From fc74d2df894a0aad13811822cdfcd01200bc1e1b Mon Sep 17 00:00:00 2001
From: Jon Kristensen <jon.kristensen@nejla.com>
Date: Sat, 21 Apr 2012 19:18:43 +0200
Subject: [PATCH 1/3] recommitted version functions, rewritten to work with
 Text and attoparsec

---
 src/Network/XMPP/Utilities.hs | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/src/Network/XMPP/Utilities.hs b/src/Network/XMPP/Utilities.hs
index 794fe0f..7841698 100644
--- a/src/Network/XMPP/Utilities.hs
+++ b/src/Network/XMPP/Utilities.hs
@@ -15,6 +15,7 @@ import Control.Monad.STM
 import Control.Concurrent.STM.TVar
 import Prelude
 
+import qualified Data.Attoparsec.Text as AP
 import qualified Data.Text as Text
 
 
@@ -60,4 +61,26 @@ idGenerator prefix = atomically $ do
 
         -- Characters allowed in IDs.
         repertoire :: String
-        repertoire = ['a'..'z']
\ No newline at end of file
+        repertoire = ['a'..'z']
+
+
+-- Converts a "<major>.<minor>" numeric version number to a @Version@ object.
+versionFromString :: Text.Text -> Maybe Version
+versionFromString s = case AP.parseOnly versionParser s of
+                        Right version -> Just version
+                        Left _ -> Nothing
+
+
+-- Constructs a "Version" based on the major and minor version numbers.
+versionFromNumbers :: Integer -> Integer -> Version
+versionFromNumbers major minor = Version major minor
+
+
+-- Read numbers, a dot, more numbers, and end-of-file.
+versionParser :: AP.Parser Version
+versionParser = do
+    major <- AP.many1 AP.digit
+    AP.skip (\ c -> c == '.')
+    minor <- AP.many1 AP.digit
+    AP.endOfInput
+    return $ Version (read major) (read minor)
\ No newline at end of file

From d33f32d5cc06179e1367214100bb5e39ea4c02bf Mon Sep 17 00:00:00 2001
From: Jon Kristensen <jon.kristensen@nejla.com>
Date: Sat, 21 Apr 2012 19:23:48 +0200
Subject: [PATCH 2/3] removed head and tail

---
 src/Network/XMPP/Utilities.hs | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/Network/XMPP/Utilities.hs b/src/Network/XMPP/Utilities.hs
index 7841698..039924a 100644
--- a/src/Network/XMPP/Utilities.hs
+++ b/src/Network/XMPP/Utilities.hs
@@ -38,8 +38,11 @@ idGenerator prefix = atomically $ do
     next :: TVar [Text.Text] -> IO Text.Text
     next tvar = atomically $ do
         list <- readTVar tvar
-        writeTVar tvar $ tail list
-        return $ head list
+        case list of
+          [] -> error "empty list in Utilities.hs"
+          (x:xs) -> do
+            writeTVar tvar xs
+            return x
 
     -- Generates an infinite and predictable list of IDs, all beginning with the
     -- provided prefix.

From 6b9ebabc0179dbde99108b2635dd5f0e4895bc23 Mon Sep 17 00:00:00 2001
From: Jon Kristensen <jon.kristensen@nejla.com>
Date: Sat, 21 Apr 2012 20:38:31 +0200
Subject: [PATCH 3/3] added rewritten langtag functions using Text and
 attoparsec

---
 src/Network/XMPP/Utilities.hs | 35 +++++++++++++++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

diff --git a/src/Network/XMPP/Utilities.hs b/src/Network/XMPP/Utilities.hs
index 039924a..7be7b6a 100644
--- a/src/Network/XMPP/Utilities.hs
+++ b/src/Network/XMPP/Utilities.hs
@@ -14,6 +14,7 @@ import Network.XMPP.Types
 import Control.Monad.STM
 import Control.Concurrent.STM.TVar
 import Prelude
+import Control.Applicative (many)
 
 import qualified Data.Attoparsec.Text as AP
 import qualified Data.Text as Text
@@ -83,7 +84,37 @@ versionFromNumbers major minor = Version major minor
 versionParser :: AP.Parser Version
 versionParser = do
     major <- AP.many1 AP.digit
-    AP.skip (\ c -> c == '.')
+    AP.skip (== '.')
     minor <- AP.many1 AP.digit
     AP.endOfInput
-    return $ Version (read major) (read minor)
\ No newline at end of file
+    return $ Version (read major) (read minor)
+
+
+-- | Parses, validates, and possibly constructs a "LangTag" object.
+langTag :: Text.Text -> Maybe LangTag
+langTag s = case AP.parseOnly langTagParser s of
+              Right tag -> Just tag
+              Left _ -> Nothing
+
+
+-- Parses a language tag as defined by RFC 1766 and constructs a LangTag object.
+langTagParser :: AP.Parser LangTag
+langTagParser = do
+    -- Read until we reach a '-' character, or EOF. This is the `primary tag'.
+    primTag <- tag
+    -- Read zero or more subtags.
+    subTags <- many subtag
+    AP.endOfInput
+    return $ LangTag primTag subTags
+    where
+        tag :: AP.Parser Text.Text
+        tag = do
+            t <- AP.takeWhile1 $ AP.inClass tagChars
+            return t
+        subtag :: AP.Parser Text.Text
+        subtag = do
+            AP.skip (== '-')
+            subtag <- tag
+            return subtag
+        tagChars :: [Char]
+        tagChars = ['a'..'z'] ++ ['A'..'Z']
\ No newline at end of file