GenericPretty 0.1.1 → 0.1.2

raw patch · 5 files changed

+33/−17 lines, 5 files

Files

• GenericPretty.cabal +1/−1
• README +4/−2
• TestSuite/SimpleTest.hs +2/−1
• TestSuite/Tests.hs +17/−6
• Text/PrettyPrint/GenericPretty.hs +9/−7

@@ -7,7 +7,7 @@ -- The package version. See the Haskell package versioning policy
 -- (http://www.haskell.org/haskellwiki/Package_versioning_policy) for
 -- standards guiding when and how versions should be incremented.
-Version:             0.1.1
+Version:             0.1.2
 
 -- A short (one-line) description of the package.
 Synopsis:            A generic, derivable, haskell pretty printer.

@@ -15,8 +15,10 @@ import Text.PrettyPrint.GenericPretty
 
 data Tree a = Leaf a | Node (Tree a) (Tree a) deriving (Generic)
-instance (Out a) => Out (Tree a)
 
+instance (Out a) => Out (Tree a) where
+	out = genOut
+
 tree1 :: Tree Int
 tree1 = Node (Node (Leaf 333333) (Leaf (-555555)))(Node (Node(Node(Leaf 888888) 
 		(Leaf 57575757))(Leaf (-14141414)))(Leaf 7777777))
@@ -27,7 +29,7 @@ in a 'LANGUAGE' pragma, or manually by compiling with 'ghc -XDeriveGeneric'.
 
 As can be seen, to use the library one must simply import it, derive 'Generic' 
-on the custom data type, and write an empty instance of 'Out'.
+on the custom data type, and write an instance of 'Out' using 'genOut'.
 
 Then one can use the pretty printing functions, such as 'pp' and 'prettyP'.
 

@@ -4,7 +4,8 @@ 
 data Tree a = Leaf a | Node (Tree a) (Tree a) deriving (Generic)
 
-instance (Out a) => Out (Tree a)
+instance (Out a) => Out (Tree a) where
+	out = genOut
 
 tree1 :: Tree Int
 tree1 = Node (Node (Leaf 333333) (Leaf (-555555)))(Node (Node (Node (Leaf 888888) 

@@ -30,7 +30,8 @@ type Transition q = (q, Char, q)
 
 -- implement 'Out' so we can pretty print
-instance (Out a) => Out (FSM a)
+instance (Out a) => Out (FSM a) where
+	out = genOut
 
 --implementation needed for quickCheck generation of random values
 instance Arbitrary a => Arbitrary (FSM a) where
@@ -52,8 +53,10 @@ 	   
 -- Binary Tree data type
 data BinaryTree a = EmptyBTree | BNode a (BinaryTree a) (BinaryTree a) deriving (Show, Generic)  
-instance (Out a) => Out (BinaryTree a) 
 
+instance (Out a) => Out (BinaryTree a) where
+	out = genOut
+
 instance (Arbitrary a) => Arbitrary (BinaryTree a) where
 	arbitrary = sized arbitTree
 		where 
@@ -91,8 +94,10 @@ 
 -- Tree using record syntax
 data RecordTree a = RNode {val :: a, children :: [RecordTree a]} deriving (Show, Generic)  
-instance (Out a) => Out (RecordTree a)
 
+instance (Out a) => Out (RecordTree a) where
+	out = genOut
+
 instance (Arbitrary a) => Arbitrary (RecordTree a) where
 	arbitrary = sized arbitTree
 		where
@@ -114,7 +119,9 @@ -- tree using infix notation
 data InfixTree a = ILeaf a a | (InfixTree a) :*: (InfixTree a) | (InfixTree a) :+: (InfixTree a) 
 		deriving (Show, Generic)  
-instance (Out a) => Out (InfixTree a)
+		
+instance (Out a) => Out (InfixTree a) where
+	out = genOut
 
 instance (Arbitrary a) => Arbitrary (InfixTree a) where
 	arbitrary = sized arbitTree
@@ -137,7 +144,9 @@ -- infix and record tree, also uses a second user defined type in it's definition, 'Wrap'
 data InfixRecordTree a = IRLeaf (Wrap a) | (:^:) {left :: InfixRecordTree a, right :: InfixRecordTree a} 
 			deriving (Show, Generic)  
-instance (Out a) => Out (InfixRecordTree a)
+			
+instance (Out a) => Out (InfixRecordTree a) where
+	out = genOut
 	
 instance (Arbitrary a) => Arbitrary (InfixRecordTree a) where
 	arbitrary = sized arbitTree
@@ -161,7 +170,9 @@ -- deriving 'Out' and the code would still work, 
 -- but the output wouldn't be identical to show because of how 'Outputable' is implemented
 data Wrap a = Wrap a deriving (Show, Generic)
-instance Out a => Out (Wrap a) 
+
+instance Out a => Out (Wrap a) where
+	out = genOut
 	
 instance Arbitrary a => Arbitrary (Wrap a) where
 	arbitrary = liftM Wrap arbitrary

@@ -1,4 +1,4 @@-{-# LANGUAGE TypeOperators, FlexibleInstances, FlexibleContexts, DefaultSignatures,
+{-# LANGUAGE TypeOperators, FlexibleInstances, FlexibleContexts,
 	OverlappingInstances, UndecidableInstances #-}
 
 {-|
@@ -11,7 +11,7 @@ 
 For examples of usage please see the README file. -}
 
-module Text.PrettyPrint.GenericPretty(pp, prettyP, prettyStr, fullPP, outputTxt, outputStr, Generic, Out(..)) where
+module Text.PrettyPrint.GenericPretty(pp, prettyP, prettyStr, fullPP, outputTxt, outputStr, Generic, Out(..), genOut) where
 
 import Data.List
 import Outputable
@@ -26,15 +26,17 @@   -- | 'out' is the equivalent of Prelude.showsPrec
   -- it generates output identical to show, except for the extra whitespace
   out :: Int -> a -> SDoc
-  -- default out method, converts the type into a sum of products and passes it on to the generic
-  -- pretty printing functions, finally it concatenates all of the SDoc's
-  default out :: (Generic a ,GOut (Rep a)) => Int -> a -> SDoc
-  out n x = sep $ out1 (from x) Pref n False
-  
+      
   -- | 'outList' mimics the behaviour of Prelude.showList
   -- used mainly to output strings correctly, and not as lists of characters
   outList :: Int -> [a] -> SDoc
   outList n xs = brackets (fsep (punctuate comma (map (out n) xs)))
+
+-- | default out method, converts the type into a sum of products and passes it on to the generic
+-- pretty printing functions, finally it concatenates all of the SDoc's
+-- method user must use when implementing 'Out' by saying 'out = genOut'
+genOut :: (Generic a ,GOut (Rep a)) => Int -> a -> SDoc
+genOut n x = sep $ out1 (from x) Pref n False
 
 -- user-defined types that directly implement Outputable are handled here
 -- n marks wether the type needs to be surrounded by parens or not