ohhhh

src/Rlp/AltSyntax.hs

@@ -3,7 +3,7 @@ module Rlp.AltSyntax
     (
     -- * AST
       Program(..), Decl(..), ExprF(..), Pat(..)
-    , RlpExprF, RlpExpr
+    , RlpExprF, RlpExpr, Binding(..)
     , DataCon(..), Type(..)
 
     , Core.Name, PsName
@@ -16,6 +16,7 @@ module Rlp.AltSyntax
 import Data.Functor.Sum
 import Control.Comonad.Cofree
 import Data.Fix
+import Data.Function            (fix)
 
 import Text.Show.Deriving
 import Data.Text                qualified as T
@@ -44,6 +45,11 @@ data Type b = VarT b
             deriving Show
 
 data ExprF b a = InfixEF b a a
+               | LetEF Core.Rec [Binding b a] a
+
+data Binding b a = FunB b [Pat b] a
+                 | VarB (Pat b) a
+    deriving Show
 
 -- type Expr b = Cofree (ExprF b)
 
@@ -54,6 +60,7 @@ type RlpExpr b = Fix (RlpExprF b)
 data Pat b = VarP b
     deriving Show
 
+deriveShow1 ''Binding
 deriveShow1 ''ExprF
 deriving instance (Show b, Show a) => Show (ExprF b a)
 
@@ -76,10 +83,28 @@ instance (Pretty b, Pretty a) => Pretty (Decl b a) where
     prettyPrec = prettyPrec1
 
 instance (Pretty b) => Pretty1 (Decl b) where
-    liftPrettyPrec pr p (FunD f as e) = maybeParens (p>0) $
+    liftPrettyPrec pr _ (FunD f as e) =
         hsep [ ttext f, hsep (prettyPrec appPrec1 <$> as)
              , "=", pr 0 e ]
 
+    liftPrettyPrec _ _ (DataD f as []) =
+        hsep [ "data", ttext f, hsep (pretty <$> as) ]
+
+    liftPrettyPrec _ _ (DataD f as ds) =
+        hsep [ "data", ttext f, hsep (pretty <$> as), cons ]
+      where
+        cons = vcat $ zipWith (<+>) delims (pretty <$> ds)
+        delims = "=" : repeat "|"
+
+instance (Pretty b) => Pretty (DataCon b) where
+    pretty (DataCon n as) = ttext n <+> hsep (prettyPrec appPrec1 <$> as)
+
+instance (Pretty b) => Pretty (Type b) where
+    prettyPrec _ (VarT n) = ttext n
+    prettyPrec _ (ConT n) = ttext n
+    prettyPrec p (AppT f x) = maybeParens (p>appPrec) $
+        prettyPrec appPrec f <+> prettyPrec appPrec1 x
+
 instance (Pretty b) => Pretty (Pat b) where
     prettyPrec p (VarP b) = prettyPrec p b