165 lines
4.8 KiB
Haskell
165 lines
4.8 KiB
Haskell
{-# LANGUAGE TemplateHaskell, PatternSynonyms #-}
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module Rlp.AltSyntax
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(
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-- * AST
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Program(..), Decl(..), ExprF(..), Pat(..)
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, RlpExprF, RlpExpr, Binding(..), Alter(..)
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, DataCon(..), Type(..)
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, Core.Name, PsName
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, pattern (Core.:->)
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-- * Optics
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, programDecls
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, _VarP, _FunB, _VarB
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-- * Functor-related tools
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, Fix(..), Cofree(..), Sum(..), pattern Finl, pattern Finr
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)
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where
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--------------------------------------------------------------------------------
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import Data.Functor.Sum
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import Control.Comonad.Cofree
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import Data.Fix
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import Data.Function (fix)
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import Control.Lens
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import Text.Show.Deriving
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import Data.Text qualified as T
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import Data.Pretty
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import Compiler.Types
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import Core.Syntax qualified as Core
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--------------------------------------------------------------------------------
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type PsName = T.Text
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newtype Program b a = Program [Decl b a]
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deriving Show
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programDecls :: Lens' (Program b a) [Decl b a]
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programDecls = lens (\ (Program ds) -> ds) (const Program)
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data Decl b a = FunD b [Pat b] a
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| DataD b [b] [DataCon b]
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| TySigD b (Type b)
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deriving Show
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data DataCon b = DataCon b [Type b]
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deriving Show
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data Type b = VarT b
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| ConT b
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| AppT (Type b) (Type b)
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| FunT
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deriving Show
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instance Core.HasArrowSyntax (Type b) (Type b) (Type b) where
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_arrowSyntax = prism make unmake where
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make (s,t) = FunT `AppT` s `AppT` t
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unmake (FunT `AppT` s `AppT` t) = Right (s,t)
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unmake s = Left s
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data ExprF b a = InfixEF b a a
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| LetEF Core.Rec [Binding b a] a
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| CaseEF a [Alter b a]
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deriving (Functor, Foldable, Traversable)
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data Alter b a = Alter (Pat b) a
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deriving (Show, Functor, Foldable, Traversable)
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data Binding b a = FunB b [Pat b] a
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| VarB (Pat b) a
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deriving (Show, Functor, Foldable, Traversable)
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-- type Expr b = Cofree (ExprF b)
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type RlpExprF b = Sum (Core.ExprF b) (ExprF b)
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type RlpExpr b = Fix (RlpExprF b)
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data Pat b = VarP b
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| ConP b
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| AppP (Pat b) (Pat b)
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deriving Show
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deriveShow1 ''Alter
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deriveShow1 ''Binding
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deriveShow1 ''ExprF
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deriving instance (Show b, Show a) => Show (ExprF b a)
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pattern Finl :: f (Fix (Sum f g)) -> Fix (Sum f g)
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pattern Finl fa = Fix (InL fa)
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pattern Finr :: g (Fix (Sum f g)) -> Fix (Sum f g)
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pattern Finr ga = Fix (InR ga)
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--------------------------------------------------------------------------------
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instance (Pretty b, Pretty a) => Pretty (ExprF b a) where
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prettyPrec = prettyPrec1
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instance (Pretty b, Pretty a) => Pretty (Alter b a) where
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prettyPrec = prettyPrec1
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instance (Pretty b) => Pretty1 (Alter b) where
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liftPrettyPrec pr _ (Alter p e) =
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hsep [ pretty p, "->", pr 0 e]
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instance Pretty b => Pretty1 (ExprF b) where
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liftPrettyPrec pr p (InfixEF o a b) = maybeParens (p>0) $
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pr 1 a <+> pretty o <+> pr 1 b
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liftPrettyPrec pr p (CaseEF e as) = maybeParens (p>0) $
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hsep [ "case", pr 0 e, "of" ]
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$+$ nest 2 (vcat $ liftPrettyPrec pr 0 <$> as)
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instance (Pretty b, Pretty a) => Pretty (Decl b a) where
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prettyPrec = prettyPrec1
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instance (Pretty b) => Pretty1 (Decl b) where
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liftPrettyPrec pr _ (FunD f as e) =
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hsep [ ttext f, hsep (prettyPrec appPrec1 <$> as)
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, "=", pr 0 e ]
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liftPrettyPrec _ _ (DataD f as []) =
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hsep [ "data", ttext f, hsep (pretty <$> as) ]
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liftPrettyPrec _ _ (DataD f as ds) =
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hsep [ "data", ttext f, hsep (pretty <$> as), cons ]
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where
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cons = vcat $ zipWith (<+>) delims (pretty <$> ds)
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delims = "=" : repeat "|"
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liftPrettyPrec _ _ (TySigD n t) =
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hsep [ ttext n, ":", pretty t ]
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instance (Pretty b) => Pretty (DataCon b) where
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pretty (DataCon n as) = ttext n <+> hsep (prettyPrec appPrec1 <$> as)
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-- (->) is given prec `appPrec-1`
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instance (Pretty b) => Pretty (Type b) where
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prettyPrec _ (VarT n) = ttext n
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prettyPrec _ (ConT n) = ttext n
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prettyPrec p (s Core.:-> t) = maybeParens (p>appPrec-1) $
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hsep [ prettyPrec appPrec s, "->", prettyPrec (appPrec-1) t ]
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prettyPrec p (AppT f x) = maybeParens (p>appPrec) $
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prettyPrec appPrec f <+> prettyPrec appPrec1 x
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prettyPrec p FunT = maybeParens (p>0) "->"
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instance (Pretty b) => Pretty (Pat b) where
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prettyPrec p (VarP b) = prettyPrec p b
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prettyPrec p (ConP b) = prettyPrec p b
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prettyPrec p (AppP c x) = maybeParens (p>appPrec) $
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prettyPrec appPrec c <+> prettyPrec appPrec1 x
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instance (Pretty a, Pretty b) => Pretty (Program b a) where
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prettyPrec = prettyPrec1
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instance (Pretty b) => Pretty1 (Program b) where
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liftPrettyPrec pr p (Program ds) = vsep $ liftPrettyPrec pr p <$> ds
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makePrisms ''Pat
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makePrisms ''Binding
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