Tighten some loops, change more interface.

This will save.. five comparisons.. occasionally? But it's a more
transparent design, and it seems more charitable to group interface
changes together.

README.md

@@ -12,9 +12,5 @@ connections when possible."
 λ: rules <- getRulesets
 λ: let Just it = parseURI "http://httpsnow.org"
 λ: rewriteURL rules it
-https://httpsnow.org
-λ: :m + Network.HTTP.Client Network.HTTP.Client.TLS Control.Applicative Control.Lens
-λ: (req, hub) <- (,) <*> getUri <$> parseUrl "https://github.com/fmap/https-everywhere-rules"
-λ: newManager tlsManagerSettings >>= httpNoBody req <&> destroyCookieJar . responseCookieJar >>= mapM (rewriteCookie rules hub)
-[Cookie {cookie_name = "_gh_sess", cookie_value = "eyJzZXNzaW9uX2lkIjoiNjBlM2FiOTIxNTdhZTNhNDE5YWQ0ZTk4ZWQzNDRjMjEiLCJzcHlfcmVwbyI6ImZtYXAvaHR0cHMtZXZlcnl3aGVyZS1ydWxlcyIsInNweV9yZXBvX2F0IjoxNDA4ODk2OTM2LCJfY3NyZl90b2tlbiI6IktkbTlwN2JqNGptVmhrYjFIUm9BbkV0a1JTQXRDUXJid2g4VWo4N1g0Q1U9In0%3D--d378daa262b8c12bb82246d5de6b3adc353a3db7", cookie_expiry_time = 3013-12-25 00:00:00 UTC, cookie_domain = "github.com", cookie_path = "/", cookie_creation_time = 2014-08-24 16:15:37.815144 UTC, cookie_last_access_time = 2014-08-24 16:15:37.815144 UTC, cookie_persistent = False, cookie_host_only = True, cookie_secure_only = True, cookie_http_only = True},Cookie {cookie_name = "logged_in", cookie_value = "no", cookie_expiry_time = 2034-08-24 16:15:36 UTC, cookie_domain = "github.com", cookie_path = "/", cookie_creation_time = 2014-08-24 16:15:37.815144 UTC, cookie_last_access_time = 2014-08-24 16:15:37.815144 UTC, cookie_persistent = True, cookie_host_only = False, cookie_secure_only = True, cookie_http_only = True}]
+Just https://httpsnow.org
 ```

examples/CountUpgradeable.hs

@@ -7,6 +7,7 @@ import qualified "foldl" Control.Foldl as Foldl
 import "base" Control.Monad (forever)
 import "base" Data.Bool (bool)
 import "https-everywhere-rules" Data.HTTPSEverywhere.Rules (rewriteURL, RuleSet, getRulesets)
+import "base" Data.Maybe (isJust)
 import "base" Data.Monoid (Sum(..))
 import "network-uri" Network.URI (URI, parseURI)
 import "pipes" Pipes (Pipe, Producer, lift, yield, await, (>->))
@@ -17,9 +18,7 @@ parse :: Monad m => Pipe String URI m ()
 parse = forever $ parseURI <$> await >>= maybe (return ()) yield
 
 check :: [RuleSet] -> Pipe URI Bool IO ()
-check rs = forever $ do
-  src <- await
-  yield $ src /= rewriteURL rs src
+check rs = forever $ await >>= yield . isJust . rewriteURL rs
 
 fold :: Monad m => Fold a b -> Producer a m () -> m b
 fold (Fold step begin done) = Pipes.fold step begin done

examples/RedirectProxy.hs

@@ -4,6 +4,7 @@
 
 module Main (main) where
 
+import "base" Data.Maybe (maybe)
 import "base" Data.Monoid ((<>))
 import "bytestring" Data.ByteString.Char8 (pack, unpack)
 import "http-proxy" Network.HTTP.Proxy (runProxySettings, defaultProxySettings, Settings(..), Request(..))
@@ -17,9 +18,7 @@ httpRedirect to = responseLBS status302 [("Location", pack . show $ to)] ""
 
 tryHTTPS :: [RuleSet] -> Request -> Either Response Request
 tryHTTPS rs Request{..} = case parseURI . unpack $ requestPath <> queryString of
-  Just uri ->
-    let rewrite = rewriteURL rs uri in
-      if uri == rewrite then return Request{..} else Left $ httpRedirect rewrite
+  Just uri -> maybe (return Request{..}) (Left . httpRedirect) (rewriteURL rs uri)
   Nothing -> return Request{..}
 
 main :: IO ()

src/Data/HTTPSEverywhere/Rules.hs

@@ -6,27 +6,24 @@ module Data.HTTPSEverywhere.Rules (
 ) where
 
 import Prelude hiding (null, head)
-import Control.Lens ((<&>),(&))
 import Data.Bool (bool)
 import Data.Functor.Infix ((<$$>), (<$$$>))
-import Data.Maybe (fromMaybe)
 import Network.HTTP.Client (Cookie)
 import Network.URI (URI)
 import Pipes ((>->))
 import Pipes.Prelude (head, null)
-import Control.Monad (join)
 import Control.Monad.Identity (Identity(runIdentity))
 import Data.HTTPSEverywhere.Rules.Internal (getRulesets, getRulesetsMatching, havingRulesThatTrigger, havingCookieRulesThatTrigger, setSecureFlag, RuleSet)
 
-rewriteURL' :: Monad m => [RuleSet] -> URI -> m URI
-rewriteURL' rs url = getRulesetsMatching rs url >-> havingRulesThatTrigger url & head <&> fromMaybe url . join
+rewriteURL' :: Monad m => [RuleSet] -> URI -> m (Maybe URI)
+rewriteURL' rs url = head $ getRulesetsMatching rs url >-> havingRulesThatTrigger url
 
-rewriteURL :: [RuleSet] -> URI -> URI
+rewriteURL :: [RuleSet] -> (URI -> Maybe URI)
 rewriteURL = runIdentity <$$> rewriteURL'
 
-rewriteCookie' :: Monad m => [RuleSet] -> URI -> Cookie -> m Cookie
-rewriteCookie' rs url cookie = null producer <&> setSecureFlag cookie `bool` cookie
+rewriteCookie' :: Monad m => [RuleSet] -> URI -> Cookie -> m (Maybe Cookie)
+rewriteCookie' rs url cookie = Just (setSecureFlag cookie) `bool` Nothing <$> null producer
   where producer = getRulesetsMatching rs url >-> havingCookieRulesThatTrigger cookie
 
-rewriteCookie :: [RuleSet] -> URI -> Cookie -> Cookie
+rewriteCookie :: [RuleSet] -> URI -> (Cookie -> Maybe Cookie)
 rewriteCookie = runIdentity <$$$> rewriteCookie'

src/Data/HTTPSEverywhere/Rules/Internal.hs

@@ -43,9 +43,9 @@ getRulesetsMatching rs url = each rs
                          >-> filter (flip hasTargetMatching url)
                          >-> filter (not . flip hasExclusionMatching url)
 
-havingRulesThatTrigger :: Monad m => URI -> Pipe RuleSet (Maybe URI) m ()
+havingRulesThatTrigger :: Monad m => URI -> Pipe RuleSet URI m ()
 havingRulesThatTrigger url = flip hasTriggeringRuleOn url <$> await 
-                         >>= maybe (havingRulesThatTrigger url) (yield . Just)
+                         >>= maybe (havingRulesThatTrigger url) yield
 
 havingCookieRulesThatTrigger :: Monad m => Cookie -> Pipe RuleSet Bool m ()
 havingCookieRulesThatTrigger cookie = flip hasTriggeringCookieRuleOn cookie <$> await