Indentation, proper braces with arrowInstType

diff --git a/Expr.hs b/Expr.hs
index 52c99d2..13fdaf7 100644 (file)
--- a/Expr.hs
+++ b/Expr.hs
@@ -96,66 +96,70 @@ showIntercalate i [x] = x
 showIntercalate i (x:xs) = x . i . showIntercalate i xs
 
 instance Show BoolExpr where
-       showsPrec d (Equal e1 e2) = showParen (d>8) $
-                                   showsPrec 9 e1 .
-                                   showString " == " .
-                                   showsPrec 9 e2 
-       showsPrec d (Pairwise v1 v2 be e1 e2) =
-                       showParen (d>10) $
-                       showString "allZipWith " .
-                       showParen True ( 
-                               showString "\\" .
-                               showString v1 .
-                               showChar ' ' .
-                               showString v2 . 
-                               showString " -> " .
-                               showsPrec 0 be
-                       ) .
-                       showChar ' ' .
-                       showsPrec 11 e1 .
-                       showChar ' ' .
-                       showsPrec 11 e2
-       showsPrec d (Condition v1 v2 t be1 be2) = 
-                       showParen (d>6) $
-                       showString "forall " . 
-                       showString v1 . 
-                       showString " :: " .
-                       arrowInstType False t .
-                       showString ", " .
-                       showString v2 . 
-                       showString " :: " .
-                       arrowInstType True t .
-                       showString ".\n" .
-                       showsPrec 9 be1 .
-                       showString " ==> " .
-                       showsPrec 6 be2
-       showsPrec d (UnCond v1 b t be1) = 
-                       showParen (d>6) $
-                       showString "forall " . 
-                       showString v1 . 
-                       showString " :: " .
-                       arrowInstType b t .
-                       showString ".\n" .
-                       showsPrec 6 be1
-       showsPrec d (TypeVarInst i be) = 
-                       showParen (d>6) $
-                       showString "forall types t" .
-                       shows (2*i-1) .
-                       showString ", t" .
-                       shows (2*i) . 
-                       showString ", function g" .
-                       shows i .
-                       showString " :: t" .
-                       shows (2*i-1) .
-                       showString " -> t" .
-                       shows (2*i) . 
-                       showString ".\n" .
-                       showsPrec 6 be
-
-arrowInstType :: Bool -> Typ -> ShowS
-arrowInstType b Int                    = showString "Int" 
-arrowInstType False (TVar (TypVar i))  = showString "t" .  shows (2*i-1)
-arrowInstType True (TVar (TypVar i))   = showString "t" .  shows (2*i)
-arrowInstType b (Arrow t1 t2)          = arrowInstType b t1 .
-                                         showString " -> " .
-                                         arrowInstType b t2
+       show (Equal e1 e2) = showsPrec 9 e1 $
+                            showString " == " $
+                            showsPrec 9 e2 ""
+       show (Pairwise v1 v2 be e1 e2) =
+                       "allZipWith " ++
+                       "( " ++
+                       "\\" ++
+                       v1 ++
+                       " " ++
+                       v2 ++
+                       " -> " ++
+                       show be ++
+                       ")" ++
+                       " " ++
+                       showsPrec 11 e1 "" ++
+                       " " ++
+                       showsPrec 11 e2 ""
+       show (Condition v1 v2 t be1 be2) = 
+                       "forall " ++
+                       v1 ++
+                       " :: " ++
+                       arrowInstType False t ++
+                       ", " ++
+                       v2 ++
+                       " :: " ++
+                       arrowInstType True t ++
+                       ".\n" ++
+                       indent 2 (show be1) ++
+                       "==>\n" ++
+                       indent 2 (show be2)
+       show (UnCond v1 b t be1) = 
+                       "forall " ++
+                       v1 ++
+                       " :: " ++
+                       arrowInstType b t ++
+                       ".\n" ++
+                       indent 2 (show be1)
+       show (TypeVarInst i be) = 
+                       "forall types t" ++
+                       show (2*i-1) ++
+                       ", t" ++
+                       show (2*i) ++
+                       ", function g" ++
+                       show i ++
+                       " :: t" ++
+                       show (2*i-1) ++
+                       " -> t" ++
+                       show (2*i) ++ 
+                       ".\n" ++
+                       indent 2 (show be)
+
+indent n = unlines . map (replicate n ' ' ++) . lines
+
+arrowInstType :: Bool -> Typ -> String
+arrowInstType b = ait 0
+  where 
+       ait _ Int                       = "Int" 
+       ait _ (TVar (TypVar i)) | not b = "t" ++  show (2*i-1)
+                                |     b = "t" ++  show (2*i)
+       ait d (Arrow t1 t2)             = paren (d>9) $ 
+                                                 ait 10 t1 ++ " -> " ++ ait 9 t2 
+       ait d (List t)                  = "[" ++ ait 0 t ++ "]"
+       ait d (TEither t1 t2)           = "Either " ++ ait 11 t1 ++ 
+                                                " " ++ ait 11 t2
+       ait d (TPair t1 t2)             = "(" ++ ait 0 t1 ++ ", " ++ ait 0 t2 ++ ")"
+
+paren b p   =  if b then "(" ++ p ++ ")" else p