Migrate from Spock to Scotty

package.yaml

@@ -48,7 +48,7 @@ executables:
     - concurrency
     - ghc
     - mtl
-    - Spock
+    - scotty
     - text
     - time
     - wai

server/Main.hs

@@ -2,19 +2,27 @@
 module Main where
 
 import Control.Monad.Trans(liftIO)
-import Control.Monad.Trans.State.Strict(runStateT)
+import Control.Monad.Trans.Class(lift)
+import Control.Monad.Trans.State.Strict(runStateT, evalStateT, StateT)
+-- We need to distinguish State.get from Scotty.get
+import qualified Control.Monad.Trans.State.Strict as State
 import Data.IORef(IORef, newIORef, readIORef, writeIORef)
-import Data.Text(pack, toLower, isInfixOf)
-import Data.Text.Encoding(decodeUtf8)
+import Data.Text.Lazy(pack, toLower, isInfixOf)
+import Data.Text.Lazy.Encoding(decodeUtf8)
 import Data.Time(getCurrentTime)
 import Network.Wai(Request, requestHeaders)
 -- Take the `Dev` off the end to get more standardized server logs.
 import Network.Wai.Middleware.RequestLogger(logStdoutDev)
 import Network.Wai.Middleware.Static(staticPolicy, addBase)
 import System.Random(StdGen, getStdGen)
-import Web.Spock(SpockM, file, text, get, post, root, spock, runSpock, json,
-                 getState, middleware, param, request)
-import Web.Spock.Config(PoolOrConn(PCNoDatabase), defaultSpockCfg)
+
+import Web.Scotty(ScottyM, file, text, get, post, scotty, json,
+                  middleware, param, request)
+
+
+--import Web.Spock(SpockM, file, text, get, post, root, spock, runSpock, json,
+--                 getState, middleware, param, request)
+--import Web.Spock.Config(PoolOrConn(PCNoDatabase), defaultSpockCfg)
 
 import Random(pickItem)
 
@@ -23,7 +31,6 @@ import TopicRegistry(topicNames, findCachers, TopicRegistry, makeTopicRegistry)
 import ThreadPool(newThreadPool)
 
 
-data MySession = EmptySession
 data MyAppState = IOState (IORef StdGen) TopicRegistry
 
 
@@ -32,8 +39,7 @@ main = do
     (pool, rng) <- getStdGen >>= runStateT (newThreadPool 4)
     registry <- makeTopicRegistry pool
     ref <- newIORef rng
-    spockCfg <- defaultSpockCfg EmptySession PCNoDatabase (IOState ref registry)
-    runSpock 8765 (spock spockCfg app)
+    scotty 8765 . evalStateT app $ IOState ref registry
 
 
 isMobile :: Request -> Bool
@@ -46,22 +52,22 @@ isMobile req = let
     maybe False isMobileAgent maybeUseragent
 
 
-app :: SpockM () MySession MyAppState ()
+app :: StateT MyAppState ScottyM ()
 app = do
-    middleware logStdoutDev
+    lift $ middleware logStdoutDev
     -- NOTE: these next two are relative to the current working directory when
     -- you execute the program! So, you need to run it from the right place.
-    middleware (staticPolicy (addBase "static"))
-    get root $ do
+    lift $ middleware (staticPolicy (addBase "static"))
+    lift $ get "/" $ do
         req <- request
         file "text/html" $ if isMobile req then "static/mobile.html"
                                            else "static/index.html"
-    post "bugreport" $ text . pack $ "bug report received!\n"
-    get "topics" $ json topicNames
-    get "situation" $ do
+    lift $ post "/bugreport" $ text . pack $ "bug report received!\n"
+    lift $ get "/topics" $ json topicNames
+    lift $ get "/situation" $ do
         liftIO $ getCurrentTime >>= print
         requested <- param "topics"
-        (IOState ioRng registry) <- getState
+        (IOState ioRng registry) <- State.get
         let malformed = Left "no topics selected"
         case maybe malformed (findCachers registry) requested of
             Left err -> text . pack $ err

src/EDSL.hs

@@ -99,6 +99,10 @@ makeAlertableCall call alert = makeCompleteCall_ completeCall
 makePass :: Action
 makePass = makeCall T.Pass
 
+-- This keeps the last call of the given action, but throws away all the
+-- definitions and constraints added from it. Should be used very rarely: it was
+-- created to practice pretending to have the queen of trump when you've got a
+-- 10-card fit and partner asks for keycards.
 stealCall :: Action -> Action
 stealCall = makeCompleteCall_ . extractLastCall