quox/src/Quox/Error.idr

336 lines
8.2 KiB
Idris
Raw Normal View History

2021-09-20 03:32:02 -04:00
module Quox.Error
import Control.Monad.Identity
import Control.Monad.Trans
import Control.Monad.Reader
import Control.Monad.Writer
import Control.Monad.State
import Control.Monad.RWS
%default total
public export
data Elem : a -> List a -> Type where
Here : x `Elem` (x :: xs)
There : x `Elem` xs -> x `Elem` (y :: xs)
%builtin Natural Elem
export
Uninhabited (x `Elem` []) where
uninhabited Here impossible
uninhabited (There _) impossible
public export
data Spine : List a -> Type where
NIL : Spine []
CONS : Spine xs -> Spine (x :: xs)
%builtin Natural Spine
public export
record OneOf types where
constructor One
elem : type `Elem` types
1 value : type
export
Uninhabited (OneOf []) where uninhabited x = uninhabited x.elem
export %inline
inj : ty `Elem` tys => ty -> OneOf tys
inj value = One %search value
public export
All : (Type -> Type) -> List Type -> Type
All p [] = ()
All p (x::xs) = (p x, All p xs)
private
eq : All Eq types => OneOf types -> OneOf types -> Bool
eq (One Here x) (One Here y) = x == y
eq (One (There p) x) (One (There q) y) = eq (One p x) (One q y)
eq (One Here _) (One (There _) _) = False
eq (One (There z) x) (One Here y) = False
export
All Eq types => Eq (OneOf types) where (==) = eq
private
ordsToEqs : Spine types => All Ord types => All Eq types
ordsToEqs @{NIL} = ()
ordsToEqs @{CONS tl} = (%search, ordsToEqs @{tl})
private
[eqOrds] (Spine types, All Ord types) => Eq (OneOf types) where
(==) = eq @{ordsToEqs}
private
cmp : All Ord types => OneOf types -> OneOf types -> Ordering
cmp (One Here x) (One Here y) = compare x y
cmp (One Here _) (One (There _) _) = LT
cmp (One (There _) _) (One Here _) = GT
cmp (One (There p) x) (One (There q) y) = cmp (One p x) (One q y)
export
(Spine types, All Ord types) => Ord (OneOf types) using eqOrds where
compare = cmp
export
All Show types => Show (OneOf types) where
showPrec d (One Here value) = showPrec d value
showPrec d (One (There p) value) = showPrec d $ One p value
public export
record ErrorT (errs : List Type) (m : Type -> Type) (res : Type) where
constructor MkErrorT
runErrorT : m (Either (OneOf errs) res)
public export
Error : List Type -> Type -> Type
Error errs = ErrorT errs Identity
export
runError : Error errs a -> Either (OneOf errs) a
runError = runIdentity . runErrorT
export %inline
Functor m => Functor (ErrorT errs m) where
map f (MkErrorT act) = MkErrorT $ map (map f) act
export %inline
Applicative m => Applicative (ErrorT errs m) where
pure = MkErrorT . pure . pure
MkErrorT mf <*> MkErrorT mx = MkErrorT [|mf <*> mx|]
export %inline
Monad m => Monad (ErrorT errs m) where
MkErrorT act >>= k = MkErrorT $ act >>= either (pure . Left) (runErrorT . k)
private
without' : (xs : List a) -> x `Elem` xs -> List a
without' (_ :: xs) Here = xs
without' (y :: xs) (There p) = y :: without' xs p
infix 9 `without`
export %inline
without : (xs : List a) -> (x : a) -> x `Elem` xs => List a
xs `without` x = without' {x} xs %search
private
get' : err `Elem` errs -> OneOf errs -> Either err (OneOf (errs `without` err))
get' Here (One Here x) = Left x
get' Here (One (There p) x) = Right (One p x)
get' (There y) (One Here x) = Right (One Here x)
get' (There y) (One (There p) x) = mapSnd {elem $= There} $ get' y (One p x)
export %inline
get : (0 err : Type) -> err `Elem` errs =>
OneOf errs -> Either err (OneOf (errs `without` err))
get _ = get' %search
export %inline
noErrorsT : Monad m => ErrorT [] m a -> m a
noErrorsT (MkErrorT act) = act >>= either absurd pure
export %inline
noErrors : Error [] a -> a
noErrors = runIdentity . noErrorsT
public export
data Embed : List a -> List a -> Type where
Nil : Embed [] ys
(::) : x `Elem` ys -> Embed xs ys -> Embed (x::xs) ys
private
embedElem' : Embed xs ys -> x `Elem` xs -> x `Elem` ys
embedElem' (e :: _) Here = e
embedElem' (_ :: es) (There p) = embedElem' es p
export %inline
embedElem : Embed xs ys => x `Elem` xs -> x `Elem` ys
embedElem = embedElem' %search
export %inline
(<|>) : Applicative m => ErrorT errs m a -> ErrorT errs m a -> ErrorT errs m a
MkErrorT act1 <|> MkErrorT act2 = MkErrorT [|act1 `or` act2|] where
or : Either l r -> Either l r -> Either l r
one `or` two = case one of Left err => two; Right x => pure x
public export
interface Monad m => MonadThrow errs m | m where
throw : err `Elem` errs => err -> m a
public export
interface
(MonadThrow errs1 m1,
MonadThrow errs2 m2,
err `Elem` errs1) =>
MonadCatch err errs1 errs2 m1 m2
| err, m1
where
catch : (act : m1 a) -> (catch : err -> m2 a) -> m2 a
public export
interface
(MonadThrow errs1 m1,
MonadThrow errs2 m2,
Embed errs1 errs2) =>
MonadEmbed errs1 errs2 m1 m2
| m1, m2
where
embed : m1 a -> m2 a
export %inline
implementation
Monad m =>
MonadThrow errs (ErrorT errs m)
where
throw = MkErrorT . pure . Left . inj
export %inline
implementation
(Monad m, err `Elem` errs) =>
MonadCatch err errs (errs `without` err)
(ErrorT errs m)
(ErrorT (errs `without` err) m)
where
catch (MkErrorT act) handler = MkErrorT $
act <&> mapFst (get err) >>= \case
Left (Left this) => runErrorT $ handler this
Left (Right other) => pure $ Left other
Right ok => pure $ Right ok
export %inline
implementation
(Monad m, Embed errs1 errs2) =>
MonadEmbed errs1 errs2 (ErrorT errs1 m) (ErrorT errs2 m)
where
embed (MkErrorT act) = MkErrorT $ mapFst {elem $= embedElem} <$> act
export %inline
MonadTrans (ErrorT errs) where lift = MkErrorT . map Right
export %inline
MonadReader r m => MonadReader r (ErrorT errs m) where
local f (MkErrorT act) = MkErrorT $ local f act
ask = lift ask
export %inline
MonadWriter w m => MonadWriter w (ErrorT errs m) where
tell = MkErrorT . map Right . tell
pass (MkErrorT act) = MkErrorT $ pass $ do
Right (res, f) <- act
| Left err => pure (Left err, id)
pure (Right res, f)
listen (MkErrorT act) = MkErrorT $ do
(res, x) <- listen act
pure $ mapSnd (,x) res
export %inline
MonadState s m => MonadState s (ErrorT errs m) where
get = lift get
put = lift . put
state = lift . state
export %inline
MonadRWS r w s m => MonadRWS r w s (ErrorT errs m) where
export %inline
HasIO m => HasIO (ErrorT errs m) where
liftIO = MkErrorT . map Right . liftIO
export %inline
MonadThrow errs m => MonadThrow errs (ReaderT r m) where throw = lift . throw
export %inline
MonadThrow errs m => MonadThrow errs (WriterT w m) where throw = lift . throw
export %inline
MonadThrow errs m => MonadThrow errs (StateT s m) where throw = lift . throw
export %inline
MonadThrow errs m => MonadThrow errs (RWST r w s m) where throw = lift . throw
export %inline
implementation
MonadCatch err errs1 errs2 m1 m2 =>
MonadCatch err errs1 errs2 (ReaderT r m1) (ReaderT r m2)
where
catch (MkReaderT act) handler = MkReaderT $ \r =>
act r `catch` runReaderT r . handler
export %inline
implementation
MonadCatch err errs1 errs2 m1 m2 =>
MonadCatch err errs1 errs2 (WriterT w m1) (WriterT w m2)
where
catch (MkWriterT act) handler = MkWriterT $ \w =>
act w `catch` \e => unWriterT (handler e) w
export %inline
implementation
MonadCatch err errs1 errs2 m1 m2 =>
MonadCatch err errs1 errs2 (StateT s m1) (StateT s m2)
where
catch (ST act) handler = ST $ \s =>
act s `catch` \e => runStateT' (handler e) s
export %inline
implementation
MonadCatch err errs1 errs2 m1 m2 =>
MonadCatch err errs1 errs2 (RWST r w s m1) (RWST r w s m2)
where
catch (MkRWST act) handler = MkRWST $ \r, s, w =>
act r s w `catch` \e => unRWST (handler e) r s w
export %inline
implementation
MonadEmbed errs1 errs2 m1 m2 =>
MonadEmbed errs1 errs2 (ReaderT r m1) (ReaderT r m2)
where
embed (MkReaderT act) = MkReaderT $ embed . act
export %inline
implementation
MonadEmbed errs1 errs2 m1 m2 =>
MonadEmbed errs1 errs2 (WriterT w m1) (WriterT w m2)
where
embed (MkWriterT act) = MkWriterT $ embed . act
export %inline
implementation
MonadEmbed errs1 errs2 m1 m2 =>
MonadEmbed errs1 errs2 (StateT s m1) (StateT s m2)
where
embed (ST act) = ST $ embed . act
export %inline
implementation
MonadEmbed errs1 errs2 m1 m2 =>
MonadEmbed errs1 errs2 (RWST r w s m1) (RWST r w s m2)
where
embed (MkRWST act) = MkRWST $ \r, s, w => embed $ act r s w