endpoint of an API.
-- `servant-client`, which lets you derive automatically Haskell functions that let you query each endpoint of a `servant` webservice.
+- `servant-server`, which lets you *implement* an HTTP server with handlers for
+each endpoint of an API.
+- `servant-client`, which lets you derive automatically Haskell functions that
+let you query each endpoint of a `servant` webservice.
 - `servant-docs`, which lets you generate API docs for your webservice.
-- `servant-js`, which lets you derive Javascript functions (using vanilla JS ajax requests, angular or jquery) to query your API's endpoints, in the same spirit as `servant-client`.
-- `servant-blaze` and `servant-lucid` provide easy HTML rendering of your data as an `HTML` content-type "combinator".
+- `servant-js`, which lets you derive Javascript functions (using vanilla JS
+ajax requests, angular or jquery) to query your API's endpoints, in the same
+spirit as `servant-client`.
+- `servant-blaze` and `servant-lucid` provide easy HTML rendering of your data
+as an `HTML` content-type "combinator".
 
 ## Tutorial
 
-We have a [tutorial](http://haskell-servant.github.io/tutorial) guide that introduces the core types and features of servant. After this article, you should be able to write your first servant webservices, learning the rest from the haddocks' examples.
+We have a [tutorial](http://haskell-servant.github.io/tutorial) guide that
+introduces the core types and features of servant. After this article, you
+should be able to write your first servant webservices, learning the rest from
+the haddocks' examples.
+
+## Contributing
+
+Contributions are very welcome! To hack on the github version, clone the
+repository. You can use `cabal`:
+
+```shell
+./scripts/start-sandbox.sh # Initialize the sandbox and add-source the packages
+./scripts/test-all.sh      # Run all the tests
+```
+
+`stack`:
+
+```shell
+stack build    # Install and build packages
+stack test     # Run all the tests
+```
+
+Or `nix`:
+```shell
+./scripts/update-nix-files.sh   # Get up-to-date shell.nix files
+```
+
+Though we aren't sticklers for style, the `.stylish-haskel.yaml` and `HLint.hs`
+files in the repository provide a good baseline for consistency.
+
+Please include a description of the changes in your PR in the `CHANGELOG.md` of
+the packages you've changed. And of course, write tests!

servant-client/src/Servant/Common/BaseUrl.hs

@@ -11,7 +11,7 @@ module Servant.Common.BaseUrl (
   , showBaseUrl
 ) where
 
-import Control.Monad.Catch (MonadThrow, throwM, Exception)
+import           Control.Monad.Catch (Exception, MonadThrow, throwM)
 import           Data.List
 import           Data.Typeable
 import           GHC.Generics

servant-client/src/Servant/Common/Req.hs

@@ -99,7 +99,7 @@ setRQBody b t req = req { reqBody = Just (b, t) }
 
 reqToRequest :: (Functor m, MonadThrow m) => Req -> BaseUrl -> m Request
 reqToRequest req (BaseUrl reqScheme reqHost reqPort) =
-    fmap (setheaders . setAccept . setrqb . setQS ) $ parseUrl url
+    setheaders . setAccept . setrqb . setQS <$> parseUrl url
 
   where url = show $ nullURI { uriScheme = case reqScheme of
                                   Http  -> "http:"

servant-client/test/Spec.hs

@@ -1,4 +1,4 @@
-import Servant.ClientSpec (spec, failSpec)
+import           Servant.ClientSpec (failSpec, spec)
 
 main :: IO ()
 main = do

servant-docs/src/Servant/Docs/Internal.hs

@@ -1,5 +1,5 @@
-{-# LANGUAGE ConstraintKinds        #-}
 {-# LANGUAGE CPP                    #-}
+{-# LANGUAGE ConstraintKinds        #-}
 {-# LANGUAGE DataKinds              #-}
 {-# LANGUAGE DeriveGeneric          #-}
 {-# LANGUAGE FlexibleContexts       #-}
@@ -23,6 +23,7 @@ module Servant.Docs.Internal where
 import           Control.Applicative
 #endif
 import           Control.Lens
+import           Data.ByteString.Conversion (ToByteString, toByteString)
 import           Data.ByteString.Lazy.Char8 (ByteString)
 import qualified Data.CaseInsensitive       as CI
 import           Data.Hashable
@@ -32,7 +33,6 @@ import           Data.Maybe
 import           Data.Monoid
 import           Data.Ord                   (comparing)
 import           Data.Proxy
-import           Data.ByteString.Conversion (ToByteString, toByteString)
 import           Data.String.Conversions
 import           Data.Text                  (Text, pack, unpack)
 import           GHC.Exts                   (Constraint)

servant-examples/auth-combinator/auth-combinator.hs

@@ -1,10 +1,10 @@
 {-# LANGUAGE DataKinds           #-}
-{-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE DeriveGeneric       #-}
-{-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE FlexibleInstances   #-}
 {-# LANGUAGE OverloadedStrings   #-}
 {-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeFamilies        #-}
+{-# LANGUAGE TypeOperators       #-}
 import           Data.Aeson
 import           Data.ByteString          (ByteString)
 import           Data.Text                (Text)

servant-examples/hackage/hackage.hs

@@ -1,7 +1,7 @@
 {-# LANGUAGE DataKinds         #-}
 {-# LANGUAGE DeriveGeneric     #-}
-{-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TypeOperators     #-}
 import           Control.Applicative
 import           Control.Monad
 import           Control.Monad.IO.Class

servant-examples/socket-io-chat/socket-io-chat.hs

@@ -1,6 +1,6 @@
 {-# LANGUAGE CPP               #-}
-{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE DataKinds         #-}
+{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE TypeOperators     #-}
 
 
@@ -8,17 +8,17 @@ import Data.Monoid ((<>))
 #if !MIN_VERSION_base(4,8,0)
 import           Control.Applicative      ((<$>))
 #endif
-import Network.Wai
-import Servant
 import           Network.EngineIO.Wai
+import           Network.Wai
 import           Network.Wai.Handler.Warp (run)
+import           Servant
 
 
 import qualified Control.Concurrent.STM   as STM
 import qualified Network.SocketIO         as SocketIO
 
 
-import Chat (eioServer, ServerState (..))
+import           Chat                     (ServerState (..), eioServer)
 
 
 type API = "socket.io" :> Raw

servant-examples/tutorial/T1.hs

@@ -1,6 +1,6 @@
 {-# LANGUAGE DataKinds     #-}
-{-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE TypeFamilies  #-}
 {-# LANGUAGE TypeOperators #-}
 module T1 where
 

servant-examples/tutorial/T10.hs

@@ -1,9 +1,9 @@
 {-# LANGUAGE DataKinds             #-}
+{-# LANGUAGE FlexibleInstances     #-}
+{-# LANGUAGE MultiParamTypeClasses #-}
+{-# LANGUAGE OverloadedStrings     #-}
 {-# LANGUAGE TypeFamilies          #-}
 {-# LANGUAGE TypeOperators         #-}
-{-# LANGUAGE FlexibleInstances #-}
-{-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE MultiParamTypeClasses #-}
 module T10 where
 
 import           Data.ByteString.Lazy    (ByteString)

servant-examples/tutorial/T2.hs

@@ -1,6 +1,6 @@
 {-# LANGUAGE DataKinds     #-}
-{-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE TypeFamilies  #-}
 {-# LANGUAGE TypeOperators #-}
 module T2 where
 

servant-examples/tutorial/T3.hs

@@ -1,6 +1,6 @@
 {-# LANGUAGE DataKinds     #-}
-{-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE DeriveGeneric #-}
+{-# LANGUAGE TypeFamilies  #-}
 {-# LANGUAGE TypeOperators #-}
 module T3 where
 

servant-examples/tutorial/T4.hs

@@ -1,9 +1,9 @@
 {-# LANGUAGE DataKinds         #-}
-{-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE DeriveGeneric     #-}
-{-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TypeFamilies      #-}
+{-# LANGUAGE TypeOperators     #-}
 module T4 where
 
 import           Data.Aeson

servant-examples/tutorial/T5.hs

@@ -1,8 +1,8 @@
 {-# LANGUAGE DataKinds         #-}
-{-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE DeriveGeneric     #-}
-{-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TypeFamilies      #-}
+{-# LANGUAGE TypeOperators     #-}
 module T5 where
 
 import           Control.Monad.IO.Class

servant-examples/tutorial/T9.hs

@@ -1,8 +1,8 @@
 {-# LANGUAGE DataKinds         #-}
-{-# LANGUAGE TypeFamilies #-}
 {-# LANGUAGE DeriveGeneric     #-}
-{-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE TypeFamilies      #-}
+{-# LANGUAGE TypeOperators     #-}
 module T9 where
 
 import           Control.Applicative

servant-examples/tutorial/tutorial.hs

@@ -3,6 +3,7 @@ import Network.Wai.Handler.Warp
 import           System.Environment
 
 import qualified T1
+import qualified T10
 import qualified T2
 import qualified T3
 import qualified T4
@@ -10,7 +11,6 @@ import qualified T5
 import qualified T6
 import qualified T7
 import qualified T9
-import qualified T10
 
 app :: String -> (Application -> IO ()) -> IO ()
 app n f = case n of

servant-js/examples/counter.hs

@@ -1,7 +1,7 @@
 {-# LANGUAGE DataKinds                  #-}
-{-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE DeriveGeneric              #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE TypeOperators              #-}
 
 import           Control.Concurrent.STM
 import           Control.Monad.IO.Class

servant-js/src/Servant/JS.hs

@@ -1,7 +1,7 @@
 {-# LANGUAGE DataKinds         #-}
-{-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE FlexibleContexts  #-}
 {-# LANGUAGE FlexibleInstances #-}
+{-# LANGUAGE TypeOperators     #-}
 -----------------------------------------------------------------------------
 -- |
 -- Module      :  Servant.JS

servant-js/src/Servant/JS/Angular.hs

@@ -1,9 +1,9 @@
 module Servant.JS.Angular where
 
-import Servant.JS.Internal
 import           Control.Lens
 import           Data.List
 import           Data.Monoid
+import           Servant.JS.Internal
 
 -- | Options specific to the angular code generator
 data AngularOptions = AngularOptions

servant-js/src/Servant/JS/Axios.hs

@@ -1,10 +1,10 @@
 module Servant.JS.Axios where
 
-import Servant.JS.Internal
 import           Control.Lens
 import           Data.Char           (toLower)
 import           Data.List
 import           Data.Monoid
+import           Servant.JS.Internal
 
 -- | Axios 'configuration' type
 -- Let you customize the generation using Axios capabilities

servant-js/src/Servant/JS/Internal.hs

@@ -141,8 +141,8 @@ toValidFunctionName (x:xs) = [setFirstChar x] <> filter remainder xs
     setFirstChar c = if firstChar c
         then c
         else '_'
-    firstChar c = (prefixOK c) || (or . map (Set.member c) $ firstLetterOK)
-    remainder c = (prefixOK c) || (or . map (Set.member c) $ remainderOK)
+    firstChar c = prefixOK c || any (Set.member c) firstLetterOK
+    remainder c = prefixOK c || any (Set.member c) remainderOK
     -- Valid prefixes
     prefixOK c = c `elem` ['$','_']
     -- Unicode character sets

servant-js/src/Servant/JS/JQuery.hs

@@ -1,20 +1,20 @@
 module Servant.JS.JQuery where
 
-import Servant.JS.Internal
 import           Control.Lens
 import           Data.List
 import           Data.Monoid
+import           Servant.JS.Internal
 
 -- | Generate javascript functions that use the /jQuery/ library
 --   to make the AJAX calls. Uses 'defCommonGeneratorOptions'
 --   for the generator options.
 jquery :: JavaScriptGenerator
-jquery = concat . map generateJQueryJS
+jquery = concatMap generateJQueryJS
 
 -- | Generate javascript functions that use the /jQuery/ library
 --   to make the AJAX calls. Lets you specify your own 'CommonGeneratorOptions'.
 jqueryWith :: CommonGeneratorOptions -> JavaScriptGenerator
-jqueryWith opts = concat . map (generateJQueryJSWith opts)
+jqueryWith opts = concatMap (generateJQueryJSWith opts)
 
 -- | js codegen using JQuery using default options
 generateJQueryJS :: AjaxReq -> String

servant-js/src/Servant/JS/Vanilla.hs

@@ -1,21 +1,21 @@
 module Servant.JS.Vanilla where
 
-import Servant.JS.Internal
 import           Control.Lens
 import           Data.List
 import           Data.Monoid
+import           Servant.JS.Internal
 
 -- | Generate vanilla javascript functions to make AJAX requests
 --   to your API, using /XMLHttpRequest/. Uses 'defCommonGeneratorOptions'
 --   for the 'CommonGeneratorOptions'.
 vanillaJS :: JavaScriptGenerator
-vanillaJS = concat . map generateVanillaJS
+vanillaJS = concatMap generateVanillaJS
 
 -- | Generate vanilla javascript functions to make AJAX requests
 --   to your API, using /XMLHttpRequest/. Lets you specify your
 --   own options.
 vanillaJSWith :: CommonGeneratorOptions -> JavaScriptGenerator
-vanillaJSWith opts = concat . map (generateVanillaJSWith opts)
+vanillaJSWith opts = concatMap (generateVanillaJSWith opts)
 
 -- | js codegen using XmlHttpRequest using default generation options
 generateVanillaJS :: AjaxReq -> String

servant-js/test/Servant/JSSpec.hs

@@ -14,10 +14,10 @@ import Test.Hspec
 
 import           Servant.API
 import           Servant.JS
-import qualified Servant.JS.Vanilla as JS
-import qualified Servant.JS.JQuery as JQ
 import qualified Servant.JS.Angular           as NG
 import qualified Servant.JS.Axios             as AX
+import qualified Servant.JS.JQuery            as JQ
+import qualified Servant.JS.Vanilla           as JS
 import           Servant.JSSpec.CustomHeaders
 
 type TestAPI = "simple" :> ReqBody '[JSON,FormUrlEncoded] String :> Post '[JSON] Bool
@@ -102,7 +102,7 @@ axiosSpec = describe specLabel $ do
         cookieOpts = AX.defAxiosOptions { AX.xsrfCookieName = Just "MyXSRFcookie" }
         headerOpts = AX.defAxiosOptions { AX.xsrfHeaderName = Just "MyXSRFheader" }
         genJS :: AxiosOptions -> [AjaxReq] -> String
-        genJS opts req = concat $ map (AX.generateAxiosJS opts) req
+        genJS opts req = concatMap (AX.generateAxiosJS opts) req
 
 angularSpec :: TestNames -> Spec
 angularSpec test = describe specLabel $ do
@@ -130,7 +130,7 @@ angularSpec test = describe specLabel $ do
 generateJSSpec :: TestNames -> (AjaxReq -> String) -> Spec
 generateJSSpec n gen = describe specLabel $ do
     it "should generate valid javascript" $ do
-        let s = jsForAPI (Proxy :: Proxy TestAPI) (concat . map gen)
+        let s = jsForAPI (Proxy :: Proxy TestAPI) (concatMap gen)
         parseFromString s `shouldSatisfy` isRight
 
     it "should use non-empty function names" $ do
@@ -167,7 +167,7 @@ generateJSSpec n gen = describe specLabel $ do
         jsText `shouldContain`  (header n "X-WhatsForDinner" $ "\"I would like \" + headerXWhatsForDinner + \" with a cherry on top.\"")
 
     it "can generate the whole javascript code string at once with jsForAPI" $ do
-        let jsStr = jsForAPI (Proxy :: Proxy TestAPI) (concat . map gen)
+        let jsStr = jsForAPI (Proxy :: Proxy TestAPI) (concatMap gen)
         parseFromString jsStr `shouldSatisfy` isRight
     where
         specLabel = "generateJS(" ++ (show n) ++ ")"

servant-mock/example/main.hs

@@ -1,7 +1,7 @@
 {-# LANGUAGE DataKinds                  #-}
-{-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE DeriveGeneric              #-}
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
+{-# LANGUAGE TypeOperators              #-}
 import           Data.Aeson
 import           GHC.Generics
 import           Network.Wai.Handler.Warp

servant-mock/src/Servant/Mock.hs

@@ -1,10 +1,10 @@
 {-# LANGUAGE CPP                 #-}
 {-# LANGUAGE DataKinds           #-}
-{-# LANGUAGE TypeFamilies #-}
-{-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE FlexibleContexts    #-}
 {-# LANGUAGE FlexibleInstances   #-}
 {-# LANGUAGE ScopedTypeVariables #-}
+{-# LANGUAGE TypeFamilies        #-}
+{-# LANGUAGE TypeOperators       #-}
 -- |
 -- Module     : Servant.Mock
 -- Copyright  : 2015 Alp Mestanogullari
@@ -169,7 +169,7 @@ instance HasMock Raw where
     bdy <- genBody
     respond $ responseLBS status200 [] bdy
 
-    where genBody = fmap pack $ generate (vector 100 :: Gen [Char])
+    where genBody = pack <$> generate (vector 100 :: Gen [Char])
 
 mockArbitrary :: (MonadIO m, Arbitrary a) => m a
 mockArbitrary = liftIO (generate arbitrary)

servant-server/example/greet.hs

@@ -1,9 +1,9 @@
 {-# LANGUAGE DataKinds         #-}
+{-# LANGUAGE DeriveGeneric     #-}
+{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE PolyKinds         #-}
 {-# LANGUAGE TypeFamilies      #-}
-{-# LANGUAGE DeriveGeneric #-}
 {-# LANGUAGE TypeOperators     #-}
-{-# LANGUAGE OverloadedStrings #-}
 
 import           Data.Aeson
 import           Data.Monoid

servant-server/src/Servant/Server/Internal.hs

@@ -27,7 +27,7 @@ import           Control.Monad.Trans.Either  (EitherT)
 import qualified Data.ByteString             as B
 import qualified Data.ByteString.Lazy        as BL
 import qualified Data.Map                    as M
-import           Data.Maybe                  (catMaybes, fromMaybe)
+import           Data.Maybe                  (mapMaybe, fromMaybe)
 import           Data.String                 (fromString)
 import           Data.String.Conversions     (cs, (<>), ConvertibleStrings)
 import           Data.Text                   (Text)
@@ -137,9 +137,7 @@ processMethodRouter handleA status method headers request = case handleA of
   Nothing -> failWith UnsupportedMediaType
   Just (contentT, body) -> succeedWith $ responseLBS status hdrs bdy
     where
-      bdy = case allowedMethodHead method request of
-        True -> ""
-        False -> body
+      bdy = if allowedMethodHead method request then "" else body
       hdrs = (hContentType, cs contentT) : (fromMaybe [] headers)
 
 methodRouter :: (AllCTRender ctypes a)
@@ -512,7 +510,7 @@ instance (KnownSymbol sym, FromText a, HasServer sublayout)
         -- named "foo" or "foo[]" and call fromText on the
         -- corresponding values
         parameters = filter looksLikeParam querytext
-        values = catMaybes $ map (convert . snd) parameters
+        values = mapMaybe (convert . snd) parameters
     in  route (Proxy :: Proxy sublayout) (feedTo subserver values)
     where paramname = cs $ symbolVal (Proxy :: Proxy sym)
           looksLikeParam (name, _) = name == paramname || name == (paramname <> "[]")
@@ -625,7 +623,7 @@ instance (KnownSymbol sym, FromText a, HasServer sublayout)
                   -- named "foo" or "foo[]" and call fromText on the
                   -- corresponding values
                   parameters = filter looksLikeParam matrixtext
-                  values = catMaybes $ map (convert . snd) parameters
+                  values = mapMaybe (convert . snd) parameters
               route (Proxy :: Proxy sublayout) (feedTo subserver values)
       _ -> route (Proxy :: Proxy sublayout) (feedTo subserver [])
     where paramname = cs $ symbolVal (Proxy :: Proxy sym)

servant-server/src/Servant/Server/Internal/RoutingApplication.hs

@@ -11,15 +11,16 @@ import           Data.Monoid                 (Monoid, mappend, mempty)
 import           Control.Monad.Trans.Either         (EitherT, runEitherT)
 import qualified Data.ByteString                    as B
 import qualified Data.ByteString.Lazy               as BL
-import           Data.IORef                  (newIORef, readIORef, writeIORef)
+import           Data.IORef                         (newIORef, readIORef,
+                                                     writeIORef)
 import           Data.Maybe                         (fromMaybe)
 import           Data.Monoid                        ((<>))
 import           Data.String                        (fromString)
-import           Network.HTTP.Types          hiding (Header, ResponseHeaders)
-import           Network.Wai                 (Application, Request, Response,
-                                              ResponseReceived,
-                                              requestBody,
-                                              responseLBS,
+import           Network.HTTP.Types                 hiding (Header,
+                                                     ResponseHeaders)
+import           Network.Wai                        (Application, Request,
+                                                     Response, ResponseReceived,
+                                                     requestBody, responseLBS,
                                                      strictRequestBody)
 import           Servant.API                        ((:<|>) (..))
 import           Servant.Server.Internal.ServantErr

servant-server/src/Servant/Server/Internal/ServantErr.hs

@@ -5,7 +5,7 @@ module Servant.Server.Internal.ServantErr where
 import qualified Data.ByteString.Char8 as BS
 import qualified Data.ByteString.Lazy  as LBS
 import qualified Network.HTTP.Types    as HTTP
-import           Network.Wai               (responseLBS, Response)
+import           Network.Wai           (Response, responseLBS)
 
 data ServantErr = ServantErr { errHTTPCode     :: Int
                              , errReasonPhrase :: String

servant-server/src/Servant/Utils/StaticFiles.hs

@@ -7,10 +7,11 @@ module Servant.Utils.StaticFiles (
   serveDirectory,
  ) where
 
-import System.FilePath (addTrailingPathSeparator)
-import Network.Wai.Application.Static (staticApp, defaultFileServerSettings)
+import           Network.Wai.Application.Static (defaultFileServerSettings,
+                                                 staticApp)
 import           Servant.API.Raw                (Raw)
 import           Servant.Server                 (Server)
+import           System.FilePath                (addTrailingPathSeparator)
 #if !MIN_VERSION_wai_app_static(3,1,0)
 import           Filesystem.Path.CurrentOS      (decodeString)
 #endif

servant-server/test/Servant/Utils/StaticFilesSpec.hs

@@ -8,10 +8,12 @@ module Servant.Utils.StaticFilesSpec where
 import           Control.Exception         (bracket)
 import           Data.Proxy                (Proxy (Proxy))
 import           Network.Wai               (Application)
-import System.Directory (getCurrentDirectory, setCurrentDirectory, createDirectory)
+import           System.Directory          (createDirectory,
+                                            getCurrentDirectory,
+                                            setCurrentDirectory)
 import           System.IO.Temp            (withSystemTempDirectory)
-import Test.Hspec (Spec, describe, it, around_)
-import Test.Hspec.Wai (with, get, shouldRespondWith)
+import           Test.Hspec                (Spec, around_, describe, it)
+import           Test.Hspec.Wai            (get, shouldRespondWith, with)
 
 import           Servant.API               (JSON)
 import           Servant.API.Alternative   ((:<|>) ((:<|>)))

servant/default.nix

@@ -1,24 +0,0 @@
-{ mkDerivation, aeson, attoparsec, base, bytestring
-, bytestring-conversion, case-insensitive, directory, doctest
-, filemanip, filepath, hspec, http-media, http-types, network-uri
-, parsec, QuickCheck, quickcheck-instances, stdenv
-, string-conversions, text, url, vault
-}:
-mkDerivation {
-  pname = "servant";
-  version = "0.5";
-  src = ./.;
-  buildDepends = [
-    aeson attoparsec base bytestring bytestring-conversion
-    case-insensitive http-media http-types network-uri
-    string-conversions text vault
-  ];
-  testDepends = [
-    aeson attoparsec base bytestring directory doctest filemanip
-    filepath hspec parsec QuickCheck quickcheck-instances
-    string-conversions text url
-  ];
-  homepage = "http://haskell-servant.github.io/";
-  description = "A family of combinators for defining webservices APIs";
-  license = stdenv.lib.licenses.bsd3;
-}

servant/test/Servant/API/ContentTypesSpec.hs

@@ -12,13 +12,13 @@ import           Data.Monoid
 #endif
 import           Control.Arrow
 import           Data.Aeson
-import           Data.Either
-import           Data.Function              (on)
-import           Data.Proxy
 import           Data.ByteString.Char8     (ByteString, append, pack)
 import qualified Data.ByteString.Lazy      as BSL
+import           Data.Either
+import           Data.Function             (on)
 import           Data.List                 (maximumBy)
 import           Data.Maybe                (fromJust, isJust, isNothing)
+import           Data.Proxy
 import           Data.String               (IsString (..))
 import           Data.String.Conversions   (cs)
 import qualified Data.Text                 as TextS
@@ -57,15 +57,15 @@ spec = describe "Servant.API.ContentTypes" $ do
         let p = Proxy :: Proxy FormUrlEncoded
 
         it "has mimeUnrender reverse mimeRender" $ do
-            property $ \x -> all (/= mempty) x
+            property $ \x -> mempty `notElem` x
                 ==> mimeUnrender p (mimeRender p x) == Right (x::[(TextS.Text,TextS.Text)])
 
         it "has mimeUnrender reverse exportParams (Network.URL)" $ do
-            property $ \x -> all (/= mempty) x
+            property $ \x -> mempty `notElem` x
                 ==> (mimeUnrender p . cs . exportParams . map (cs *** cs) $ x) == Right (x::[(TextS.Text,TextS.Text)])
 
         it "has importParams (Network.URL) reverse mimeRender" $ do
-            property $ \x -> all (/= mempty) x
+            property $ \x -> mempty `notElem` x
                 ==> (fmap (map (cs *** cs)) . importParams . cs . mimeRender p $ x) == Just (x::[(TextS.Text,TextS.Text)])
 
     describe "The PlainText Content-Type type" $ do