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| author | Oleg Grenrus <oleg.grenrus@iki.fi> | 2021-01-14 01:44:52 +0200 |
|---|---|---|
| committer | Marge Bot <ben+marge-bot@smart-cactus.org> | 2021-01-18 07:19:34 -0500 |
| commit | 5f1d8be07c17d1c6cdf4c2454229e377c6d23015 (patch) | |
| tree | 606bceaa5e7935e9f099957018db2e03a9493ca2 | |
| parent | 5c312e2354d641c33f3f4bb8e824a6094cc9ce5d (diff) | |
| download | haskell-5f1d8be07c17d1c6cdf4c2454229e377c6d23015.tar.gz | |
Add examples for Complex, (,,) and (,,,) Eq2 etc instances
| -rw-r--r-- | libraries/base/Data/Functor/Classes.hs | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/libraries/base/Data/Functor/Classes.hs b/libraries/base/Data/Functor/Classes.hs index 26d34ff3ff..965bcdafd8 100644 --- a/libraries/base/Data/Functor/Classes.hs +++ b/libraries/base/Data/Functor/Classes.hs @@ -79,6 +79,11 @@ import Text.Read (Read(..), parens, prec, step) import Text.Read.Lex (Lexeme(..)) import Text.Show (showListWith) +-- $setup +-- >>> import Prelude +-- >>> import Data.Complex (Complex (..)) +-- >>> import Text.ParserCombinators.ReadPrec + -- | Lifting of the 'Eq' class to unary type constructors. -- -- @since 4.9.0.0 @@ -522,18 +527,29 @@ instance (Show a) => Show1 ((,) a) where -- | @since 4.16.0.0 +-- +-- >>> eq2 ('x', True, "str") ('x', True, "str") +-- True +-- instance Eq a => Eq2 ((,,) a) where liftEq2 e1 e2 (u1, x1, y1) (v1, x2, y2) = u1 == v1 && e1 x1 x2 && e2 y1 y2 -- | @since 4.16.0.0 +-- +-- >>> compare2 ('x', True, "aaa") ('x', True, "zzz") +-- LT instance Ord a => Ord2 ((,,) a) where liftCompare2 comp1 comp2 (u1, x1, y1) (v1, x2, y2) = compare u1 v1 `mappend` comp1 x1 x2 `mappend` comp2 y1 y2 -- | @since 4.16.0.0 +-- +-- >>> readPrec_to_S readPrec2 0 "('x', True, 2)" :: [((Char, Bool, Int), String)] +-- [(('x',True,2),"")] +-- instance Read a => Read2 ((,,) a) where liftReadPrec2 rp1 _ rp2 _ = parens $ paren $ do x1 <- readPrec @@ -547,6 +563,10 @@ instance Read a => Read2 ((,,) a) where liftReadList2 = liftReadList2Default -- | @since 4.16.0.0 +-- +-- >>> showsPrec2 0 ('x', True, 2 :: Int) "" +-- "('x',True,2)" +-- instance Show a => Show2 ((,,) a) where liftShowsPrec2 sp1 _ sp2 _ _ (x1,y1,y2) = showChar '(' . showsPrec 0 x1 @@ -575,6 +595,10 @@ instance (Show a, Show b) => Show1 ((,,) a b) where -- | @since 4.16.0.0 +-- +-- >>> eq2 ('x', True, "str", 2) ('x', True, "str", 2 :: Int) +-- True +-- instance (Eq a, Eq b) => Eq2 ((,,,) a b) where liftEq2 e1 e2 (u1, u2, x1, y1) (v1, v2, x2, y2) = u1 == v1 && @@ -582,6 +606,10 @@ instance (Eq a, Eq b) => Eq2 ((,,,) a b) where e1 x1 x2 && e2 y1 y2 -- | @since 4.16.0.0 +-- +-- >>> compare2 ('x', True, "str", 2) ('x', True, "str", 3 :: Int) +-- LT +-- instance (Ord a, Ord b) => Ord2 ((,,,) a b) where liftCompare2 comp1 comp2 (u1, u2, x1, y1) (v1, v2, x2, y2) = compare u1 v1 `mappend` @@ -589,6 +617,10 @@ instance (Ord a, Ord b) => Ord2 ((,,,) a b) where comp1 x1 x2 `mappend` comp2 y1 y2 -- | @since 4.16.0.0 +-- +-- >>> readPrec_to_S readPrec2 0 "('x', True, 2, 4.5)" :: [((Char, Bool, Int, Double), String)] +-- [(('x',True,2,4.5),"")] +-- instance (Read a, Read b) => Read2 ((,,,) a b) where liftReadPrec2 rp1 _ rp2 _ = parens $ paren $ do x1 <- readPrec @@ -604,6 +636,10 @@ instance (Read a, Read b) => Read2 ((,,,) a b) where liftReadList2 = liftReadList2Default -- | @since 4.16.0.0 +-- +-- >>> showsPrec2 0 ('x', True, 2 :: Int, 4.5 :: Double) "" +-- "('x',True,2,4.5)" +-- instance (Show a, Show b) => Show2 ((,,,) a b) where liftShowsPrec2 sp1 _ sp2 _ _ (x1,x2,y1,y2) = showChar '(' . showsPrec 0 x1 @@ -776,10 +812,21 @@ instance Show1 Down where liftShowsPrec sp _ d (Down x) = showsUnaryWith sp "Down" d x -- | @since 4.16.0.0 +-- +-- >>> eq1 (1 :+ 2) (1 :+ 2) +-- True +-- +-- >>> eq1 (1 :+ 2) (1 :+ 3) +-- False +-- instance Eq1 Complex where liftEq eq (x :+ y) (u :+ v) = eq x u && eq y v -- | @since 4.16.0.0 +-- +-- >>> readPrec_to_S readPrec1 0 "(2 % 3) :+ (3 % 4)" :: [(Complex Rational, String)] +-- [(2 % 3 :+ 3 % 4,"")] +-- instance Read1 Complex where liftReadPrec rp _ = parens $ prec 9 $ do x <- step rp @@ -791,6 +838,10 @@ instance Read1 Complex where liftReadList = liftReadListDefault -- | @since 4.16.0.0 +-- +-- >>> showsPrec1 0 (2 :+ 3) "" +-- "2 :+ 3" +-- instance Show1 Complex where liftShowsPrec sp _ d (x :+ y) = showParen (d >= 10) $ sp 10 x . showString " :+ " . sp 10 y |