* Rewrite function using `compact'.

* Rename `compact' to `compact_line'.
* Added the description for new style in .stylish-haskell.yml
* Added test case for `compact_line'.

4 files changed, 40 insertions, 25 deletions

diff --git a/data/stylish-haskell.yaml b/data/stylish-haskell.yaml
index 080c2f9..cc117e5 100644
--- a/data/stylish-haskell.yaml
+++ b/data/stylish-haskell.yaml
@@ -41,6 +41,7 @@ steps:
       #
       # - compact: A more compact style.
       #
+      # - compact_line: Similar to compact, but wrap each line by `{-#LANGUAGE #-}'.
       # Default: vertical.
       style: vertical
 
diff --git a/src/Language/Haskell/Stylish/Config.hs b/src/Language/Haskell/Stylish/Config.hs
index 32eb55d..2dd79a8 100644
--- a/src/Language/Haskell/Stylish/Config.hs
+++ b/src/Language/Haskell/Stylish/Config.hs
@@ -178,9 +178,9 @@ parseLanguagePragmas config o = LanguagePragmas.step
     <*> o A..:? "remove_redundant" A..!= True
   where
     styles =
-        [ ("vertical", LanguagePragmas.Vertical)
-        , ("compact",  LanguagePragmas.Compact)
-        , ("line",     LanguagePragmas.Line)]
+        [ ("vertical",     LanguagePragmas.Vertical)
+        , ("compact",      LanguagePragmas.Compact)
+        , ("compact_line", LanguagePragmas.CompactLine)]
 
 
 --------------------------------------------------------------------------------
diff --git a/src/Language/Haskell/Stylish/Step/LanguagePragmas.hs b/src/Language/Haskell/Stylish/Step/LanguagePragmas.hs
index c147ade..48db19b 100644
--- a/src/Language/Haskell/Stylish/Step/LanguagePragmas.hs
+++ b/src/Language/Haskell/Stylish/Step/LanguagePragmas.hs
@@ -24,7 +24,7 @@ import Language.Haskell.Stylish.Util
 data Style
     = Vertical
     | Compact
-    | Line
+    | CompactLine
     deriving (Eq, Show)
 
 
@@ -56,27 +56,27 @@ compactPragmas columns pragmas' = wrap columns "{-# LANGUAGE" 13 $
 
 
 --------------------------------------------------------------------------------
-linePragmas :: Int -> [String] -> Lines
-linePragmas _ [] = []
-linePragmas columns (p:pragmas') =
-  let (ls, curr, _) = foldl stp ([], p, length p) pragmas'
-      ps = ls ++ [curr]
-      longest = maximum $ map length ps
-  in map (wrapLANGUAGE . padRight longest) ps
+compactLinePragmas :: Int -> [String] -> Lines
+compactLinePragmas _ [] = []
+compactLinePragmas columns pragmas' =
+  let maxWidth = columns - 14
+      prags = map truncateComma $ wrap maxWidth "" 1 $
+                map (++ ",") (init pragmas') ++ [last pragmas']
+      longest = maximum $ map length prags
+  in map (wrapLANGUAGE . padRight longest) prags
   where
-    maxWidth = columns - 17
-    stp (ls, curr, width) str
-      | width' > maxWidth = (ls ++ [curr], str, len)
-      | otherwise         = (ls, curr ++ ", " ++ str, width')
-      where
-        len = length str
-        width' = width + 2 + len
-    wrapLANGUAGE ps = "{-# LANGUAGE " ++ ps ++  " #-}"
+    wrapLANGUAGE ps = "{-# LANGUAGE" ++ ps ++  " #-}"
+
+truncateComma :: String -> String
+truncateComma "" = ""
+truncateComma xs
+    | last xs == ',' = init xs
+    | otherwise      = xs
 
 prettyPragmas :: Int -> Int -> Style -> [String] -> Lines
 prettyPragmas _       longest Vertical = verticalPragmas longest
 prettyPragmas columns _       Compact  = compactPragmas columns
-prettyPragmas columns _       Line     = linePragmas columns
+prettyPragmas columns _       CompactLine = compactLinePragmas columns
 
 --------------------------------------------------------------------------------
 -- | Filter redundant (and duplicate) pragmas out of the groups. As a side
diff --git a/tests/Language/Haskell/Stylish/Step/LanguagePragmas/Tests.hs b/tests/Language/Haskell/Stylish/Step/LanguagePragmas/Tests.hs
index d26c6a4..b4f06b6 100644
--- a/tests/Language/Haskell/Stylish/Step/LanguagePragmas/Tests.hs
+++ b/tests/Language/Haskell/Stylish/Step/LanguagePragmas/Tests.hs
@@ -5,14 +5,14 @@ module Language.Haskell.Stylish.Step.LanguagePragmas.Tests
 
 
 --------------------------------------------------------------------------------
-import           Test.Framework                      (Test, testGroup)
-import           Test.Framework.Providers.HUnit      (testCase)
-import           Test.HUnit                          (Assertion, (@=?))
+import Test.Framework                 (Test, testGroup)
+import Test.Framework.Providers.HUnit (testCase)
+import Test.HUnit                     (Assertion, (@=?))
 
 
 --------------------------------------------------------------------------------
-import           Language.Haskell.Stylish.Step.LanguagePragmas
-import           Language.Haskell.Stylish.Tests.Util
+import Language.Haskell.Stylish.Step.LanguagePragmas
+import Language.Haskell.Stylish.Tests.Util
 
 
 --------------------------------------------------------------------------------
@@ -113,3 +113,17 @@ case05 = expected @=? testStep (step 80 Vertical False) input
         , "{-# LANGUAGE Trustworthy #-}"
         , "#endif"
         ]
+
+case06 :: Assertion
+case06 = expected @=? testStep (step 80 CompactLine True) input
+  where
+    input = unlines
+        [ "{-# LANGUAGE TypeOperators, StandaloneDeriving, DeriveDataTypeable,"
+        , "    TemplateHaskell #-}"
+        , "{-# LANGUAGE TemplateHaskell, ViewPatterns #-}"
+        ]
+    expected = unlines
+        [ "{-# LANGUAGE DeriveDataTypeable, StandaloneDeriving, " ++
+          "TemplateHaskell #-}"
+        , "{-# LANGUAGE TypeOperators, ViewPatterns                             #-}"
+        ]