Files
rlp/src/RLP/Syntax.hs
crumbtoo cae0939f0c where
2024-01-15 07:47:23 -07:00

160 lines
4.6 KiB
Haskell

-- recursion-schemes
{-# LANGUAGE DeriveFunctor, DeriveFoldable, DeriveTraversable #-}
-- recursion-schemes
{-# LANGUAGE TemplateHaskell, TypeFamilies #-}
{-# LANGUAGE OverloadedStrings, PatternSynonyms #-}
module Rlp.Syntax
( RlpExpr(..)
, RlpExpr'
, RlpExprF(..)
, RlpExprF'
, Decl(..)
, Decl'
, Bind(..)
, Where
, Where'
, ConAlt(..)
, Type(..)
, pattern (:->)
, Assoc(..)
, VarId(..)
, ConId(..)
, Pat(..)
, Pat'
, Lit(..)
, Lit'
, Name
-- TODO: ugh move this somewhere else later
, showsTernaryWith
-- * Convenience re-exports
, Text
)
where
----------------------------------------------------------------------------------
import Data.Text (Text)
import Data.Text qualified as T
import Data.String (IsString(..))
import Data.Functor.Foldable.TH (makeBaseFunctor)
import Data.Functor.Classes
import Lens.Micro
import Core.Syntax hiding (Lit)
import Core (HasRHS(..), HasLHS(..))
----------------------------------------------------------------------------------
newtype RlpProgram b = RlpProgram [Decl RlpExpr b]
-- | The @e@ parameter is used for partial results. When parsing an input, we
-- first parse all top-level declarations in order to extract infix[lr]
-- declarations. This process yields a @[Decl (Const Text) Name]@, where @Const
-- Text@ stores the remaining unparsed function bodies. Once infixities are
-- accounted for, we may complete the parsing task and get a proper @[Decl
-- RlpExpr Name]@.
data Decl e b = FunD VarId [Pat b] (e b) (Where b)
| TySigD [VarId] Type
| DataD ConId [Name] [ConAlt]
| InfixD Assoc Int Name
deriving Show
type Decl' e = Decl e Name
data Assoc = InfixL
| InfixR
| Infix
deriving Show
data ConAlt = ConAlt ConId [Type]
deriving Show
data RlpExpr b = LetE [Bind b] (RlpExpr b)
| VarE VarId
| ConE ConId
| LamE [Pat b] (RlpExpr b)
| CaseE (RlpExpr b) [(Alt b, Where b)]
| IfE (RlpExpr b) (RlpExpr b) (RlpExpr b)
| AppE (RlpExpr b) (RlpExpr b)
| LitE (Lit b)
deriving Show
type RlpExpr' = RlpExpr Name
type Where b = [Bind b]
type Where' = [Bind Name]
-- do we want guards?
data Alt b = AltA (Pat b) (RlpExpr b)
deriving Show
data Bind b = PatB (Pat b) (RlpExpr b)
| FunB VarId [Pat b] (RlpExpr b)
deriving Show
data VarId = NameVar Text
| SymVar Text
deriving Show
instance IsString VarId where
-- TODO: use symvar if it's an operator
fromString = NameVar . T.pack
data ConId = NameCon Text
| SymCon Text
deriving Show
data Pat b = VarP VarId
| LitP (Lit b)
| ConP ConId [Pat b]
deriving Show
type Pat' = Pat Name
data Lit b = IntL Int
| CharL Char
| ListL [RlpExpr b]
deriving Show
type Lit' = Lit Name
-- instance HasLHS Alt Alt Pat Pat where
-- _lhs = lens
-- (\ (AltA p _) -> p)
-- (\ (AltA _ e) p' -> AltA p' e)
-- instance HasRHS Alt Alt RlpExpr RlpExpr where
-- _rhs = lens
-- (\ (AltA _ e) -> e)
-- (\ (AltA p _) e' -> AltA p e')
makeBaseFunctor ''RlpExpr
deriving instance (Show b, Show a) => Show (RlpExprF b a)
type RlpExprF' = RlpExprF Name
-- society if derivable Show1
instance (Show b) => Show1 (RlpExprF b) where
liftShowsPrec sp _ p m = case m of
(LetEF bs e) -> showsBinaryWith showsPrec sp "LetEF" p bs e
(VarEF n) -> showsUnaryWith showsPrec "VarEF" p n
(ConEF n) -> showsUnaryWith showsPrec "ConEF" p n
(LamEF bs e) -> showsBinaryWith showsPrec sp "LamEF" p bs e
(CaseEF e as) -> showsBinaryWith sp showsPrec "CaseEF" p e as
(IfEF a b c) -> showsTernaryWith sp sp sp "IfEF" p a b c
(AppEF f x) -> showsBinaryWith sp sp "AppEF" p f x
(LitEF l) -> showsUnaryWith showsPrec "LitEF" p l
showsTernaryWith :: (Int -> x -> ShowS)
-> (Int -> y -> ShowS)
-> (Int -> z -> ShowS)
-> String -> Int
-> x -> y -> z
-> ShowS
showsTernaryWith sa sb sc name p a b c = showParen (p > 10)
$ showString name
. showChar ' ' . sa 11 a
. showChar ' ' . sb 11 b
. showChar ' ' . sc 11 c