ppr debug flags

ddump-parsed

src/Data/Pretty.hs

@@ -1,17 +1,51 @@
-{-# LANGUAGE OverloadedStrings #-}
 module Data.Pretty
     ( Pretty(..)
+    , ttext
+    -- * Pretty-printing lens combinators
+    , hsepOf, vsepOf
+    , module Text.PrettyPrint
+    , maybeParens
     )
     where
 ----------------------------------------------------------------------------------
-import Data.String      (IsString(..))
+import Text.PrettyPrint             hiding ((<>))
+import Text.PrettyPrint.HughesPJ    hiding ((<>))
+import Data.String                  (IsString(..))
+import Data.Text.Lens
+import Data.Monoid
+import Data.Text                    qualified as T
+import Control.Lens
 ----------------------------------------------------------------------------------
 
 class Pretty a where
-    -- pretty :: a -> ISeq
-    -- prettyPrec :: a -> Int -> ISeq
+    pretty :: a -> Doc
+    prettyPrec :: Int -> a -> Doc
 
-    -- {-# MINIMAL pretty | prettyPrec #-}
-    -- pretty a = prettyPrec a 0
-    -- prettyPrec a _ = iBracket (pretty a)
+    {-# MINIMAL pretty | prettyPrec #-}
+    pretty = prettyPrec 0
+    prettyPrec a _ = pretty a
+
+instance Pretty String where
+    pretty = Text.PrettyPrint.text
+
+instance Pretty T.Text where
+    pretty = Text.PrettyPrint.text . view unpacked
+
+newtype Showing a = Showing a
+
+instance (Show a) => Pretty (Showing a) where
+    prettyPrec p (Showing a) = fromString $ showsPrec p a ""
+
+deriving via Showing Int instance Pretty Int
+
+--------------------------------------------------------------------------------
+
+ttext :: Pretty t => t -> Doc
+ttext = pretty
+
+hsepOf :: Getting (Endo Doc) s Doc -> s -> Doc
+hsepOf l = foldrOf l (<+>) mempty
+
+vsepOf :: Getting (Endo Doc) s Doc -> s -> Doc
+vsepOf l = foldrOf l ($+$) mempty