Added `line' language pragma style. It is similar to `compact` but put "{-# LANGUAGE " for each line instead of padding.

2 files changed, 22 insertions, 1 deletions

diff --git a/src/Language/Haskell/Stylish/Config.hs b/src/Language/Haskell/Stylish/Config.hs
index 346fcad..07b89e0 100644
--- a/src/Language/Haskell/Stylish/Config.hs
+++ b/src/Language/Haskell/Stylish/Config.hs
@@ -174,7 +174,7 @@ parseLanguagePragmas config o = LanguagePragmas.step
     styles =
         [ ("vertical", LanguagePragmas.Vertical)
         , ("compact",  LanguagePragmas.Compact)
-        ]
+        , ("line",     LanguagePragmas.Line)]
 
 
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diff --git a/src/Language/Haskell/Stylish/Step/LanguagePragmas.hs b/src/Language/Haskell/Stylish/Step/LanguagePragmas.hs
index 8d71c68..53657e0 100644
--- a/src/Language/Haskell/Stylish/Step/LanguagePragmas.hs
+++ b/src/Language/Haskell/Stylish/Step/LanguagePragmas.hs
@@ -24,6 +24,7 @@ import           Language.Haskell.Stylish.Util
 data Style
     = Vertical
     | Compact
+    | Line
     deriving (Eq, Show)
 
 
@@ -57,9 +58,29 @@ compactPragmas columns pragmas' = wrap columns "{-# LANGUAGE" 13 $
 
 
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+linePragmas :: Int -> [String] -> Lines
+linePragmas _ [] = []
+linePragmas columns (p:pragmas') =
+  let (ls, curr, _) = foldl step ([], p, length p) pragmas'
+      ps = ls ++ [curr]
+      longest = maximum $ map length ps
+  in map (wrapLANGUAGE . padRight longest) ps
+  where
+    maxWidth = columns - 17
+    step (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 ++  " #-}"
+
+
+--------------------------------------------------------------------------------
 prettyPragmas :: Int -> Style -> [String] -> Lines
 prettyPragmas _       Vertical = verticalPragmas
 prettyPragmas columns Compact  = compactPragmas columns
+prettyPragmas columns Line     = linePragmas    columns
 
 
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