sparsec

commit 0007a356a0d8b384665d64ddfa6ce9f6a1e29dc6
parent d5a677742259e1e6f5193f7821c59761f1d1e79b
Author: Robert Russell <robert@rr3.xyz>
Date:   Wed, 24 Dec 2025 18:03:50 -0800

Unbox Result#

Diffstat:
M
src/Sparsec.hs
 | 
73
+++++++++++++++++++++++++++++++++++++++++--------------------------------

1 file changed, 41 insertions(+), 32 deletions(-)
diff --git a/src/Sparsec.hs b/src/Sparsec.hs
@@ -68,7 +68,6 @@ import Data.Foldable
 import Data.Functor
 import GHC.Exts (Int (..), (-#))
 import Numeric.Natural
-import Text.Printf
 import Prelude hiding (fail, not, read)
 
 import Sparsec.Char
@@ -111,37 +110,47 @@ instance Eq State where
 --------------------------------------------------------------------------------
 -- Result#
 
-data Result# e a
-    = Utf8Error# Loc#
-    | Failure#
-    | Error# e
-    | Success# a State#
-
-instance (Eq e, Eq a) => Eq (Result# e a) where
-    Utf8Error# l0 == Utf8Error# l1 = l0 `locEq#` l1
-    Failure# == Failure# = True
-    Error# e0 == Error# e1 = e0 == e1
-    Success# a0 s0 == Success# a1 s1 = a0 == a1 && s0 `stateEq#` s1
-    _ == _ = False
-    {-# INLINE (==) #-}
-
-instance (Show e, Show a) => Show (Result# e a) where
-    show = \case
-        Utf8Error# l -> "utf8 error at " ++ locShow# l
-        Failure# -> "failure"
-        Error# e -> "error: " ++ show e
-        Success# a (State# i _) ->
-            if BS.null i
-                then printf "success: %s" (show a)
-                else printf "success (%d bytes remaining): %s" (BS.length i) (show a)
-
-instance Functor (Result# e) where
-    fmap f = \case
-        Utf8Error# l -> Utf8Error# l
-        Failure# -> Failure#
-        Error# e -> Error# e
-        Success# a s -> Success# (f a) s
-    {-# INLINE fmap #-}
+newtype Result# e a = Result# (# Loc# | (# #) | e | (# a, State# #) #)
+
+pattern Utf8Error# :: Loc# -> Result# e a
+pattern Utf8Error# l = Result# (# l | | | #)
+
+pattern Failure# :: Result# e a
+pattern Failure# = Result# (# | (# #) | | #)
+
+pattern Error# :: e -> Result# e a
+pattern Error# e = Result# (# | | e | #)
+
+pattern Success# :: a -> State# -> Result# e a
+pattern Success# a s = Result# (# | | | (# a, s #) #)
+
+{-# COMPLETE Utf8Error#, Failure#, Error#, Success# #-}
+
+-- instance (Eq e, Eq a) => Eq (Result# e a) where
+--     Utf8Error# l0 == Utf8Error# l1 = l0 `locEq#` l1
+--     Failure# == Failure# = True
+--     Error# e0 == Error# e1 = e0 == e1
+--     Success# a0 s0 == Success# a1 s1 = a0 == a1 && s0 `stateEq#` s1
+--     _ == _ = False
+--     {-# INLINE (==) #-}
+
+-- instance (Show e, Show a) => Show (Result# e a) where
+--     show = \case
+--         Utf8Error# l -> "utf8 error at " ++ locShow# l
+--         Failure# -> "failure"
+--         Error# e -> "error: " ++ show e
+--         Success# a (State# i _) ->
+--             if BS.null i
+--                 then printf "success: %s" (show a)
+--                 else printf "success (%d bytes remaining): %s" (BS.length i) (show a)
+
+-- instance Functor (Result# e) where
+--     fmap f = \case
+--         Utf8Error# l -> Utf8Error# l
+--         Failure# -> Failure#
+--         Error# e -> Error# e
+--         Success# a s -> Success# (f a) s
+--     {-# INLINE fmap #-}
 
 --------------------------------------------------------------------------------
 -- Result