Copyright	(c) 2019-2021 Rudy Matela
License	3-Clause BSD (see the file LICENSE)
Maintainer	Rudy Matela <rudy@matela.com.br>
Safe Haskell	Safe-Inferred
Language	Haskell2010

Data.Express.Express

Description

Defines the Express type class.

Synopsis

class (Show a, Typeable a) => Express a where
- expr :: a -> Expr
(-:) :: a -> a -> a
(->:) :: (a -> b) -> b -> a -> b
(->>:) :: (a -> b -> c) -> c -> a -> b -> c
(->>>:) :: (a -> b -> c -> d) -> d -> a -> b -> c -> d
(->>>>:) :: (a -> b -> c -> d -> e) -> e -> a -> b -> c -> d -> e
(->>>>>:) :: (a -> b -> c -> d -> e -> f) -> f -> a -> b -> c -> d -> e -> f
(->>>>>>:) :: (a -> b -> c -> d -> e -> f -> g) -> g -> a -> b -> c -> d -> e -> f -> g
(->>>>>>>:) :: (a -> b -> c -> d -> e -> f -> g -> h) -> h -> a -> b -> c -> d -> e -> f -> g -> h
(->>>>>>>>:) :: (a -> b -> c -> d -> e -> f -> g -> h -> i) -> i -> a -> b -> c -> d -> e -> f -> g -> h -> i
(->>>>>>>>>:) :: (a -> b -> c -> d -> e -> f -> g -> h -> i -> j) -> j -> a -> b -> c -> d -> e -> f -> g -> h -> i -> j
(->>>>>>>>>>:) :: (a -> b -> c -> d -> e -> f -> g -> h -> i -> j -> k) -> k -> a -> b -> c -> d -> e -> f -> g -> h -> i -> j -> k
(->>>>>>>>>>>:) :: (a -> b -> c -> d -> e -> f -> g -> h -> i -> j -> k -> l) -> l -> a -> b -> c -> d -> e -> f -> g -> h -> i -> j -> k -> l
(->>>>>>>>>>>>:) :: (a -> b -> c -> d -> e -> f -> g -> h -> i -> j -> k -> l -> m) -> m -> a -> b -> c -> d -> e -> f -> g -> h -> i -> j -> k -> l -> m

Documentation

class (Show a, Typeable a) => Express a where Source #

Express typeclass instances provide an expr function that allows values to be deeply encoded as applications of Exprs.

expr False  =  val False
expr (Just True)  =  value "Just" (Just :: Bool -> Maybe Bool) :$ val True

The function expr can be contrasted with the function val:

val always encodes values as atomic Value Exprs -- shallow encoding.
expr ideally encodes expressions as applications (:$) between Value Exprs -- deep encoding.

Depending on the situation, one or the other may be desirable.

Instances can be automatically derived using the TH function deriveExpress.

The following example shows a datatype and its instance:

data Stack a = Stack a (Stack a) | Empty

instance Express a => Express (Stack a) where
  expr s@(Stack x y) = value "Stack" (Stack ->>: s) :$ expr x :$ expr y
  expr s@Empty       = value "Empty" (Empty   -: s)

To declare expr it may be useful to use auxiliary type binding operators: -:, ->:, ->>:, ->>>:, ->>>>:, ->>>>>:, ...

For types with atomic values, just declare expr = val

Methods

expr :: a -> Expr Source #

Instances

Instances details

Express Bool Source #
Instance details Defined in Data.Express.Express Methods expr :: Bool -> Expr Source #
Express Char Source #
Instance details Defined in Data.Express.Express Methods expr :: Char -> Expr Source #
Express Double Source #
Instance details Defined in Data.Express.Express Methods expr :: Double -> Expr Source #
Express Float Source #
Instance details Defined in Data.Express.Express Methods expr :: Float -> Expr Source #
Express Int Source #
Instance details Defined in Data.Express.Express Methods expr :: Int -> Expr Source #
Express Int8 Source #
Instance details Defined in Data.Express.Express Methods expr :: Int8 -> Expr Source #
Express Int16 Source #
Instance details Defined in Data.Express.Express Methods expr :: Int16 -> Expr Source #
Express Int32 Source #
Instance details Defined in Data.Express.Express Methods expr :: Int32 -> Expr Source #
Express Int64 Source #
Instance details Defined in Data.Express.Express Methods expr :: Int64 -> Expr Source #
Express Integer Source #
Instance details Defined in Data.Express.Express Methods expr :: Integer -> Expr Source #
Express Ordering Source #
Instance details Defined in Data.Express.Express Methods expr :: Ordering -> Expr Source #
Express Word Source #
Instance details Defined in Data.Express.Express Methods expr :: Word -> Expr Source #
Express Word8 Source #
Instance details Defined in Data.Express.Express Methods expr :: Word8 -> Expr Source #
Express Word16 Source #
Instance details Defined in Data.Express.Express Methods expr :: Word16 -> Expr Source #
Express Word32 Source #
Instance details Defined in Data.Express.Express Methods expr :: Word32 -> Expr Source #
Express Word64 Source #
Instance details Defined in Data.Express.Express Methods expr :: Word64 -> Expr Source #
Express () Source #
Instance details Defined in Data.Express.Express Methods expr :: () -> Expr Source #
Express GeneralCategory Source #
Instance details Defined in Data.Express.Express Methods expr :: GeneralCategory -> Expr Source #
Express a => Express [a] Source #
Instance details Defined in Data.Express.Express Methods expr :: [a] -> Expr Source #
Express a => Express (Maybe a) Source #
Instance details Defined in Data.Express.Express Methods expr :: Maybe a -> Expr Source #
(Integral a, Express a) => Express (Ratio a) Source #
Instance details Defined in Data.Express.Express Methods expr :: Ratio a -> Expr Source #
(RealFloat a, Express a) => Express (Complex a) Source #
Instance details Defined in Data.Express.Express Methods expr :: Complex a -> Expr Source #
(Express a, Express b) => Express (Either a b) Source #
Instance details Defined in Data.Express.Express Methods expr :: Either a b -> Expr Source #
(Express a, Express b) => Express (a, b) Source #
Instance details Defined in Data.Express.Express Methods expr :: (a, b) -> Expr Source #
(Express a, Express b, Express c) => Express (a, b, c) Source #
Instance details Defined in Data.Express.Express Methods expr :: (a, b, c) -> Expr Source #
(Express a, Express b, Express c, Express d) => Express (a, b, c, d) Source #
Instance details Defined in Data.Express.Express Methods expr :: (a, b, c, d) -> Expr Source #
(Express a, Express b, Express c, Express d, Express e) => Express (a, b, c, d, e) Source #
Instance details Defined in Data.Express.Express Methods expr :: (a, b, c, d, e) -> Expr Source #
(Express a, Express b, Express c, Express d, Express e, Express f) => Express (a, b, c, d, e, f) Source #
Instance details Defined in Data.Express.Express Methods expr :: (a, b, c, d, e, f) -> Expr Source #
(Express a, Express b, Express c, Express d, Express e, Express f, Express g) => Express (a, b, c, d, e, f, g) Source #
Instance details Defined in Data.Express.Express Methods expr :: (a, b, c, d, e, f, g) -> Expr Source #
(Express a, Express b, Express c, Express d, Express e, Express f, Express g, Express h) => Express (a, b, c, d, e, f, g, h) Source #
Instance details Defined in Data.Express.Express Methods expr :: (a, b, c, d, e, f, g, h) -> Expr Source #
(Express a, Express b, Express c, Express d, Express e, Express f, Express g, Express h, Express i) => Express (a, b, c, d, e, f, g, h, i) Source #
Instance details Defined in Data.Express.Express Methods expr :: (a, b, c, d, e, f, g, h, i) -> Expr Source #
(Express a, Express b, Express c, Express d, Express e, Express f, Express g, Express h, Express i, Express j) => Express (a, b, c, d, e, f, g, h, i, j) Source #
Instance details Defined in Data.Express.Express Methods expr :: (a, b, c, d, e, f, g, h, i, j) -> Expr Source #
(Express a, Express b, Express c, Express d, Express e, Express f, Express g, Express h, Express i, Express j, Express k) => Express (a, b, c, d, e, f, g, h, i, j, k) Source #
Instance details Defined in Data.Express.Express Methods expr :: (a, b, c, d, e, f, g, h, i, j, k) -> Expr Source #
(Express a, Express b, Express c, Express d, Express e, Express f, Express g, Express h, Express i, Express j, Express k, Express l) => Express (a, b, c, d, e, f, g, h, i, j, k, l) Source #
Instance details Defined in Data.Express.Express Methods expr :: (a, b, c, d, e, f, g, h, i, j, k, l) -> Expr Source #

(-:) :: a -> a -> a infixl 1 Source #

Type restricted version of const that forces its first argument to have the same type as the second.

 value -: (undefined :: Ty)  =  value :: Ty

(->:) :: (a -> b) -> b -> a -> b infixl 1 Source #

Type restricted version of const that forces the result of its first argument to have the same type as the second.

 f ->: (undefined :: Ty)  =  f :: a -> Ty

(->>:) :: (a -> b -> c) -> c -> a -> b -> c infixl 1 Source #

Type restricted version of const that forces the result of the result of its first argument to have the same type as the second.

f ->>: (undefined :: Ty)  =  f :: a -> b -> Ty

(->>>:) :: (a -> b -> c -> d) -> d -> a -> b -> c -> d infixl 1 Source #

Type restricted version of const that forces the result of the result of the result of its first argument to have the same type as the second.

(->>>>:) :: (a -> b -> c -> d -> e) -> e -> a -> b -> c -> d -> e infixl 1 Source #

Forces the result type of a 4-argument function.

(->>>>>:) :: (a -> b -> c -> d -> e -> f) -> f -> a -> b -> c -> d -> e -> f infixl 1 Source #

Forces the result type of a 5-argument function.

(->>>>>>:) :: (a -> b -> c -> d -> e -> f -> g) -> g -> a -> b -> c -> d -> e -> f -> g infixl 1 Source #

Forces the result type of a 6-argument function.

(->>>>>>>:) :: (a -> b -> c -> d -> e -> f -> g -> h) -> h -> a -> b -> c -> d -> e -> f -> g -> h infixl 1 Source #

Forces the result type of a 7-argument function.

(->>>>>>>>:) :: (a -> b -> c -> d -> e -> f -> g -> h -> i) -> i -> a -> b -> c -> d -> e -> f -> g -> h -> i infixl 1 Source #

Forces the result type of a 8-argument function.

(->>>>>>>>>:) :: (a -> b -> c -> d -> e -> f -> g -> h -> i -> j) -> j -> a -> b -> c -> d -> e -> f -> g -> h -> i -> j infixl 1 Source #

Forces the result type of a 9-argument function.

(->>>>>>>>>>:) :: (a -> b -> c -> d -> e -> f -> g -> h -> i -> j -> k) -> k -> a -> b -> c -> d -> e -> f -> g -> h -> i -> j -> k infixl 1 Source #

Forces the result type of a 10-argument function.

(->>>>>>>>>>>:) :: (a -> b -> c -> d -> e -> f -> g -> h -> i -> j -> k -> l) -> l -> a -> b -> c -> d -> e -> f -> g -> h -> i -> j -> k -> l infixl 1 Source #

Forces the result type of a 11-argument function.

(->>>>>>>>>>>>:) :: (a -> b -> c -> d -> e -> f -> g -> h -> i -> j -> k -> l -> m) -> m -> a -> b -> c -> d -> e -> f -> g -> h -> i -> j -> k -> l -> m infixl 1 Source #

Forces the result type of a 12-argument function.