infer letrec expressions

small

Makefile_happysrcs

@@ -8,8 +8,8 @@ CABAL_BUILD = dist-newstyle/build/x86_64-osx/ghc-9.6.2/rlp-0.1.0.0/build
 
 all: parsers lexers
 
-parsers: $(CABAL_BUILD)/Rlp/Parse.hs
+parsers: $(CABAL_BUILD)/Rlp/Parse.hs $(CABAL_BUILD)/Core/Parse.hs
-lexers: $(CABAL_BUILD)/Rlp/Lex.hs
+lexers: $(CABAL_BUILD)/Rlp/Lex.hs $(CABAL_BUILD)/Core/Lex.hs
 
 $(CABAL_BUILD)/Rlp/Parse.hs: $(SRC)/Rlp/Parse.y
 	$(HAPPY) $(HAPPY_OPTS) $< -o $@
@@ -17,3 +17,9 @@ $(CABAL_BUILD)/Rlp/Parse.hs: $(SRC)/Rlp/Parse.y
 $(CABAL_BUILD)/Rlp/Lex.hs: $(SRC)/Rlp/Lex.x
 	$(ALEX) $(ALEX_OPTS) $< -o $@
 
+$(CABAL_BUILD)/Core/Parse.hs: $(SRC)/Core/Parse.y
+	$(HAPPY) $(HAPPY_OPTS) $< -o $@
+
+$(CABAL_BUILD)/Core/Lex.hs: $(SRC)/Core/Lex.x
+	$(ALEX) $(ALEX_OPTS) $< -o $@
+

rlp.cabal

@@ -12,6 +12,7 @@ category:           Language
 build-type:         Simple
 extra-doc-files:    README.md
 -- extra-source-files:
+tested-with:        GHC==9.6.2
 
 common warnings
 --    ghc-options: -Wall -Wno-incomplete-uni-patterns -Wno-unused-top-binds
@@ -72,6 +73,9 @@ library
     hs-source-dirs:   src
     default-language: GHC2021
 
+    default-extensions:
+        OverloadedStrings
+
 executable rlpc
     import:           warnings
     main-is:          Main.hs

src/Compiler/JustRun.hs

@@ -26,21 +26,23 @@ import Data.Function                    ((&))
 import GM
 ----------------------------------------------------------------------------------
 
-justLexSrc :: String -> Either RlpcError [CoreToken]
+justLexSrc :: String -> Either [MsgEnvelope RlpcError] [CoreToken]
 justLexSrc s = lexCoreR (T.pack s)
              & fmap (map $ \ (Located _ _ _ t) -> t)
              & rlpcToEither
 
-justParseSrc :: String -> Either RlpcError Program'
+justParseSrc :: String -> Either [MsgEnvelope RlpcError] Program'
 justParseSrc s = parse (T.pack s)
                & rlpcToEither
     where parse = lexCoreR >=> parseCoreProgR
 
-justTypeCheckSrc :: String -> Either RlpcError Program'
+justTypeCheckSrc :: String -> Either [MsgEnvelope RlpcError] Program'
 justTypeCheckSrc s = typechk (T.pack s)
                    & rlpcToEither
     where typechk = lexCoreR >=> parseCoreProgR >=> checkCoreProgR
 
-rlpcToEither :: RLPC e a -> Either e a
+rlpcToEither :: RLPC a -> Either [MsgEnvelope RlpcError] a
-rlpcToEither = evalRLPC def >>> fmap fst
+rlpcToEither r = case evalRLPC def r of
+    (Just a,   _) -> Right a
+    (Nothing, es) -> Left es
 

src/Compiler/RLPC.hs

@@ -16,9 +16,9 @@ module Compiler.RLPC
     , RLPCT(..)
     , RLPCIO
     , RLPCOptions(RLPCOptions)
-    , RlpcError(..)
     , IsRlpcError(..)
-    , rlpc
+    , RlpcError(..)
+    , MsgEnvelope(..)
     , addFatal
     , addWound
     , MonadErrorful
@@ -27,9 +27,6 @@ module Compiler.RLPC
     , evalRLPCT
     , evalRLPCIO
     , evalRLPC
-    , addRlpcWound
-    , addRlpcFatal
-    , liftRlpcErrs
     , rlpcLogFile
     , rlpcDebugOpts
     , rlpcEvaluator
@@ -40,6 +37,7 @@ module Compiler.RLPC
     , flagDDumpOpts
     , flagDDumpAST
     , def
+    , liftErrorful
     )
     where
 ----------------------------------------------------------------------------------
@@ -51,6 +49,7 @@ import Control.Monad.Errorful
 import Compiler.RlpcError
 import Data.Functor.Identity
 import Data.Default.Class
+import Data.Foldable
 import GHC.Generics             (Generic)
 import Data.Hashable            (Hashable)
 import Data.HashSet             (HashSet)
@@ -58,48 +57,44 @@ import Data.HashSet             qualified as S
 import Data.Coerce
 import Lens.Micro
 import Lens.Micro.TH
+import System.Exit
 ----------------------------------------------------------------------------------
 
--- TODO: fancy errors
+newtype RLPCT m a = RLPCT {
-newtype RLPCT e m a = RLPCT {
+        runRLPCT :: ReaderT RLPCOptions (ErrorfulT (MsgEnvelope RlpcError) m) a
-        runRLPCT :: ReaderT RLPCOptions (ErrorfulT e m) a
     }
-    -- TODO: incorrect ussage of MonadReader. RLPC should have its own
+    deriving (Functor, Applicative, Monad)
-    -- environment access functions
-    deriving (Functor, Applicative, Monad, MonadReader RLPCOptions)
 
-deriving instance (MonadIO m) => MonadIO (RLPCT e m)
+type RLPC = RLPCT Identity
 
-instance MonadTrans (RLPCT e) where
+type RLPCIO = RLPCT IO
-    lift = RLPCT . lift . lift
-
-instance (MonadState s m) => MonadState s (RLPCT e m) where
-    state = lift . state
-
-type RLPC e = RLPCT e Identity
-
-type RLPCIO e = RLPCT e IO
-
-evalRLPCT :: RLPCOptions
-          -> RLPCT e m a
-          -> m (Either e (a, [e]))
-evalRLPCT o = runRLPCT >>> flip runReaderT o >>> runErrorfulT
 
 evalRLPC :: RLPCOptions
-         -> RLPC e a
+         -> RLPC a
-         -> Either e (a, [e])
+         -> (Maybe a, [MsgEnvelope RlpcError])
-evalRLPC o m = coerce $ evalRLPCT o m
+evalRLPC opt r = runRLPCT r
+               & flip runReaderT opt
+               & runErrorful
 
-evalRLPCIO :: (Exception e)
+evalRLPCT :: (Monad m)
-           => RLPCOptions
+          => RLPCOptions
-           -> RLPCIO e a
+          -> RLPCT m a
-           -> IO (a, [e])
+          -> m (Maybe a, [MsgEnvelope RlpcError])
-evalRLPCIO o m = do
+evalRLPCT = undefined
-    m' <- evalRLPCT o m
+
-    case m' of
+evalRLPCIO :: RLPCOptions -> RLPCIO a -> IO a
-        -- TODO: errors
+evalRLPCIO opt r = do
-        Left e -> throwIO e
+    (ma,es) <- evalRLPCT opt r
-        Right a -> pure a
+    putRlpcErrs es
+    case ma of
+        Just x  -> pure x
+        Nothing -> die "Failed, no code compiled."
+
+putRlpcErrs :: [MsgEnvelope RlpcError] -> IO ()
+putRlpcErrs = traverse_ print
+
+liftErrorful :: (Monad m, IsRlpcError e) => ErrorfulT (MsgEnvelope e) m a -> RLPCT m a
+liftErrorful e = RLPCT $ lift (fmap liftRlpcError `mapErrorful` e)
 
 data RLPCOptions = RLPCOptions
     { _rlpcLogFile     :: Maybe FilePath
@@ -113,32 +108,6 @@ data RLPCOptions = RLPCOptions
 data Evaluator = EvaluatorGM | EvaluatorTI
     deriving Show
 
-data Severity = Error
-              | Warning
-              | Debug
-              deriving Show
-
--- temporary until we have a new doc building system
-type ErrorDoc = String
-
-instance (Monad m) => MonadErrorful e (RLPCT e m) where
-    addWound = RLPCT . lift . addWound
-    addFatal = RLPCT . lift . addFatal
-
-liftRlpcErrs :: (IsRlpcError e, Monad m)
-             => RLPCT e m a -> RLPCT RlpcError m a
-liftRlpcErrs m = RLPCT . ReaderT $ \r ->
-    mapErrors liftRlpcErr $ runRLPCT >>> (`runReaderT` r) $ m
-
-addRlpcWound :: (IsRlpcError e, Monad m) => e -> RLPCT RlpcError m ()
-addRlpcWound = addWound . liftRlpcErr
-
-addRlpcFatal :: (IsRlpcError e, Monad m) => e -> RLPCT RlpcError m ()
-addRlpcFatal = addWound . liftRlpcErr
-
-rlpc :: (Monad m) => ErrorfulT e m a -> RLPCT e m a
-rlpc = RLPCT . ReaderT . const
-
 ----------------------------------------------------------------------------------
 
 instance Default RLPCOptions where

src/Compiler/RlpcError.hs

@@ -1,15 +1,70 @@
+{-# LANGUAGE TemplateHaskell #-}
+{-# LANGUAGE PatternSynonyms, ViewPatterns #-}
 module Compiler.RlpcError
-    ( RlpcError(..)
+    ( IsRlpcError(..)
-    , IsRlpcError(..)
+    , MsgEnvelope(..)
+    , Severity(..)
+    , RlpcError(..)
+    , SrcSpan(..)
+    , msgSpan
+    , msgDiagnostic
+    , msgSeverity
+    , liftRlpcErrors
+    , errorMsg
     )
     where
 ----------------------------------------------------------------------------------
 import Control.Monad.Errorful
+import Data.Text                (Text)
+import Data.Text                qualified as T
+import GHC.Exts                 (IsString(..))
+import Lens.Micro.Platform
+import Lens.Micro.Platform.Internal
 ----------------------------------------------------------------------------------
 
-data RlpcError = RlpcErr String -- temp
+data MsgEnvelope e = MsgEnvelope
+   { _msgSpan        :: SrcSpan
+   , _msgDiagnostic  :: e
+   , _msgSeverity    :: Severity
+   }
+   deriving (Functor, Show)
+
+newtype RlpcError = Text [Text]
     deriving Show
 
-class IsRlpcError a where
+instance IsString RlpcError where
-    liftRlpcErr :: a -> RlpcError
+    fromString = Text . pure . T.pack
+
+class IsRlpcError e where
+    liftRlpcError :: e -> RlpcError
+
+instance IsRlpcError RlpcError where
+    liftRlpcError = id
+
+data Severity = SevWarning
+              | SevError
+              deriving Show
+
+data SrcSpan = SrcSpan
+    !Int -- ^ Line
+    !Int -- ^ Column
+    !Int -- ^ Length
+    deriving Show
+
+makeLenses ''MsgEnvelope
+
+liftRlpcErrors :: (Functor m, IsRlpcError e)
+               => ErrorfulT e m a
+               -> ErrorfulT RlpcError m a
+liftRlpcErrors = mapErrorful liftRlpcError
+
+instance (IsRlpcError e) => IsRlpcError (MsgEnvelope e) where
+    liftRlpcError msg = msg ^. msgDiagnostic & liftRlpcError
+
+errorMsg :: SrcSpan -> e -> MsgEnvelope e
+errorMsg s e = MsgEnvelope
+    { _msgSpan = s
+    , _msgDiagnostic = e
+    , _msgSeverity = SevError
+    }
 

src/Control/Monad/Errorful.hs

@@ -1,73 +1,79 @@
 {-# LANGUAGE StandaloneDeriving #-}
 {-# LANGUAGE FunctionalDependencies #-}
 {-# LANGUAGE TupleSections, PatternSynonyms #-}
+{-# LANGUAGE UndecidableInstances #-}
 module Control.Monad.Errorful
     ( ErrorfulT
     , runErrorfulT
     , Errorful
     , runErrorful
-    , mapErrors
+    , mapErrorful
     , MonadErrorful(..)
     )
     where
 ----------------------------------------------------------------------------------
+import Control.Monad.State.Strict
 import Control.Monad.Trans
 import Data.Functor.Identity
 import Data.Coerce
+import Data.HashSet                 (HashSet)
+import Data.HashSet                 qualified as H
 import Lens.Micro
 ----------------------------------------------------------------------------------
 
-newtype ErrorfulT e m a = ErrorfulT { runErrorfulT :: m (Either e (a, [e])) }
+newtype ErrorfulT e m a = ErrorfulT { runErrorfulT :: m (Maybe a, [e]) }
 
 type Errorful e = ErrorfulT e Identity
 
-pattern Errorful :: (Either e (a, [e])) -> Errorful e a
+pattern Errorful :: (Maybe a, [e]) -> Errorful e a
 pattern Errorful a = ErrorfulT (Identity a)
 
-runErrorful :: Errorful e a -> Either e (a, [e])
+runErrorful :: Errorful e a -> (Maybe a, [e])
 runErrorful m = coerce (runErrorfulT m)
 
 class (Applicative m) => MonadErrorful e m | m -> e where
-    addWound   :: e -> m ()
+    addWound :: e -> m ()
-    addFatal   :: e -> m a
+    addFatal :: e -> m a
-
-    -- not sure if i want to add this yet...
-    -- catchWound :: m a -> (e -> m a) -> m a
 
 instance (Applicative m) => MonadErrorful e (ErrorfulT e m) where
-    addWound e = ErrorfulT $ pure . Right $ ((), [e])
+    addWound e = ErrorfulT $ pure (Just (), [e])
-    addFatal e = ErrorfulT $ pure . Left  $ e
+    addFatal e = ErrorfulT $ pure (Nothing, [e])
 
 instance MonadTrans (ErrorfulT e) where
-    lift m = ErrorfulT (Right . (,[]) <$> m)
+    lift m = ErrorfulT ((\x -> (Just x,[])) <$> m)
 
 instance (MonadIO m) => MonadIO (ErrorfulT e m) where
     liftIO = lift . liftIO
 
 instance (Functor m) => Functor (ErrorfulT e m) where
-    fmap f (ErrorfulT m) = ErrorfulT $ fmap (_1 %~ f) <$> m
+    fmap f (ErrorfulT m) = ErrorfulT (m & mapped . _1 . _Just %~ f)
 
 instance (Applicative m) => Applicative (ErrorfulT e m) where
-    pure a = ErrorfulT (pure . Right $ (a, []))
+    pure a = ErrorfulT . pure $ (Just a, [])
 
-    m <*> a = ErrorfulT (m' `apply` a')
+    ErrorfulT m <*> ErrorfulT n = ErrorfulT $ m `apply` n where
-        where
+        apply :: m (Maybe (a -> b), [e]) -> m (Maybe a, [e]) -> m (Maybe b, [e])
-            m' = runErrorfulT m
+        apply = liftA2 $ \ (mf,e1) (ma,e2) -> (mf <*> ma, e1 <> e2)
-            a' = runErrorfulT a
-            -- TODO: strict concatenation
-            apply = liftA2 $ liftA2 (\ (f,e1) (x,e2) -> (f x, e1 ++ e2)) 
 
 instance (Monad m) => Monad (ErrorfulT e m) where
     ErrorfulT m >>= k = ErrorfulT $ do
-        m' <- m
+        (a,es) <- m
-        case m' of
+        case a of
-            Right (a,es) -> runErrorfulT (k a)
+            Just x      -> runErrorfulT (k x)
-            Left e       -> pure (Left e)
+            Nothing     -> pure (Nothing, es)
 
-mapErrors :: (Monad m) => (e -> e') -> ErrorfulT e m a -> ErrorfulT e' m a
+mapErrorful :: (Functor m) => (e -> e') -> ErrorfulT e m a -> ErrorfulT e' m a
-mapErrors f m = ErrorfulT $ do
+mapErrorful f (ErrorfulT m) = ErrorfulT $
-    x <- runErrorfulT m
+    m & mapped . _2 . mapped %~ f
-    case x of
+
-        Left  e      -> pure . Left  $ f e
+-- when microlens-pro drops we can write this as
-        Right (a,es) -> pure . Right $ (a, f <$> es)
+--    mapErrorful f = coerced . mapped . _2 . mappd %~ f
+-- lol
+
+--------------------------------------------------------------------------------
+-- daily dose of n^2 instances
+
+instance (Monad m, MonadErrorful e m) => MonadErrorful e (StateT s m) where
+    addWound = undefined
+    addFatal = undefined
 

src/Core/Examples.hs

@@ -15,6 +15,13 @@ import Core.Syntax
 import Core.TH
 ----------------------------------------------------------------------------------
 
+-- fac3 = undefined
+-- sumList = undefined
+-- constDivZero = undefined
+-- idCase = undefined
+
+---
+
 letrecExample :: Program'
 letrecExample = [coreProg|
     pair x y f = f x y;
@@ -216,3 +223,4 @@ idCase = [coreProg|
 --         , ScDef "Cons" [] $ Con 2 2
 --         ]
 
+--}

src/Core/HindleyMilner.hs

@@ -3,6 +3,7 @@ Module      : Core.HindleyMilner
 Description : Hindley-Milner type system
 -}
 {-# LANGUAGE LambdaCase #-}
+{-# LANGUAGE OverloadedStrings #-}
 module Core.HindleyMilner
     ( Context'
     , infer
@@ -16,15 +17,17 @@ module Core.HindleyMilner
 ----------------------------------------------------------------------------------
 import Lens.Micro
 import Lens.Micro.Mtl
+import Lens.Micro.Platform
 import Data.Maybe               (fromMaybe)
 import Data.Text                qualified as T
 import Data.HashMap.Strict      qualified as H
 import Data.Foldable            (traverse_)
 import Compiler.RLPC
-import Control.Monad            (foldM, void)
+import Control.Monad            (foldM, void, forM)
 import Control.Monad.Errorful   (Errorful, addFatal)
 import Control.Monad.State
 import Control.Monad.Utils      (mapAccumLM)
+import Text.Printf
 import Core.Syntax
 ----------------------------------------------------------------------------------
 
@@ -48,9 +51,20 @@ data TypeError
     | TyErrMissingTypeSig Name
     deriving (Show, Eq)
 
--- TODO:
 instance IsRlpcError TypeError where
-    liftRlpcErr = RlpcErr . show
+    liftRlpcError = \case
+        -- todo: use anti-parser instead of show
+        TyErrCouldNotUnify t u -> Text
+            [ T.pack $ printf "Could not match type `%s' with `%s'."
+                              (show t) (show u)
+            , "Expected: " <> tshow t
+            , "Got: " <> tshow u
+            ]
+        TyErrRecursiveType t x -> Text
+            [ T.pack $ printf "recursive type error lol"
+            ]
+
+        where tshow = T.pack . show
 
 -- | Synonym for @Errorful [TypeError]@. This means an @HMError@ action may
 -- throw any number of fatal or nonfatal errors. Run with @runErrorful@.
@@ -88,10 +102,10 @@ checkCoreProg p = scDefs
              where scname = sc ^. _lhs._1
 
 -- | @checkCoreProgR p@ returns @p@ if @p@ successfully typechecks.
-checkCoreProgR :: Program' -> RLPC RlpcError Program'
+checkCoreProgR :: Program' -> RLPC Program'
-checkCoreProgR p = do
+checkCoreProgR p = undefined
-    liftRlpcErrs . rlpc . checkCoreProg $ p
+
-    pure p
+{-# WARNING checkCoreProgR "unimpl" #-}
 
 -- | Infer the type of an expression under some context.
 --
@@ -140,7 +154,27 @@ gather = \g e -> runStateT (go g e) ([],0) <&> \ (t,(cs,_)) -> (t,cs) where
         Let NonRec bs e -> do
             g' <- buildLetContext g bs
             go g' e
-        -- TODO letrec, lambda, case
+        Let Rec bs e -> do
+            g' <- buildLetrecContext g bs
+            go g' e
+
+        -- TODO lambda, case
+
+    buildLetrecContext :: Context' -> [Binding']
+                       -> StateT ([Constraint], Int) HMError Context'
+    buildLetrecContext g bs = do
+        let f ag (k := _) = do
+                n <- uniqueVar
+                pure ((k,n) : ag)
+        rg <- foldM f g bs
+        let k ag (k := v) = do
+                t <- go rg v
+                pure ((k,t) : ag)
+        foldM k g bs
+
+    -- | augment a context with the inferred types of each binder. the returned
+    -- context is linearly accumulated, meaning that the context used to infer each binder
+    -- will include the inferred types of all previous binder
 
     buildLetContext :: Context' -> [Binding']
                     -> StateT ([Constraint], Int) HMError Context'
@@ -218,3 +252,20 @@ subst x t (TyVar y) | x == y  = t
 subst x t (a :-> b)           = subst x t a :-> subst x t b
 subst _ _ e                   = e
 
+--------------------------------------------------------------------------------
+
+demoContext :: Context'
+demoContext =
+    [ ("fix", (TyVar "a" :-> TyVar "a") :-> TyVar "a")
+    , ("add", TyInt :-> TyInt :-> TyInt)
+    , ("==", TyInt :-> TyInt :-> TyCon "Bool")
+    , ("True", TyCon "Bool")
+    , ("False", TyCon "Bool")
+    ]
+
+pprintType :: Type -> String
+pprintType (s :-> t) = "(" <> pprintType s <> " -> " <> pprintType t <> ")"
+pprintType TyFun = "(->)"
+pprintType (TyVar x) = x ^. unpacked
+pprintType (TyCon t) = t ^. unpacked
+

src/Core/Lex.x

@@ -167,24 +167,19 @@ lexWith :: (Text -> CoreToken) -> Lexer
 lexWith f (AlexPn _ y x,_,_,s) l = pure $ Located y x l (f $ T.take l s)
 
 -- | The main lexer driver.
-lexCore :: Text -> RLPC SrcError [Located CoreToken]
+lexCore :: Text -> RLPC [Located CoreToken]
 lexCore s = case m of
-    Left e   -> addFatal err
+    Left e   -> error "core lex error"
-        where err = SrcError
-                { _errSpan       = (0,0,0) -- TODO: location
-                , _errSeverity   = Error
-                , _errDiagnostic = SrcErrLexical e
-                }
     Right ts -> pure ts
     where
         m = runAlex s lexStream
 
-lexCoreR :: Text -> RLPC RlpcError [Located CoreToken]
+lexCoreR :: Text -> RLPC [Located CoreToken]
-lexCoreR = liftRlpcErrs . lexCore
+lexCoreR = lexCore
 
 -- | @lexCore@, but the tokens are stripped of location info. Useful for
 -- debugging
-lexCore' :: Text -> RLPC SrcError [CoreToken]
+lexCore' :: Text -> RLPC [CoreToken]
 lexCore' s = fmap f <$> lexCore s
     where f (Located _ _ _ t) = t
 
@@ -201,11 +196,11 @@ data ParseError = ParErrLexical String
 
 -- TODO:
 instance IsRlpcError SrcError where
-    liftRlpcErr = RlpcErr . show
+    liftRlpcError = Text . pure . T.pack . show
 
 -- TODO:
 instance IsRlpcError ParseError where
-    liftRlpcErr = RlpcErr . show
+    liftRlpcError = Text . pure . T.pack . show
 
 alexEOF :: Alex (Located CoreToken)
 alexEOF = Alex $ \ st@(AlexState { alex_pos = AlexPn _ y x }) ->

src/Core/Parse.y

@@ -10,7 +10,6 @@ module Core.Parse
     , parseCoreProg
     , parseCoreProgR
     , module Core.Lex -- temp convenience
-    , parseTmp
     , SrcError
     , Module
     )
@@ -34,7 +33,7 @@ import Data.HashMap.Strict  qualified as H
 %name parseCoreProg StandaloneProgram
 %tokentype { Located CoreToken }
 %error { parseError }
-%monad { RLPC SrcError }
+%monad { RLPC } { happyBind } { happyPure }
 
 %token
       let             { Located _ _ _ TokenLet }
@@ -99,6 +98,8 @@ ScDefs          : ScDef ';' ScDefs              { $1 : $3 }
 
 ScDef           :: { ScDef Name }
 ScDef           : Var ParList '=' Expr          { ScDef $1 $2 $4 }
+                -- hack to allow constructors to be compiled into scs
+                | Con ParList '=' Expr          { ScDef $1 $2 $4 }
 
 Type            :: { Type }
 Type            : Type1                         { $1 }
@@ -189,34 +190,23 @@ Con             : '(' consym ')'                    { $2 }
 
 {
 
-parseError :: [Located CoreToken] -> RLPC SrcError a
+parseError :: [Located CoreToken] -> RLPC a
-parseError (Located y x l _ : _) = addFatal err
+parseError (Located y x l t : _) =
-    where err = SrcError
+    error $ show y <> ":" <> show x
-            { _errSpan       = (y,x,l)
+         <> ": parse error at token `" <> show t <> "'"
-            , _errSeverity   = Error
-            , _errDiagnostic = SrcErrParse
-            }
 
-parseTmp :: IO (Module Name)
+{-# WARNING parseError "unimpl" #-}
-parseTmp = do
-    s <- TIO.readFile "/tmp/t.hs"
-    case parse s of
-        Left e -> error (show e)
-        Right (ts,_) -> pure ts
-    where
-        parse = evalRLPC def . (lexCore >=> parseCore)
 
-exprPragma :: [String] -> RLPC SrcError (Expr Name)
+exprPragma :: [String] -> RLPC (Expr Name)
-exprPragma ("AST" : e) = astPragma e
+exprPragma ("AST" : e) = undefined
-exprPragma _           = addFatal err
+exprPragma _           = undefined
-    where err = SrcError
-            { _errSpan       = (0,0,0) -- TODO: span
-            , _errSeverity   = Warning
-            , _errDiagnostic = SrcErrUnknownPragma "" -- TODO: missing pragma
-            }
 
-astPragma :: [String] -> RLPC SrcError (Expr Name)
+{-# WARNING exprPragma "unimpl" #-}
-astPragma = pure . read . unwords
+
+astPragma :: [String] -> RLPC (Expr Name)
+astPragma _ = undefined
+
+{-# WARNING astPragma "unimpl" #-}
 
 insTypeSig :: (Hashable b) => (b, Type) -> Program b -> Program b
 insTypeSig ts = programTypeSigs %~ uncurry H.insert ts
@@ -230,8 +220,14 @@ insScDef sc = programScDefs %~ (sc:)
 singletonScDef :: (Hashable b) => ScDef b -> Program b
 singletonScDef sc = insScDef sc mempty
 
-parseCoreProgR :: [Located CoreToken] -> RLPC RlpcError Program'
+parseCoreProgR :: [Located CoreToken] -> RLPC Program'
-parseCoreProgR = liftRlpcErrs . parseCoreProg
+parseCoreProgR = parseCoreProg
+
+happyBind :: RLPC a -> (a -> RLPC b) -> RLPC b
+happyBind m k = m >>= k
+
+happyPure :: a -> RLPC a
+happyPure a = pure a
 
 }
 

src/Core/TH.hs

@@ -6,7 +6,6 @@ module Core.TH
     ( coreExpr
     , coreProg
     , coreProgT
-    , core
     )
     where
 ----------------------------------------------------------------------------------
@@ -14,74 +13,38 @@ import Language.Haskell.TH
 import Language.Haskell.TH.Syntax   hiding (Module)
 import Language.Haskell.TH.Quote
 import Control.Monad                ((>=>))
+import Control.Monad.IO.Class
+import Control.Arrow                ((>>>))
 import Compiler.RLPC
 import Data.Default.Class           (def)
+import Data.Text                    (Text)
 import Data.Text                    qualified as T
 import Core.Parse
 import Core.Lex
+import Core.Syntax
 import Core.HindleyMilner           (checkCoreProgR)
 ----------------------------------------------------------------------------------
 
--- TODO: write in terms of a String -> QuasiQuoter
-
-core :: QuasiQuoter
-core = QuasiQuoter
-    { quoteExp = qCore
-    , quotePat = error "core quasiquotes may only be used in expressions"
-    , quoteType = error "core quasiquotes may only be used in expressions"
-    , quoteDec = error "core quasiquotes may only be used in expressions"
-    }
-
 coreProg :: QuasiQuoter
-coreProg = QuasiQuoter
+coreProg = mkqq $ lexCoreR >=> parseCoreProgR
-    { quoteExp = qCoreProg
-    , quotePat = error "core quasiquotes may only be used in expressions"
-    , quoteType = error "core quasiquotes may only be used in expressions"
-    , quoteDec = error "core quasiquotes may only be used in expressions"
-    }
 
 coreExpr :: QuasiQuoter
-coreExpr = QuasiQuoter
+coreExpr = mkqq $ lexCoreR >=> parseCoreExpr
-    { quoteExp = qCoreExpr
-    , quotePat = error "core quasiquotes may only be used in expressions"
-    , quoteType = error "core quasiquotes may only be used in expressions"
-    , quoteDec = error "core quasiquotes may only be used in expressions"
-    }
 
 -- | Type-checked @coreProg@
 coreProgT :: QuasiQuoter
-coreProgT = QuasiQuoter
+coreProgT = mkqq $ lexCoreR >=> parseCoreProgR >=> checkCoreProgR
-    { quoteExp = qCoreProgT
+
+mkqq :: (Lift a) => (Text -> RLPC a) -> QuasiQuoter
+mkqq p = QuasiQuoter
+    { quoteExp = mkq p
     , quotePat = error "core quasiquotes may only be used in expressions"
     , quoteType = error "core quasiquotes may only be used in expressions"
     , quoteDec = error "core quasiquotes may only be used in expressions"
     }
 
-qCore :: String -> Q Exp
+mkq :: (Lift a) => (Text -> RLPC a) -> String -> Q Exp
-qCore s = case parse (T.pack s) of
+mkq parse s = case evalRLPC def (parse $ T.pack s) of
-    Left e       -> error (show e)
+    (Just a,  _) -> lift a
-    Right (m,ts) -> lift m
+    (Nothing, _) -> error "todo: aaahhbbhjhbdjhabsjh"
-    where
-        parse = evalRLPC def . (lexCore >=> parseCore)
-
-qCoreExpr :: String -> Q Exp
-qCoreExpr s = case parseExpr (T.pack s) of
-    Left e       -> error (show e)
-    Right (m,ts) -> lift m
-    where
-        parseExpr = evalRLPC def . (lexCore >=> parseCoreExpr)
-
-qCoreProg :: String -> Q Exp
-qCoreProg s = case parse (T.pack s) of
-    Left e       -> error (show e)
-    Right (m,ts) -> lift m
-    where
-        parse = evalRLPC def . (lexCoreR >=> parseCoreProgR)
-
-qCoreProgT :: String -> Q Exp
-qCoreProgT s = case parse (T.pack s) of
-    Left e      -> error (show e)
-    Right (m,_) -> lift m
-    where
-        parse = evalRLPC def . (lexCoreR >=> parseCoreProgR >=> checkCoreProgR)
 

src/Rlp/Lex.x

@@ -7,12 +7,14 @@ module Rlp.Lex
     , RlpToken(..)
     , Located(..)
     , lexToken
+    , lexStream
     , lexDebug
     , lexCont
     )
     where
 import Codec.Binary.UTF8.String (encodeChar)
 import Control.Monad
+import Control.Monad.Errorful
 import Core.Syntax              (Name)
 import Data.Functor.Identity
 import Data.Char                (digitToInt)
@@ -52,6 +54,7 @@ $asciisym       = [\!\#\$\%\&\*\+\.\/\<\=\>\?\@\\\^\|\-\~\:]
 
 @reservedname = 
     case|data|do|import|in|let|letrec|module|of|where
+    |infixr|infixl|infix
 
 @reservedop =
     "=" | \\ | "->" | "|"
@@ -90,6 +93,8 @@ $white_no_nl+       ;
 -- control characters
 <0>
 {
+    "("                 { constToken TokenLParen }
+    ")"                 { constToken TokenRParen }
     "{"                 { explicitLBrace }
     "}"                 { explicitRBrace }
     ";"                 { constToken TokenSemicolon }
@@ -121,6 +126,9 @@ lexReservedName = \case
     "of"        -> TokenOf
     "let"       -> TokenLet
     "in"        -> TokenIn
+    "infix"     -> TokenInfix
+    "infixl"    -> TokenInfixL
+    "infixr"    -> TokenInfixR
 
 lexReservedOp :: Text -> RlpToken
 lexReservedOp = \case
@@ -201,13 +209,6 @@ alexEOF = do
     inp <- getInput
     pure (Located undefined TokenEOF)
 
-execP :: P a -> ParseState -> Maybe a
-execP p st = runP p st & snd
-
-execP' :: P a -> Text -> Maybe a
-execP' p s = execP p st where
-    st = initParseState s
-
 initParseState :: Text -> ParseState
 initParseState s = ParseState
     { _psLayoutStack = []
@@ -226,6 +227,10 @@ initAlexInput s = AlexInput
     , _aiPos        = (1,1)
     }
 
+runP' :: P a -> Text -> (ParseState, [MsgEnvelope RlpParseError], Maybe a)
+runP' p s = runP p st where
+    st = initParseState s
+
 lexToken :: P (Located RlpToken)
 lexToken = do
     inp <- getInput
@@ -240,6 +245,7 @@ lexToken = do
         AlexToken inp' l act -> do
             psInput .= inp'
             act inp l
+        AlexError inp' -> addFatalHere 1 RlpParErrLexical
 
 lexCont :: (Located RlpToken -> P a) -> P a
 lexCont = (lexToken >>=)
@@ -258,7 +264,7 @@ lexDebug k = do
     k t
 
 lexTest :: Text -> Maybe [RlpToken]
-lexTest s = execP' lexStream s
+lexTest s = runP' lexStream s ^. _3
 
 indentLevel :: P Int
 indentLevel = do

src/Rlp/Parse.y

@@ -1,28 +1,35 @@
 {
+{-# LANGUAGE LambdaCase #-}
 module Rlp.Parse
-    ( parseRlpProgram
+    ( parseRlpProg
     )
     where
+import Compiler.RlpcError
 import Rlp.Lex
 import Rlp.Syntax
 import Rlp.Parse.Types
 import Rlp.Parse.Associate
+import Lens.Micro
 import Lens.Micro.Mtl
+import Lens.Micro.Platform          ()
 import Data.List.Extra
 import Data.Fix
 import Data.Functor.Const
+import Data.Text                    qualified as T
 }
 
-%name parseRlpProgram StandaloneProgram
+%name parseRlpProg StandaloneProgram
 
 %monad { P }
-%lexer { lexDebug } { Located _ TokenEOF }
+%lexer { lexCont } { Located _ TokenEOF }
 %error { parseError }
 %tokentype { Located RlpToken }
 
 %token
     varname         { Located _ (TokenVarName $$) }
     conname         { Located _ (TokenConName $$) }
+    consym          { Located _ (TokenConSym $$) }
+    varsym          { Located _ (TokenVarSym $$) }
     data            { Located _ TokenData }
     litint          { Located _ (TokenLitInt $$) }
     '='             { Located _ TokenEquals }
@@ -36,6 +43,9 @@ import Data.Functor.Const
     '}'             { Located _ TokenRBrace }
     vlbrace         { Located _ TokenLBraceV }
     vrbrace         { Located _ TokenRBraceV }
+    infixl          { Located _ TokenInfixL }
+    infixr          { Located _ TokenInfixR }
+    infix           { Located _ TokenInfix }
 
 %right '->'
 
@@ -67,8 +77,17 @@ VS                  : ';'                   { $1 }
                     | vsemi                 { $1 }
 
 Decl        :: { PartialDecl' }
-Decl        : FunDecl                   { $1 }
+            : FunDecl                   { $1 }
             | DataDecl                  { $1 }
+            | InfixDecl                 { $1 }
+
+InfixDecl   :: { PartialDecl' }
+            : InfixWord litint InfixOp  {% mkInfixD $1 $2 $3 }
+
+InfixWord   :: { Assoc }
+            : infixl                    { InfixL }
+            | infixr                    { InfixR }
+            | infix                     { Infix  }
 
 DataDecl    :: { PartialDecl' }
             : data Con TyParams '=' DataCons    { DataD $2 $3 $5 }
@@ -109,9 +128,24 @@ Pat1        :: { Pat' }
             | Lit                       { LitP $1 }
 
 Expr        :: { PartialExpr' }
-Expr        : Lit                       { Fix . E $ LitEF $1 }
+            : Expr1 varsym Expr         { Fix $ B $2 (unFix $1) (unFix $3) }
+            | Expr1                     { $1 }
+
+Expr1       :: { PartialExpr' }
+            : '(' Expr ')'              { wrapFix . Par . unwrapFix $ $2 }
+            | Lit                       { Fix . E $ LitEF $1 }
             | Var                       { Fix . E $ VarEF $1 }
 
+-- TODO: happy prefers left-associativity. doing such would require adjusting
+-- the code in Rlp.Parse.Associate to expect left-associative input rather than
+-- right.
+InfixExpr   :: { PartialExpr' }
+            : Expr1 varsym Expr         { Fix $ B $2 (unFix $1) (unFix $3) }
+
+InfixOp     :: { Name }
+            : consym                    { $1 }
+            | varsym                    { $1 }
+
 Lit         :: { Lit' }
 Lit         : litint                    { IntL $1 }
 
@@ -129,6 +163,19 @@ mkProgram ds = do
     pure $ RlpProgram (associate pt <$> ds)
 
 parseError :: Located RlpToken -> P a
-parseError = error . show
+parseError (Located ((l,c),s) t) = addFatal $
+    errorMsg (SrcSpan l c s) RlpParErrUnexpectedToken
+
+mkInfixD :: Assoc -> Int -> Name -> P PartialDecl'
+mkInfixD a p n = do
+    let opl :: Lens' ParseState (Maybe OpInfo)
+        opl = psOpTable . at n
+    opl <~ (use opl >>= \case
+        Just o  -> addWoundHere l e >> pure (Just o) where
+            e = RlpParErrDuplicateInfixD n
+            l = T.length n
+        Nothing -> pure (Just (a,p))
+        )
+    pure $ InfixD a p n
 
 }

src/Rlp/Parse/Associate.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE PatternSynonyms, ViewPatterns, ImplicitParams #-}
 module Rlp.Parse.Associate
     ( associate

src/Rlp/Parse/Types.hs

@@ -1,11 +1,47 @@
 {-# LANGUAGE TemplateHaskell #-}
 {-# LANGUAGE ImplicitParams, ViewPatterns, PatternSynonyms #-}
 {-# LANGUAGE LambdaCase #-}
-module Rlp.Parse.Types where
+module Rlp.Parse.Types
+    ( LexerAction
+    , MsgEnvelope(..)
+    , RlpcError(..)
+    , AlexInput(..)
+    , Position(..)
+    , RlpToken(..)
+    , P(..)
+    , ParseState(..)
+    , psLayoutStack
+    , psLexState
+    , psInput
+    , psOpTable
+    , Layout(..)
+    , Located(..)
+    , OpTable
+    , OpInfo
+    , RlpParseError(..)
+    , PartialDecl'
+    , Partial(..)
+    , pL, pR
+    , PartialE
+    , pattern WithInfo
+    , opInfoOrDef
+    , PartialExpr'
+    , aiPrevChar
+    , aiSource
+    , aiBytes
+    , aiPos
+    , addFatal
+    , addWound
+    , addFatalHere
+    , addWoundHere
+    )
+    where
 --------------------------------------------------------------------------------
 import Core.Syntax                  (Name)
 import Control.Monad
-import Control.Monad.State.Class
+import Control.Monad.State.Strict
+import Control.Monad.Errorful
+import Compiler.RlpcError
 import Data.Text                    (Text)
 import Data.Maybe
 import Data.Fix
@@ -34,6 +70,12 @@ type Position =
     , Int -- column
     )
 
+posLine :: Lens' Position Int
+posLine = _1
+
+posColumn :: Lens' Position Int
+posColumn = _2
+
 data RlpToken
     -- literals
     = TokenLitInt Int
@@ -48,6 +90,9 @@ data RlpToken
     | TokenOf
     | TokenLet
     | TokenIn
+    | TokenInfixL
+    | TokenInfixR
+    | TokenInfix
     -- reserved ops
     | TokenArrow
     | TokenPipe
@@ -68,24 +113,34 @@ data RlpToken
     | TokenEOF
     deriving (Show)
 
-newtype P a = P { runP :: ParseState -> (ParseState, Maybe a) }
+newtype P a = P {
+        runP :: ParseState
+             -> (ParseState, [MsgEnvelope RlpParseError], Maybe a)
+    }
     deriving (Functor)
 
 instance Applicative P where
-    pure a = P $ \st -> (st,Just a)
+    pure a = P $ \st -> (st, [], pure a)
     liftA2 = liftM2
 
 instance Monad P where
     p >>= k = P $ \st ->
-        let (st',a) = runP p st
+        let (st',es,ma) = runP p st
-        in case a of
+        in case ma of
-            Just x  -> runP (k x) st'
+            Just a  -> runP (k a) st'
-            Nothing -> (st', Nothing)
+                     & _2 %~ (es<>)
+            Nothing -> (st',es,Nothing)
+
+    {-# INLINE (>>=) #-}
 
 instance MonadState ParseState P where
     state f = P $ \st ->
         let (a,st') = f st
-        in (st', Just a)
+        in (st', [], Just a)
+
+instance MonadErrorful (MsgEnvelope RlpParseError) P where
+    addWound e = P $ \st -> (st, [e], Just ())
+    addFatal e = P $ \st -> (st, [e], Nothing)
 
 data ParseState = ParseState
     { _psLayoutStack        :: [Layout]
@@ -108,11 +163,14 @@ type OpInfo = (Assoc, Int)
 -- data WithLocation a = WithLocation [String] a
 
 data RlpParseError = RlpParErrOutOfBoundsPrecedence Int
-                   | RlpParErrDuplicateInfixD
+                   | RlpParErrDuplicateInfixD Name
-    deriving (Eq, Ord, Show)
+                   | RlpParErrLexical
+                   | RlpParErrUnexpectedToken
+                   deriving (Eq, Ord, Show)
+
+instance IsRlpcError RlpParseError where
 
 ----------------------------------------------------------------------------------
-
 -- absolute psycho shit (partial ASTs)
 
 type PartialDecl' = Decl (Const PartialExpr') Name
@@ -158,3 +216,27 @@ type PartialExpr' = Fix Partial
 makeLenses ''AlexInput
 makeLenses ''ParseState
 
+addWoundHere :: Int -> RlpParseError -> P ()
+addWoundHere l e = P $ \st ->
+    let e' = MsgEnvelope
+            { _msgSpan = let pos = psInput . aiPos
+                         in SrcSpan (st ^. pos . posLine)
+                                   (st ^. pos . posColumn)
+                                   l
+            , _msgDiagnostic = e
+            , _msgSeverity = SevError
+            }
+    in (st, [e'], Just ())
+
+addFatalHere :: Int -> RlpParseError -> P a
+addFatalHere l e = P $ \st ->
+    let e' = MsgEnvelope
+            { _msgSpan = let pos = psInput . aiPos
+                         in SrcSpan (st ^. pos . posLine)
+                                    (st ^. pos . posColumn)
+                                    l
+            , _msgDiagnostic = e
+            , _msgSeverity = SevError
+            }
+    in (st, [e'], Nothing)
+

tst/Core/HindleyMilnerSpec.hs

@@ -38,9 +38,13 @@ spec = do
         let e = [coreExpr|3|]
         in check' [] (TyCon "Bool") e `shouldSatisfy` isLeft
 
-infer' :: Context' -> Expr' -> Either TypeError Type
+infer' :: Context' -> Expr' -> Either [TypeError] Type
-infer' g e = fmap fst . runErrorful $ infer g e
+infer' g e = case runErrorful $ infer g e of
+    (Just t,   _) -> Right t
+    (Nothing, es) -> Left es
 
-check' :: Context' -> Type -> Expr' -> Either TypeError ()
+check' :: Context' -> Type -> Expr' -> Either [TypeError] ()
-check' g t e = fmap fst . runErrorful $ check g t e
+check' g t e = case runErrorful $ check g t e of
+    (Just t,   _) -> Right ()
+    (Nothing, es) -> Left es