-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/
-- | A compiler for Fay, a Haskell subset that compiles to JavaScript.
--
-- Fay is a proper subset of Haskell which is type-checked with GHC, and
-- compiled to JavaScript. It is lazy, pure, has a Fay monad, an FFI,
-- tail-recursion optimization (experimental), and support for cabal
-- packages.
--
-- Documentation
--
-- See https://github.com/faylang/fay/wiki
--
-- Examples
--
-- See the examples directory and
-- https://github.com/faylang/fay/wiki#fay-in-the-wild
@package fay
@version 0.24.2.0
module Fay.Compiler.Parse
-- | Parse some Fay code.
parseFay :: Parseable ast => FilePath -> String -> ParseResult ast
defaultExtensions :: [Extension]
-- | Re-exports of base functionality. Note that this module is just used
-- inside the compiler. It's not compiled to JavaScript. Based on the
-- base-extended package (c) 2013 Simon Meier, licensed as BSD3.
module Fay.Compiler.Prelude
-- | Append two lists, i.e.,
--
--
-- [x1, ..., xm] ++ [y1, ..., yn] == [x1, ..., xm, y1, ..., yn]
-- [x1, ..., xm] ++ [y1, ...] == [x1, ..., xm, y1, ...]
--
--
-- If the first list is not finite, the result is the first list.
(++) :: [a] -> [a] -> [a]
infixr 5 ++
-- | The value of seq a b is bottom if a is bottom, and
-- otherwise equal to b. In other words, it evaluates the first
-- argument a to weak head normal form (WHNF). seq is
-- usually introduced to improve performance by avoiding unneeded
-- laziness.
--
-- A note on evaluation order: the expression seq a b does
-- not guarantee that a will be evaluated before
-- b. The only guarantee given by seq is that the both
-- a and b will be evaluated before seq
-- returns a value. In particular, this means that b may be
-- evaluated before a. If you need to guarantee a specific order
-- of evaluation, you must use the function pseq from the
-- "parallel" package.
seq :: forall (r :: RuntimeRep) a (b :: TYPE r). a -> b -> b
infixr 0 `seq`
-- | <math>. filter, applied to a predicate and a list,
-- returns the list of those elements that satisfy the predicate; i.e.,
--
--
-- filter p xs = [ x | x <- xs, p x]
--
--
--
-- >>> filter odd [1, 2, 3]
-- [1,3]
--
filter :: (a -> Bool) -> [a] -> [a]
-- | <math>. zip takes two lists and returns a list of
-- corresponding pairs.
--
--
-- zip [1, 2] ['a', 'b'] = [(1, 'a'), (2, 'b')]
--
--
-- If one input list is short, excess elements of the longer list are
-- discarded:
--
--
-- zip [1] ['a', 'b'] = [(1, 'a')]
-- zip [1, 2] ['a'] = [(1, 'a')]
--
--
-- zip is right-lazy:
--
--
-- zip [] _|_ = []
-- zip _|_ [] = _|_
--
--
-- zip is capable of list fusion, but it is restricted to its
-- first list argument and its resulting list.
zip :: [a] -> [b] -> [(a, b)]
-- | The print function outputs a value of any printable type to the
-- standard output device. Printable types are those that are instances
-- of class Show; print converts values to strings for
-- output using the show operation and adds a newline.
--
-- For example, a program to print the first 20 integers and their powers
-- of 2 could be written as:
--
--
-- main = print ([(n, 2^n) | n <- [0..19]])
--
print :: Show a => a -> IO ()
-- | Extract the first component of a pair.
fst :: (a, b) -> a
-- | Extract the second component of a pair.
snd :: (a, b) -> b
-- | otherwise is defined as the value True. It helps to make
-- guards more readable. eg.
--
--
-- f x | x < 0 = ...
-- | otherwise = ...
--
otherwise :: Bool
-- | <math>. map f xs is the list obtained by
-- applying f to each element of xs, i.e.,
--
--
-- map f [x1, x2, ..., xn] == [f x1, f x2, ..., f xn]
-- map f [x1, x2, ...] == [f x1, f x2, ...]
--
--
--
-- >>> map (+1) [1, 2, 3]
--
map :: (a -> b) -> [a] -> [b]
-- | Application operator. This operator is redundant, since ordinary
-- application (f x) means the same as (f $ x).
-- However, $ has low, right-associative binding precedence, so it
-- sometimes allows parentheses to be omitted; for example:
--
--
-- f $ g $ h x = f (g (h x))
--
--
-- It is also useful in higher-order situations, such as map
-- ($ 0) xs, or zipWith ($) fs xs.
--
-- Note that ($) is levity-polymorphic in its result
-- type, so that foo $ True where foo :: Bool ->
-- Int# is well-typed.
($) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b
infixr 0 $
-- | general coercion from integral types
fromIntegral :: (Integral a, Num b) => a -> b
-- | general coercion to fractional types
realToFrac :: (Real a, Fractional b) => a -> b
-- | The Bounded class is used to name the upper and lower limits of
-- a type. Ord is not a superclass of Bounded since types
-- that are not totally ordered may also have upper and lower bounds.
--
-- The Bounded class may be derived for any enumeration type;
-- minBound is the first constructor listed in the data
-- declaration and maxBound is the last. Bounded may also
-- be derived for single-constructor datatypes whose constituent types
-- are in Bounded.
class Bounded a
minBound :: Bounded a => a
maxBound :: Bounded a => a
-- | Class Enum defines operations on sequentially ordered types.
--
-- The enumFrom... methods are used in Haskell's translation of
-- arithmetic sequences.
--
-- Instances of Enum may be derived for any enumeration type
-- (types whose constructors have no fields). The nullary constructors
-- are assumed to be numbered left-to-right by fromEnum from
-- 0 through n-1. See Chapter 10 of the Haskell
-- Report for more details.
--
-- For any type that is an instance of class Bounded as well as
-- Enum, the following should hold:
--
--
--
--
-- enumFrom x = enumFromTo x maxBound
-- enumFromThen x y = enumFromThenTo x y bound
-- where
-- bound | fromEnum y >= fromEnum x = maxBound
-- | otherwise = minBound
--
class Enum a
-- | the successor of a value. For numeric types, succ adds 1.
succ :: Enum a => a -> a
-- | the predecessor of a value. For numeric types, pred subtracts
-- 1.
pred :: Enum a => a -> a
-- | Convert from an Int.
toEnum :: Enum a => Int -> a
-- | Convert to an Int. It is implementation-dependent what
-- fromEnum returns when applied to a value that is too large to
-- fit in an Int.
fromEnum :: Enum a => a -> Int
-- | Used in Haskell's translation of [n..] with [n..] =
-- enumFrom n, a possible implementation being enumFrom n = n :
-- enumFrom (succ n). For example:
--
--
-- enumFrom 4 :: [Integer] = [4,5,6,7,...]
enumFrom 6 :: [Int] = [6,7,8,9,...,maxBound ::
-- Int]
enumFrom :: Enum a => a -> [a]
-- | Used in Haskell's translation of [n,n'..] with [n,n'..] =
-- enumFromThen n n', a possible implementation being
-- enumFromThen n n' = n : n' : worker (f x) (f x n'),
-- worker s v = v : worker s (s v), x = fromEnum n' -
-- fromEnum n and f n y | n > 0 = f (n - 1) (succ y) | n <
-- 0 = f (n + 1) (pred y) | otherwise = y For example:
--
--
-- enumFromThen 4 6 :: [Integer] = [4,6,8,10...]
enumFromThen 6 2 :: [Int] = [6,2,-2,-6,...,minBound ::
-- Int]
enumFromThen :: Enum a => a -> a -> [a]
-- | Used in Haskell's translation of [n..m] with [n..m] =
-- enumFromTo n m, a possible implementation being enumFromTo n
-- m | n <= m = n : enumFromTo (succ n) m | otherwise = []. For
-- example:
--
--
-- enumFromTo 6 10 :: [Int] = [6,7,8,9,10]
enumFromTo 42 1 :: [Integer] = []
enumFromTo :: Enum a => a -> a -> [a]
-- | Used in Haskell's translation of [n,n'..m] with [n,n'..m]
-- = enumFromThenTo n n' m, a possible implementation being
-- enumFromThenTo n n' m = worker (f x) (c x) n m, x =
-- fromEnum n' - fromEnum n, c x = bool (>=) ((x
-- 0) f n y | n > 0 = f (n - 1) (succ y) | n < 0 = f (n +
-- 1) (pred y) | otherwise = y and worker s c v m | c v m = v :
-- worker s c (s v) m | otherwise = [] For example:
--
--
-- enumFromThenTo 4 2 -6 :: [Integer] =
-- [4,2,0,-2,-4,-6]
enumFromThenTo 6 8 2 :: [Int] = []
enumFromThenTo :: Enum a => a -> a -> a -> [a]
-- | The Eq class defines equality (==) and inequality
-- (/=). All the basic datatypes exported by the Prelude
-- are instances of Eq, and Eq may be derived for any
-- datatype whose constituents are also instances of Eq.
--
-- The Haskell Report defines no laws for Eq. However, ==
-- is customarily expected to implement an equivalence relationship where
-- two values comparing equal are indistinguishable by "public"
-- functions, with a "public" function being one not allowing to see
-- implementation details. For example, for a type representing
-- non-normalised natural numbers modulo 100, a "public" function doesn't
-- make the difference between 1 and 201. It is expected to have the
-- following properties:
--
--
-- - Reflexivity x == x = True
-- - Symmetry x == y = y == x
-- - Transitivity if x == y && y == z =
-- True, then x == z = True
-- - Substitutivity if x == y = True and
-- f is a "public" function whose return type is an instance of
-- Eq, then f x == f y = True
-- - Negation x /= y = not (x ==
-- y)
--
--
-- Minimal complete definition: either == or /=.
class Eq a
(==) :: Eq a => a -> a -> Bool
(/=) :: Eq a => a -> a -> Bool
infix 4 ==
infix 4 /=
-- | Trigonometric and hyperbolic functions and related functions.
--
-- The Haskell Report defines no laws for Floating. However,
-- (+), (*) and exp are
-- customarily expected to define an exponential field and have the
-- following properties:
--
--
-- - exp (a + b) = exp a * exp b
-- - exp (fromInteger 0) = fromInteger 1
--
class Fractional a => Floating a
pi :: Floating a => a
log :: Floating a => a -> a
sqrt :: Floating a => a -> a
(**) :: Floating a => a -> a -> a
logBase :: Floating a => a -> a -> a
sin :: Floating a => a -> a
cos :: Floating a => a -> a
tan :: Floating a => a -> a
asin :: Floating a => a -> a
acos :: Floating a => a -> a
atan :: Floating a => a -> a
sinh :: Floating a => a -> a
cosh :: Floating a => a -> a
tanh :: Floating a => a -> a
asinh :: Floating a => a -> a
acosh :: Floating a => a -> a
atanh :: Floating a => a -> a
infixr 8 **
-- | Fractional numbers, supporting real division.
--
-- The Haskell Report defines no laws for Fractional. However,
-- (+) and (*) are customarily expected
-- to define a division ring and have the following properties:
--
--
-- - recip gives the multiplicative inverse x
-- * recip x = recip x * x = fromInteger 1
--
--
-- Note that it isn't customarily expected that a type instance of
-- Fractional implement a field. However, all instances in
-- base do.
class Num a => Fractional a
-- | Fractional division.
(/) :: Fractional a => a -> a -> a
-- | Reciprocal fraction.
recip :: Fractional a => a -> a
-- | Conversion from a Rational (that is Ratio
-- Integer). A floating literal stands for an application of
-- fromRational to a value of type Rational, so such
-- literals have type (Fractional a) => a.
fromRational :: Fractional a => Rational -> a
infixl 7 /
-- | Integral numbers, supporting integer division.
--
-- The Haskell Report defines no laws for Integral. However,
-- Integral instances are customarily expected to define a
-- Euclidean domain and have the following properties for the
-- div/mod and quot/rem pairs, given suitable
-- Euclidean functions f and g:
--
--
-- - x = y * quot x y + rem x y with rem x y
-- = fromInteger 0 or g (rem x y) < g
-- y
-- - x = y * div x y + mod x y with mod x y
-- = fromInteger 0 or f (mod x y) < f
-- y
--
--
-- An example of a suitable Euclidean function, for Integer's
-- instance, is abs.
class (Real a, Enum a) => Integral a
-- | integer division truncated toward zero
quot :: Integral a => a -> a -> a
-- | integer remainder, satisfying
--
--
-- (x `quot` y)*y + (x `rem` y) == x
--
rem :: Integral a => a -> a -> a
-- | integer division truncated toward negative infinity
div :: Integral a => a -> a -> a
-- | simultaneous quot and rem
quotRem :: Integral a => a -> a -> (a, a)
-- | simultaneous div and mod
divMod :: Integral a => a -> a -> (a, a)
-- | conversion to Integer
toInteger :: Integral a => a -> Integer
infixl 7 `div`
infixl 7 `rem`
infixl 7 `quot`
-- | The Monad class defines the basic operations over a
-- monad, a concept from a branch of mathematics known as
-- category theory. From the perspective of a Haskell programmer,
-- however, it is best to think of a monad as an abstract datatype
-- of actions. Haskell's do expressions provide a convenient
-- syntax for writing monadic expressions.
--
-- Instances of Monad should satisfy the following:
--
--
--
-- Furthermore, the Monad and Applicative operations should
-- relate as follows:
--
--
--
-- The above laws imply:
--
--
--
-- and that pure and (<*>) satisfy the applicative
-- functor laws.
--
-- The instances of Monad for lists, Maybe and IO
-- defined in the Prelude satisfy these laws.
class Applicative m => Monad (m :: Type -> Type)
-- | Sequentially compose two actions, passing any value produced by the
-- first as an argument to the second.
--
-- 'as >>= bs' can be understood as the do
-- expression
--
--
-- do a <- as
-- bs a
--
(>>=) :: Monad m => m a -> (a -> m b) -> m b
-- | Sequentially compose two actions, discarding any value produced by the
-- first, like sequencing operators (such as the semicolon) in imperative
-- languages.
--
-- 'as >> bs' can be understood as the do
-- expression
--
--
-- do as
-- bs
--
(>>) :: Monad m => m a -> m b -> m b
-- | Inject a value into the monadic type.
return :: Monad m => a -> m a
infixl 1 >>=
infixl 1 >>
-- | A type f is a Functor if it provides a function fmap
-- which, given any types a and b lets you apply any
-- function from (a -> b) to turn an f a into an
-- f b, preserving the structure of f. Furthermore
-- f needs to adhere to the following:
--
--
--
-- Note, that the second law follows from the free theorem of the type
-- fmap and the first law, so you need only check that the former
-- condition holds.
class Functor (f :: Type -> Type)
-- | Using ApplicativeDo: 'fmap f as' can be
-- understood as the do expression
--
--
-- do a <- as
-- pure (f a)
--
--
-- with an inferred Functor constraint.
fmap :: Functor f => (a -> b) -> f a -> f b
-- | Replace all locations in the input with the same value. The default
-- definition is fmap . const, but this may be
-- overridden with a more efficient version.
--
-- Using ApplicativeDo: 'a <$ bs' can be
-- understood as the do expression
--
--
-- do bs
-- pure a
--
--
-- with an inferred Functor constraint.
(<$) :: Functor f => a -> f b -> f a
infixl 4 <$
-- | Basic numeric class.
--
-- The Haskell Report defines no laws for Num. However,
-- (+) and (*) are customarily expected
-- to define a ring and have the following properties:
--
--
-- - Associativity of (+) (x + y) +
-- z = x + (y + z)
-- - Commutativity of (+) x + y
-- = y + x
-- - fromInteger 0 is the additive
-- identity x + fromInteger 0 = x
-- - negate gives the additive inverse x +
-- negate x = fromInteger 0
-- - Associativity of (*) (x * y) *
-- z = x * (y * z)
-- - fromInteger 1 is the multiplicative
-- identity x * fromInteger 1 = x and
-- fromInteger 1 * x = x
-- - Distributivity of (*) with respect to
-- (+) a * (b + c) = (a * b) + (a *
-- c) and (b + c) * a = (b * a) + (c * a)
--
--
-- Note that it isn't customarily expected that a type instance of
-- both Num and Ord implement an ordered ring. Indeed, in
-- base only Integer and Rational do.
class Num a
(+) :: Num a => a -> a -> a
(-) :: Num a => a -> a -> a
(*) :: Num a => a -> a -> a
-- | Unary negation.
negate :: Num a => a -> a
-- | Absolute value.
abs :: Num a => a -> a
-- | Sign of a number. The functions abs and signum should
-- satisfy the law:
--
--
-- abs x * signum x == x
--
--
-- For real numbers, the signum is either -1 (negative),
-- 0 (zero) or 1 (positive).
signum :: Num a => a -> a
-- | Conversion from an Integer. An integer literal represents the
-- application of the function fromInteger to the appropriate
-- value of type Integer, so such literals have type
-- (Num a) => a.
fromInteger :: Num a => Integer -> a
infixl 6 -
infixl 6 +
infixl 7 *
-- | The Ord class is used for totally ordered datatypes.
--
-- Instances of Ord can be derived for any user-defined datatype
-- whose constituent types are in Ord. The declared order of the
-- constructors in the data declaration determines the ordering in
-- derived Ord instances. The Ordering datatype allows a
-- single comparison to determine the precise ordering of two objects.
--
-- The Haskell Report defines no laws for Ord. However,
-- <= is customarily expected to implement a non-strict partial
-- order and have the following properties:
--
--
-- - Transitivity if x <= y && y <=
-- z = True, then x <= z = True
-- - Reflexivity x <= x = True
-- - Antisymmetry if x <= y && y <=
-- x = True, then x == y = True
--
--
-- Note that the following operator interactions are expected to hold:
--
--
-- - x >= y = y <= x
-- - x < y = x <= y && x /= y
-- - x > y = y < x
-- - x < y = compare x y == LT
-- - x > y = compare x y == GT
-- - x == y = compare x y == EQ
-- - min x y == if x <= y then x else y = True
-- - max x y == if x >= y then x else y = True
--
--
-- Note that (7.) and (8.) do not require min and
-- max to return either of their arguments. The result is merely
-- required to equal one of the arguments in terms of (==).
--
-- Minimal complete definition: either compare or <=.
-- Using compare can be more efficient for complex types.
class Eq a => Ord a
compare :: Ord a => a -> a -> Ordering
(<) :: Ord a => a -> a -> Bool
(<=) :: Ord a => a -> a -> Bool
(>) :: Ord a => a -> a -> Bool
(>=) :: Ord a => a -> a -> Bool
max :: Ord a => a -> a -> a
min :: Ord a => a -> a -> a
infix 4 <
infix 4 <=
infix 4 >
infix 4 >=
-- | Parsing of Strings, producing values.
--
-- Derived instances of Read make the following assumptions, which
-- derived instances of Show obey:
--
--
-- - If the constructor is defined to be an infix operator, then the
-- derived Read instance will parse only infix applications of the
-- constructor (not the prefix form).
-- - Associativity is not used to reduce the occurrence of parentheses,
-- although precedence may be.
-- - If the constructor is defined using record syntax, the derived
-- Read will parse only the record-syntax form, and furthermore,
-- the fields must be given in the same order as the original
-- declaration.
-- - The derived Read instance allows arbitrary Haskell
-- whitespace between tokens of the input string. Extra parentheses are
-- also allowed.
--
--
-- For example, given the declarations
--
--
-- infixr 5 :^:
-- data Tree a = Leaf a | Tree a :^: Tree a
--
--
-- the derived instance of Read in Haskell 2010 is equivalent to
--
--
-- instance (Read a) => Read (Tree a) where
--
-- readsPrec d r = readParen (d > app_prec)
-- (\r -> [(Leaf m,t) |
-- ("Leaf",s) <- lex r,
-- (m,t) <- readsPrec (app_prec+1) s]) r
--
-- ++ readParen (d > up_prec)
-- (\r -> [(u:^:v,w) |
-- (u,s) <- readsPrec (up_prec+1) r,
-- (":^:",t) <- lex s,
-- (v,w) <- readsPrec (up_prec+1) t]) r
--
-- where app_prec = 10
-- up_prec = 5
--
--
-- Note that right-associativity of :^: is unused.
--
-- The derived instance in GHC is equivalent to
--
--
-- instance (Read a) => Read (Tree a) where
--
-- readPrec = parens $ (prec app_prec $ do
-- Ident "Leaf" <- lexP
-- m <- step readPrec
-- return (Leaf m))
--
-- +++ (prec up_prec $ do
-- u <- step readPrec
-- Symbol ":^:" <- lexP
-- v <- step readPrec
-- return (u :^: v))
--
-- where app_prec = 10
-- up_prec = 5
--
-- readListPrec = readListPrecDefault
--
--
-- Why do both readsPrec and readPrec exist, and why does
-- GHC opt to implement readPrec in derived Read instances
-- instead of readsPrec? The reason is that readsPrec is
-- based on the ReadS type, and although ReadS is mentioned
-- in the Haskell 2010 Report, it is not a very efficient parser data
-- structure.
--
-- readPrec, on the other hand, is based on a much more efficient
-- ReadPrec datatype (a.k.a "new-style parsers"), but its
-- definition relies on the use of the RankNTypes language
-- extension. Therefore, readPrec (and its cousin,
-- readListPrec) are marked as GHC-only. Nevertheless, it is
-- recommended to use readPrec instead of readsPrec
-- whenever possible for the efficiency improvements it brings.
--
-- As mentioned above, derived Read instances in GHC will
-- implement readPrec instead of readsPrec. The default
-- implementations of readsPrec (and its cousin, readList)
-- will simply use readPrec under the hood. If you are writing a
-- Read instance by hand, it is recommended to write it like so:
--
--
-- instance Read T where
-- readPrec = ...
-- readListPrec = readListPrecDefault
--
class Read a
-- | attempts to parse a value from the front of the string, returning a
-- list of (parsed value, remaining string) pairs. If there is no
-- successful parse, the returned list is empty.
--
-- Derived instances of Read and Show satisfy the
-- following:
--
--
--
-- That is, readsPrec parses the string produced by
-- showsPrec, and delivers the value that showsPrec started
-- with.
readsPrec :: Read a => Int -> ReadS a
-- | The method readList is provided to allow the programmer to give
-- a specialised way of parsing lists of values. For example, this is
-- used by the predefined Read instance of the Char type,
-- where values of type String should be are expected to use
-- double quotes, rather than square brackets.
readList :: Read a => ReadS [a]
class (Num a, Ord a) => Real a
-- | the rational equivalent of its real argument with full precision
toRational :: Real a => a -> Rational
-- | Efficient, machine-independent access to the components of a
-- floating-point number.
class (RealFrac a, Floating a) => RealFloat a
-- | a constant function, returning the radix of the representation (often
-- 2)
floatRadix :: RealFloat a => a -> Integer
-- | a constant function, returning the number of digits of
-- floatRadix in the significand
floatDigits :: RealFloat a => a -> Int
-- | a constant function, returning the lowest and highest values the
-- exponent may assume
floatRange :: RealFloat a => a -> (Int, Int)
-- | The function decodeFloat applied to a real floating-point
-- number returns the significand expressed as an Integer and an
-- appropriately scaled exponent (an Int). If
-- decodeFloat x yields (m,n), then x
-- is equal in value to m*b^^n, where b is the
-- floating-point radix, and furthermore, either m and
-- n are both zero or else b^(d-1) <= abs m <
-- b^d, where d is the value of floatDigits
-- x. In particular, decodeFloat 0 = (0,0). If the
-- type contains a negative zero, also decodeFloat (-0.0) =
-- (0,0). The result of decodeFloat x is
-- unspecified if either of isNaN x or
-- isInfinite x is True.
decodeFloat :: RealFloat a => a -> (Integer, Int)
-- | encodeFloat performs the inverse of decodeFloat in the
-- sense that for finite x with the exception of -0.0,
-- uncurry encodeFloat (decodeFloat x) = x.
-- encodeFloat m n is one of the two closest
-- representable floating-point numbers to m*b^^n (or
-- ±Infinity if overflow occurs); usually the closer, but if
-- m contains too many bits, the result may be rounded in the
-- wrong direction.
encodeFloat :: RealFloat a => Integer -> Int -> a
-- | exponent corresponds to the second component of
-- decodeFloat. exponent 0 = 0 and for finite
-- nonzero x, exponent x = snd (decodeFloat x)
-- + floatDigits x. If x is a finite floating-point
-- number, it is equal in value to significand x * b ^^
-- exponent x, where b is the floating-point radix.
-- The behaviour is unspecified on infinite or NaN values.
exponent :: RealFloat a => a -> Int
-- | The first component of decodeFloat, scaled to lie in the open
-- interval (-1,1), either 0.0 or of absolute
-- value >= 1/b, where b is the floating-point
-- radix. The behaviour is unspecified on infinite or NaN
-- values.
significand :: RealFloat a => a -> a
-- | multiplies a floating-point number by an integer power of the radix
scaleFloat :: RealFloat a => Int -> a -> a
-- | True if the argument is an IEEE "not-a-number" (NaN) value
isNaN :: RealFloat a => a -> Bool
-- | True if the argument is an IEEE infinity or negative infinity
isInfinite :: RealFloat a => a -> Bool
-- | True if the argument is too small to be represented in
-- normalized format
isDenormalized :: RealFloat a => a -> Bool
-- | True if the argument is an IEEE negative zero
isNegativeZero :: RealFloat a => a -> Bool
-- | True if the argument is an IEEE floating point number
isIEEE :: RealFloat a => a -> Bool
-- | a version of arctangent taking two real floating-point arguments. For
-- real floating x and y, atan2 y x
-- computes the angle (from the positive x-axis) of the vector from the
-- origin to the point (x,y). atan2 y x returns
-- a value in the range [-pi, pi]. It follows the
-- Common Lisp semantics for the origin when signed zeroes are supported.
-- atan2 y 1, with y in a type that is
-- RealFloat, should return the same value as atan
-- y. A default definition of atan2 is provided, but
-- implementors can provide a more accurate implementation.
atan2 :: RealFloat a => a -> a -> a
-- | Extracting components of fractions.
class (Real a, Fractional a) => RealFrac a
-- | The function properFraction takes a real fractional number
-- x and returns a pair (n,f) such that x =
-- n+f, and:
--
--
-- - n is an integral number with the same sign as x;
-- and
-- - f is a fraction with the same type and sign as
-- x, and with absolute value less than 1.
--
--
-- The default definitions of the ceiling, floor,
-- truncate and round functions are in terms of
-- properFraction.
properFraction :: (RealFrac a, Integral b) => a -> (b, a)
-- | truncate x returns the integer nearest x
-- between zero and x
truncate :: (RealFrac a, Integral b) => a -> b
-- | round x returns the nearest integer to x; the
-- even integer if x is equidistant between two integers
round :: (RealFrac a, Integral b) => a -> b
-- | ceiling x returns the least integer not less than
-- x
ceiling :: (RealFrac a, Integral b) => a -> b
-- | floor x returns the greatest integer not greater than
-- x
floor :: (RealFrac a, Integral b) => a -> b
-- | Conversion of values to readable Strings.
--
-- Derived instances of Show have the following properties, which
-- are compatible with derived instances of Read:
--
--
-- - The result of show is a syntactically correct Haskell
-- expression containing only constants, given the fixity declarations in
-- force at the point where the type is declared. It contains only the
-- constructor names defined in the data type, parentheses, and spaces.
-- When labelled constructor fields are used, braces, commas, field
-- names, and equal signs are also used.
-- - If the constructor is defined to be an infix operator, then
-- showsPrec will produce infix applications of the
-- constructor.
-- - the representation will be enclosed in parentheses if the
-- precedence of the top-level constructor in x is less than
-- d (associativity is ignored). Thus, if d is
-- 0 then the result is never surrounded in parentheses; if
-- d is 11 it is always surrounded in parentheses,
-- unless it is an atomic expression.
-- - If the constructor is defined using record syntax, then
-- show will produce the record-syntax form, with the fields given
-- in the same order as the original declaration.
--
--
-- For example, given the declarations
--
--
-- infixr 5 :^:
-- data Tree a = Leaf a | Tree a :^: Tree a
--
--
-- the derived instance of Show is equivalent to
--
--
-- instance (Show a) => Show (Tree a) where
--
-- showsPrec d (Leaf m) = showParen (d > app_prec) $
-- showString "Leaf " . showsPrec (app_prec+1) m
-- where app_prec = 10
--
-- showsPrec d (u :^: v) = showParen (d > up_prec) $
-- showsPrec (up_prec+1) u .
-- showString " :^: " .
-- showsPrec (up_prec+1) v
-- where up_prec = 5
--
--
-- Note that right-associativity of :^: is ignored. For example,
--
--
-- - show (Leaf 1 :^: Leaf 2 :^: Leaf 3) produces the
-- string "Leaf 1 :^: (Leaf 2 :^: Leaf 3)".
--
class Show a
-- | Convert a value to a readable String.
--
-- showsPrec should satisfy the law
--
--
-- showsPrec d x r ++ s == showsPrec d x (r ++ s)
--
--
-- Derived instances of Read and Show satisfy the
-- following:
--
--
--
-- That is, readsPrec parses the string produced by
-- showsPrec, and delivers the value that showsPrec started
-- with.
showsPrec :: Show a => Int -> a -> ShowS
-- | A specialised variant of showsPrec, using precedence context
-- zero, and returning an ordinary String.
show :: Show a => a -> String
-- | The method showList is provided to allow the programmer to give
-- a specialised way of showing lists of values. For example, this is
-- used by the predefined Show instance of the Char type,
-- where values of type String should be shown in double quotes,
-- rather than between square brackets.
showList :: Show a => [a] -> ShowS
-- | When a value is bound in do-notation, the pattern on the left
-- hand side of <- might not match. In this case, this class
-- provides a function to recover.
--
-- A Monad without a MonadFail instance may only be used in
-- conjunction with pattern that always match, such as newtypes, tuples,
-- data types with only a single data constructor, and irrefutable
-- patterns (~pat).
--
-- Instances of MonadFail should satisfy the following law:
-- fail s should be a left zero for >>=,
--
--
-- fail s >>= f = fail s
--
--
-- If your Monad is also MonadPlus, a popular definition is
--
--
-- fail _ = mzero
--
class Monad m => MonadFail (m :: Type -> Type)
fail :: MonadFail m => String -> m a
-- | A functor with application, providing operations to
--
--
-- - embed pure expressions (pure), and
-- - sequence computations and combine their results (<*>
-- and liftA2).
--
--
-- A minimal complete definition must include implementations of
-- pure and of either <*> or liftA2. If it
-- defines both, then they must behave the same as their default
-- definitions:
--
--
-- (<*>) = liftA2 id
--
--
--
-- liftA2 f x y = f <$> x <*> y
--
--
-- Further, any definition must satisfy the following:
--
--
--
-- The other methods have the following default definitions, which may be
-- overridden with equivalent specialized implementations:
--
--
--
-- As a consequence of these laws, the Functor instance for
-- f will satisfy
--
--
--
-- It may be useful to note that supposing
--
--
-- forall x y. p (q x y) = f x . g y
--
--
-- it follows from the above that
--
--
-- liftA2 p (liftA2 q u v) = liftA2 f u . liftA2 g v
--
--
-- If f is also a Monad, it should satisfy
--
--
--
-- (which implies that pure and <*> satisfy the
-- applicative functor laws).
class Functor f => Applicative (f :: Type -> Type)
-- | Lift a value.
pure :: Applicative f => a -> f a
-- | Sequential application.
--
-- A few functors support an implementation of <*> that is
-- more efficient than the default one.
--
-- Using ApplicativeDo: 'fs <*> as' can be
-- understood as the do expression
--
--
-- do f <- fs
-- a <- as
-- pure (f a)
--
(<*>) :: Applicative f => f (a -> b) -> f a -> f b
-- | Sequence actions, discarding the value of the first argument.
--
-- 'as *> bs' can be understood as the do
-- expression
--
--
-- do as
-- bs
--
--
-- This is a tad complicated for our ApplicativeDo extension
-- which will give it a Monad constraint. For an
-- Applicative constraint we write it of the form
--
--
-- do _ <- as
-- b <- bs
-- pure b
--
(*>) :: Applicative f => f a -> f b -> f b
-- | Sequence actions, discarding the value of the second argument.
--
-- Using ApplicativeDo: 'as <* bs' can be
-- understood as the do expression
--
--
-- do a <- as
-- bs
-- pure a
--
(<*) :: Applicative f => f a -> f b -> f a
infixl 4 <*
infixl 4 *>
infixl 4 <*>
-- | Data structures that can be folded.
--
-- For example, given a data type
--
--
-- data Tree a = Empty | Leaf a | Node (Tree a) a (Tree a)
--
--
-- a suitable instance would be
--
--
-- instance Foldable Tree where
-- foldMap f Empty = mempty
-- foldMap f (Leaf x) = f x
-- foldMap f (Node l k r) = foldMap f l `mappend` f k `mappend` foldMap f r
--
--
-- This is suitable even for abstract types, as the monoid is assumed to
-- satisfy the monoid laws. Alternatively, one could define
-- foldr:
--
--
-- instance Foldable Tree where
-- foldr f z Empty = z
-- foldr f z (Leaf x) = f x z
-- foldr f z (Node l k r) = foldr f (f k (foldr f z r)) l
--
--
-- Foldable instances are expected to satisfy the following
-- laws:
--
--
-- foldr f z t = appEndo (foldMap (Endo . f) t ) z
--
--
--
-- foldl f z t = appEndo (getDual (foldMap (Dual . Endo . flip f) t)) z
--
--
--
-- fold = foldMap id
--
--
--
-- length = getSum . foldMap (Sum . const 1)
--
--
-- sum, product, maximum, and minimum
-- should all be essentially equivalent to foldMap forms, such
-- as
--
--
-- sum = getSum . foldMap Sum
--
--
-- but may be less defined.
--
-- If the type is also a Functor instance, it should satisfy
--
--
-- foldMap f = fold . fmap f
--
--
-- which implies that
--
--
-- foldMap f . fmap g = foldMap (f . g)
--
class Foldable (t :: Type -> Type)
-- | Map each element of the structure to a monoid, and combine the
-- results.
foldMap :: (Foldable t, Monoid m) => (a -> m) -> t a -> m
-- | Right-associative fold of a structure.
--
-- In the case of lists, foldr, when applied to a binary operator,
-- a starting value (typically the right-identity of the operator), and a
-- list, reduces the list using the binary operator, from right to left:
--
--
-- foldr f z [x1, x2, ..., xn] == x1 `f` (x2 `f` ... (xn `f` z)...)
--
--
-- Note that, since the head of the resulting expression is produced by
-- an application of the operator to the first element of the list,
-- foldr can produce a terminating expression from an infinite
-- list.
--
-- For a general Foldable structure this should be semantically
-- identical to,
--
--
-- foldr f z = foldr f z . toList
--
foldr :: Foldable t => (a -> b -> b) -> b -> t a -> b
-- | Left-associative fold of a structure.
--
-- In the case of lists, foldl, when applied to a binary operator,
-- a starting value (typically the left-identity of the operator), and a
-- list, reduces the list using the binary operator, from left to right:
--
--
-- foldl f z [x1, x2, ..., xn] == (...((z `f` x1) `f` x2) `f`...) `f` xn
--
--
-- Note that to produce the outermost application of the operator the
-- entire input list must be traversed. This means that foldl'
-- will diverge if given an infinite list.
--
-- Also note that if you want an efficient left-fold, you probably want
-- to use foldl' instead of foldl. The reason for this is
-- that latter does not force the "inner" results (e.g. z `f` x1
-- in the above example) before applying them to the operator (e.g. to
-- (`f` x2)). This results in a thunk chain <math>
-- elements long, which then must be evaluated from the outside-in.
--
-- For a general Foldable structure this should be semantically
-- identical to,
--
--
-- foldl f z = foldl f z . toList
--
foldl :: Foldable t => (b -> a -> b) -> b -> t a -> b
-- | A variant of foldr that has no base case, and thus may only be
-- applied to non-empty structures.
--
--
-- foldr1 f = foldr1 f . toList
--
foldr1 :: Foldable t => (a -> a -> a) -> t a -> a
-- | A variant of foldl that has no base case, and thus may only be
-- applied to non-empty structures.
--
--
-- foldl1 f = foldl1 f . toList
--
foldl1 :: Foldable t => (a -> a -> a) -> t a -> a
-- | Test whether the structure is empty. The default implementation is
-- optimized for structures that are similar to cons-lists, because there
-- is no general way to do better.
null :: Foldable t => t a -> Bool
-- | Returns the size/length of a finite structure as an Int. The
-- default implementation is optimized for structures that are similar to
-- cons-lists, because there is no general way to do better.
length :: Foldable t => t a -> Int
-- | Does the element occur in the structure?
elem :: (Foldable t, Eq a) => a -> t a -> Bool
-- | The largest element of a non-empty structure.
maximum :: (Foldable t, Ord a) => t a -> a
-- | The least element of a non-empty structure.
minimum :: (Foldable t, Ord a) => t a -> a
-- | The sum function computes the sum of the numbers of a
-- structure.
sum :: (Foldable t, Num a) => t a -> a
-- | The product function computes the product of the numbers of a
-- structure.
product :: (Foldable t, Num a) => t a -> a
infix 4 `elem`
-- | Functors representing data structures that can be traversed from left
-- to right.
--
-- A definition of traverse must satisfy the following laws:
--
--
--
-- A definition of sequenceA must satisfy the following laws:
--
--
--
-- where an applicative transformation is a function
--
--
-- t :: (Applicative f, Applicative g) => f a -> g a
--
--
-- preserving the Applicative operations, i.e.
--
--
-- t (pure x) = pure x
-- t (f <*> x) = t f <*> t x
--
--
-- and the identity functor Identity and composition functors
-- Compose are from Data.Functor.Identity and
-- Data.Functor.Compose.
--
-- A result of the naturality law is a purity law for traverse
--
--
-- traverse pure = pure
--
--
-- (The naturality law is implied by parametricity and thus so is the
-- purity law [1, p15].)
--
-- Instances are similar to Functor, e.g. given a data type
--
--
-- data Tree a = Empty | Leaf a | Node (Tree a) a (Tree a)
--
--
-- a suitable instance would be
--
--
-- instance Traversable Tree where
-- traverse f Empty = pure Empty
-- traverse f (Leaf x) = Leaf <$> f x
-- traverse f (Node l k r) = Node <$> traverse f l <*> f k <*> traverse f r
--
--
-- This is suitable even for abstract types, as the laws for
-- <*> imply a form of associativity.
--
-- The superclass instances should satisfy the following:
--
--
-- - In the Functor instance, fmap should be equivalent
-- to traversal with the identity applicative functor
-- (fmapDefault).
-- - In the Foldable instance, foldMap should be
-- equivalent to traversal with a constant applicative functor
-- (foldMapDefault).
--
--
-- References: [1] The Essence of the Iterator Pattern, Jeremy Gibbons
-- and Bruno C. d. S. Oliveira
class (Functor t, Foldable t) => Traversable (t :: Type -> Type)
-- | Map each element of a structure to an action, evaluate these actions
-- from left to right, and collect the results. For a version that
-- ignores the results see traverse_.
traverse :: (Traversable t, Applicative f) => (a -> f b) -> t a -> f (t b)
-- | Evaluate each action in the structure from left to right, and collect
-- the results. For a version that ignores the results see
-- sequenceA_.
sequenceA :: (Traversable t, Applicative f) => t (f a) -> f (t a)
-- | Map each element of a structure to a monadic action, evaluate these
-- actions from left to right, and collect the results. For a version
-- that ignores the results see mapM_.
mapM :: (Traversable t, Monad m) => (a -> m b) -> t a -> m (t b)
-- | Evaluate each monadic action in the structure from left to right, and
-- collect the results. For a version that ignores the results see
-- sequence_.
sequence :: (Traversable t, Monad m) => t (m a) -> m (t a)
-- | The class of semigroups (types with an associative binary operation).
--
-- Instances should satisfy the following:
--
--
-- - Associativity x <> (y <> z) =
-- (x <> y) <> z
--
class Semigroup a
-- | An associative operation.
--
--
-- >>> [1,2,3] <> [4,5,6]
-- [1,2,3,4,5,6]
--
(<>) :: Semigroup a => a -> a -> a
infixr 6 <>
-- | The class of monoids (types with an associative binary operation that
-- has an identity). Instances should satisfy the following:
--
--
--
-- The method names refer to the monoid of lists under concatenation, but
-- there are many other instances.
--
-- Some types can be viewed as a monoid in more than one way, e.g. both
-- addition and multiplication on numbers. In such cases we often define
-- newtypes and make those instances of Monoid, e.g.
-- Sum and Product.
--
-- NOTE: Semigroup is a superclass of Monoid since
-- base-4.11.0.0.
class Semigroup a => Monoid a
-- | Identity of mappend
--
--
-- >>> "Hello world" <> mempty
-- "Hello world"
--
mempty :: Monoid a => a
-- | An associative operation
--
-- NOTE: This method is redundant and has the default
-- implementation mappend = (<>) since
-- base-4.11.0.0. Should it be implemented manually, since
-- mappend is a synonym for (<>), it is expected that
-- the two functions are defined the same way. In a future GHC release
-- mappend will be removed from Monoid.
mappend :: Monoid a => a -> a -> a
-- | Fold a list using the monoid.
--
-- For most types, the default definition for mconcat will be
-- used, but the function is included in the class definition so that an
-- optimized version can be provided for specific types.
--
--
-- >>> mconcat ["Hello", " ", "Haskell", "!"]
-- "Hello Haskell!"
--
mconcat :: Monoid a => [a] -> a
data Bool
False :: Bool
True :: Bool
-- | The character type Char is an enumeration whose values
-- represent Unicode (or equivalently ISO/IEC 10646) code points (i.e.
-- characters, see http://www.unicode.org/ for details). This set
-- extends the ISO 8859-1 (Latin-1) character set (the first 256
-- characters), which is itself an extension of the ASCII character set
-- (the first 128 characters). A character literal in Haskell has type
-- Char.
--
-- To convert a Char to or from the corresponding Int value
-- defined by Unicode, use toEnum and fromEnum from the
-- Enum class respectively (or equivalently ord and
-- chr).
data Char
-- | Double-precision floating point numbers. It is desirable that this
-- type be at least equal in range and precision to the IEEE
-- double-precision type.
data Double
-- | Single-precision floating point numbers. It is desirable that this
-- type be at least equal in range and precision to the IEEE
-- single-precision type.
data Float
-- | A fixed-precision integer type with at least the range [-2^29 ..
-- 2^29-1]. The exact range for a given implementation can be
-- determined by using minBound and maxBound from the
-- Bounded class.
data Int
-- | Arbitrary precision integers. In contrast with fixed-size integral
-- types such as Int, the Integer type represents the
-- entire infinite range of integers.
--
-- For more information about this type's representation, see the
-- comments in its implementation.
data Integer
-- | The Maybe type encapsulates an optional value. A value of type
-- Maybe a either contains a value of type a
-- (represented as Just a), or it is empty (represented
-- as Nothing). Using Maybe is a good way to deal with
-- errors or exceptional cases without resorting to drastic measures such
-- as error.
--
-- The Maybe type is also a monad. It is a simple kind of error
-- monad, where all errors are represented by Nothing. A richer
-- error monad can be built using the Either type.
data Maybe a
Nothing :: Maybe a
Just :: a -> Maybe a
data Ordering
LT :: Ordering
EQ :: Ordering
GT :: Ordering
-- | Arbitrary-precision rational numbers, represented as a ratio of two
-- Integer values. A rational number may be constructed using the
-- % operator.
type Rational = Ratio Integer
-- | A value of type IO a is a computation which, when
-- performed, does some I/O before returning a value of type a.
--
-- There is really only one way to "perform" an I/O action: bind it to
-- Main.main in your program. When your program is run, the I/O
-- will be performed. It isn't possible to perform I/O from an arbitrary
-- function, unless that function is itself in the IO monad and
-- called at some point, directly or indirectly, from Main.main.
--
-- IO is a monad, so IO actions can be combined using
-- either the do-notation or the >> and >>=
-- operations from the Monad class.
data IO a
-- | A Word is an unsigned integral type, with the same size as
-- Int.
data Word
-- | The Either type represents values with two possibilities: a
-- value of type Either a b is either Left
-- a or Right b.
--
-- The Either type is sometimes used to represent a value which is
-- either correct or an error; by convention, the Left constructor
-- is used to hold an error value and the Right constructor is
-- used to hold a correct value (mnemonic: "right" also means "correct").
--
-- Examples
--
-- The type Either String Int is the type
-- of values which can be either a String or an Int. The
-- Left constructor can be used only on Strings, and the
-- Right constructor can be used only on Ints:
--
--
-- >>> let s = Left "foo" :: Either String Int
--
-- >>> s
-- Left "foo"
--
-- >>> let n = Right 3 :: Either String Int
--
-- >>> n
-- Right 3
--
-- >>> :type s
-- s :: Either String Int
--
-- >>> :type n
-- n :: Either String Int
--
--
-- The fmap from our Functor instance will ignore
-- Left values, but will apply the supplied function to values
-- contained in a Right:
--
--
-- >>> let s = Left "foo" :: Either String Int
--
-- >>> let n = Right 3 :: Either String Int
--
-- >>> fmap (*2) s
-- Left "foo"
--
-- >>> fmap (*2) n
-- Right 6
--
--
-- The Monad instance for Either allows us to chain
-- together multiple actions which may fail, and fail overall if any of
-- the individual steps failed. First we'll write a function that can
-- either parse an Int from a Char, or fail.
--
--
-- >>> import Data.Char ( digitToInt, isDigit )
--
-- >>> :{
-- let parseEither :: Char -> Either String Int
-- parseEither c
-- | isDigit c = Right (digitToInt c)
-- | otherwise = Left "parse error"
--
-- >>> :}
--
--
-- The following should work, since both '1' and '2'
-- can be parsed as Ints.
--
--
-- >>> :{
-- let parseMultiple :: Either String Int
-- parseMultiple = do
-- x <- parseEither '1'
-- y <- parseEither '2'
-- return (x + y)
--
-- >>> :}
--
--
--
-- >>> parseMultiple
-- Right 3
--
--
-- But the following should fail overall, since the first operation where
-- we attempt to parse 'm' as an Int will fail:
--
--
-- >>> :{
-- let parseMultiple :: Either String Int
-- parseMultiple = do
-- x <- parseEither 'm'
-- y <- parseEither '2'
-- return (x + y)
--
-- >>> :}
--
--
--
-- >>> parseMultiple
-- Left "parse error"
--
data Either a b
Left :: a -> Either a b
Right :: b -> Either a b
-- | A String is a list of characters. String constants in Haskell
-- are values of type String.
--
-- See Data.List for operations on lists.
type String = [Char]
-- | An infix synonym for fmap.
--
-- The name of this operator is an allusion to $. Note the
-- similarities between their types:
--
--
-- ($) :: (a -> b) -> a -> b
-- (<$>) :: Functor f => (a -> b) -> f a -> f b
--
--
-- Whereas $ is function application, <$> is function
-- application lifted over a Functor.
--
-- Examples
--
-- Convert from a Maybe Int to a Maybe
-- String using show:
--
--
-- >>> show <$> Nothing
-- Nothing
--
-- >>> show <$> Just 3
-- Just "3"
--
--
-- Convert from an Either Int Int to an
-- Either Int String using show:
--
--
-- >>> show <$> Left 17
-- Left 17
--
-- >>> show <$> Right 17
-- Right "17"
--
--
-- Double each element of a list:
--
--
-- >>> (*2) <$> [1,2,3]
-- [2,4,6]
--
--
-- Apply even to the second element of a pair:
--
--
-- >>> even <$> (2,2)
-- (2,True)
--
(<$>) :: Functor f => (a -> b) -> f a -> f b
infixl 4 <$>
-- | const x is a unary function which evaluates to x for
-- all inputs.
--
--
-- >>> const 42 "hello"
-- 42
--
--
--
-- >>> map (const 42) [0..3]
-- [42,42,42,42]
--
const :: a -> b -> a
-- | Function composition.
(.) :: (b -> c) -> (a -> b) -> a -> c
infixr 9 .
-- | Identity function.
--
--
-- id x = x
--
id :: a -> a
-- | The shows functions return a function that prepends the
-- output String to an existing String. This allows
-- constant-time concatenation of results using function composition.
type ShowS = String -> String
-- | The read function reads input from a string, which must be
-- completely consumed by the input process. read fails with an
-- error if the parse is unsuccessful, and it is therefore
-- discouraged from being used in real applications. Use readMaybe
-- or readEither for safe alternatives.
--
--
-- >>> read "123" :: Int
-- 123
--
--
--
-- >>> read "hello" :: Int
-- *** Exception: Prelude.read: no parse
--
read :: Read a => String -> a
-- | The readIO function is similar to read except that it
-- signals parse failure to the IO monad instead of terminating
-- the program.
readIO :: Read a => String -> IO a
-- | The readLn function combines getLine and readIO.
readLn :: Read a => IO a
-- | The computation appendFile file str function appends
-- the string str, to the file file.
--
-- Note that writeFile and appendFile write a literal
-- string to a file. To write a value of any printable type, as with
-- print, use the show function to convert the value to a
-- string first.
--
--
-- main = appendFile "squares" (show [(x,x*x) | x <- [0,0.1..2]])
--
appendFile :: FilePath -> String -> IO ()
-- | The computation writeFile file str function writes the
-- string str, to the file file.
writeFile :: FilePath -> String -> IO ()
-- | The readFile function reads a file and returns the contents of
-- the file as a string. The file is read lazily, on demand, as with
-- getContents.
readFile :: FilePath -> IO String
-- | The interact function takes a function of type
-- String->String as its argument. The entire input from the
-- standard input device is passed to this function as its argument, and
-- the resulting string is output on the standard output device.
interact :: (String -> String) -> IO ()
-- | The getContents operation returns all user input as a single
-- string, which is read lazily as it is needed (same as
-- hGetContents stdin).
getContents :: IO String
-- | Read a line from the standard input device (same as hGetLine
-- stdin).
getLine :: IO String
-- | Read a character from the standard input device (same as
-- hGetChar stdin).
getChar :: IO Char
-- | The same as putStr, but adds a newline character.
putStrLn :: String -> IO ()
-- | Write a string to the standard output device (same as hPutStr
-- stdout).
putStr :: String -> IO ()
-- | Write a character to the standard output device (same as
-- hPutChar stdout).
putChar :: Char -> IO ()
-- | Raise an IOError in the IO monad.
ioError :: IOError -> IO a
-- | File and directory names are values of type String, whose
-- precise meaning is operating system dependent. Files can be opened,
-- yielding a handle which can then be used to operate on the contents of
-- that file.
type FilePath = String
-- | Construct an IOError value with a string describing the error.
-- The fail method of the IO instance of the Monad
-- class raises a userError, thus:
--
--
-- instance Monad IO where
-- ...
-- fail s = ioError (userError s)
--
userError :: String -> IOError
-- | The Haskell 2010 type for exceptions in the IO monad. Any I/O
-- operation may raise an IOError instead of returning a result.
-- For a more general type of exception, including also those that arise
-- in pure code, see Exception.
--
-- In Haskell 2010, this is an opaque type.
type IOError = IOException
-- | notElem is the negation of elem.
notElem :: (Foldable t, Eq a) => a -> t a -> Bool
infix 4 `notElem`
-- | Determines whether all elements of the structure satisfy the
-- predicate.
all :: Foldable t => (a -> Bool) -> t a -> Bool
-- | Determines whether any element of the structure satisfies the
-- predicate.
any :: Foldable t => (a -> Bool) -> t a -> Bool
-- | or returns the disjunction of a container of Bools. For the
-- result to be False, the container must be finite; True,
-- however, results from a True value finitely far from the left
-- end.
or :: Foldable t => t Bool -> Bool
-- | and returns the conjunction of a container of Bools. For the
-- result to be True, the container must be finite; False,
-- however, results from a False value finitely far from the left
-- end.
and :: Foldable t => t Bool -> Bool
-- | Map a function over all the elements of a container and concatenate
-- the resulting lists.
concatMap :: Foldable t => (a -> [b]) -> t a -> [b]
-- | The concatenation of all the elements of a container of lists.
concat :: Foldable t => t [a] -> [a]
-- | Evaluate each monadic action in the structure from left to right, and
-- ignore the results. For a version that doesn't ignore the results see
-- sequence.
--
-- As of base 4.8.0.0, sequence_ is just sequenceA_,
-- specialized to Monad.
sequence_ :: (Foldable t, Monad m) => t (m a) -> m ()
-- | Map each element of a structure to a monadic action, evaluate these
-- actions from left to right, and ignore the results. For a version that
-- doesn't ignore the results see mapM.
--
-- As of base 4.8.0.0, mapM_ is just traverse_, specialized
-- to Monad.
mapM_ :: (Foldable t, Monad m) => (a -> m b) -> t a -> m ()
-- | unwords is an inverse operation to words. It joins words
-- with separating spaces.
--
--
-- >>> unwords ["Lorem", "ipsum", "dolor"]
-- "Lorem ipsum dolor"
--
unwords :: [String] -> String
-- | words breaks a string up into a list of words, which were
-- delimited by white space.
--
--
-- >>> words "Lorem ipsum\ndolor"
-- ["Lorem","ipsum","dolor"]
--
words :: String -> [String]
-- | unlines is an inverse operation to lines. It joins
-- lines, after appending a terminating newline to each.
--
--
-- >>> unlines ["Hello", "World", "!"]
-- "Hello\nWorld\n!\n"
--
unlines :: [String] -> String
-- | lines breaks a string up into a list of strings at newline
-- characters. The resulting strings do not contain newlines.
--
-- Note that after splitting the string at newline characters, the last
-- part of the string is considered a line even if it doesn't end with a
-- newline. For example,
--
--
-- >>> lines ""
-- []
--
--
--
-- >>> lines "\n"
-- [""]
--
--
--
-- >>> lines "one"
-- ["one"]
--
--
--
-- >>> lines "one\n"
-- ["one"]
--
--
--
-- >>> lines "one\n\n"
-- ["one",""]
--
--
--
-- >>> lines "one\ntwo"
-- ["one","two"]
--
--
--
-- >>> lines "one\ntwo\n"
-- ["one","two"]
--
--
-- Thus lines s contains at least as many elements as
-- newlines in s.
lines :: String -> [String]
-- | equivalent to readsPrec with a precedence of 0.
reads :: Read a => ReadS a
-- | Case analysis for the Either type. If the value is
-- Left a, apply the first function to a; if it
-- is Right b, apply the second function to b.
--
-- Examples
--
-- We create two values of type Either String
-- Int, one using the Left constructor and another
-- using the Right constructor. Then we apply "either" the
-- length function (if we have a String) or the "times-two"
-- function (if we have an Int):
--
--
-- >>> let s = Left "foo" :: Either String Int
--
-- >>> let n = Right 3 :: Either String Int
--
-- >>> either length (*2) s
-- 3
--
-- >>> either length (*2) n
-- 6
--
either :: (a -> c) -> (b -> c) -> Either a b -> c
-- | The lex function reads a single lexeme from the input,
-- discarding initial white space, and returning the characters that
-- constitute the lexeme. If the input string contains only white space,
-- lex returns a single successful `lexeme' consisting of the
-- empty string. (Thus lex "" = [("","")].) If there is
-- no legal lexeme at the beginning of the input string, lex fails
-- (i.e. returns []).
--
-- This lexer is not completely faithful to the Haskell lexical syntax in
-- the following respects:
--
--
-- - Qualified names are not handled properly
-- - Octal and hexadecimal numerics are not recognized as a single
-- token
-- - Comments are not treated properly
--
lex :: ReadS String
-- | readParen True p parses what p parses,
-- but surrounded with parentheses.
--
-- readParen False p parses what p
-- parses, but optionally surrounded with parentheses.
readParen :: Bool -> ReadS a -> ReadS a
-- | A parser for a type a, represented as a function that takes a
-- String and returns a list of possible parses as
-- (a,String) pairs.
--
-- Note that this kind of backtracking parser is very inefficient;
-- reading a large structure may be quite slow (cf ReadP).
type ReadS a = String -> [(a, String)]
-- | lcm x y is the smallest positive integer that both
-- x and y divide.
lcm :: Integral a => a -> a -> a
-- | gcd x y is the non-negative factor of both x
-- and y of which every common factor of x and
-- y is also a factor; for example gcd 4 2 = 2,
-- gcd (-4) 6 = 2, gcd 0 4 = 4.
-- gcd 0 0 = 0. (That is, the common divisor
-- that is "greatest" in the divisibility preordering.)
--
-- Note: Since for signed fixed-width integer types, abs
-- minBound < 0, the result may be negative if one of the
-- arguments is minBound (and necessarily is if the other
-- is 0 or minBound) for such types.
gcd :: Integral a => a -> a -> a
-- | raise a number to an integral power
(^^) :: (Fractional a, Integral b) => a -> b -> a
infixr 8 ^^
-- | raise a number to a non-negative integral power
(^) :: (Num a, Integral b) => a -> b -> a
infixr 8 ^
odd :: Integral a => a -> Bool
even :: Integral a => a -> Bool
-- | utility function that surrounds the inner show function with
-- parentheses when the Bool parameter is True.
showParen :: Bool -> ShowS -> ShowS
-- | utility function converting a String to a show function that
-- simply prepends the string unchanged.
showString :: String -> ShowS
-- | utility function converting a Char to a show function that
-- simply prepends the character unchanged.
showChar :: Char -> ShowS
-- | equivalent to showsPrec with a precedence of 0.
shows :: Show a => a -> ShowS
-- | The unzip3 function takes a list of triples and returns three
-- lists, analogous to unzip.
unzip3 :: [(a, b, c)] -> ([a], [b], [c])
-- | unzip transforms a list of pairs into a list of first
-- components and a list of second components.
unzip :: [(a, b)] -> ([a], [b])
-- | The zipWith3 function takes a function which combines three
-- elements, as well as three lists and returns a list of their
-- point-wise combination, analogous to zipWith. It is capable of
-- list fusion, but it is restricted to its first list argument and its
-- resulting list.
zipWith3 :: (a -> b -> c -> d) -> [a] -> [b] -> [c] -> [d]
-- | <math>. zipWith generalises zip by zipping with
-- the function given as the first argument, instead of a tupling
-- function. For example, zipWith (+) is applied to two
-- lists to produce the list of corresponding sums:
--
--
-- >>> zipWith (+) [1, 2, 3] [4, 5, 6]
-- [5,7,9]
--
--
-- zipWith is right-lazy:
--
--
-- zipWith f [] _|_ = []
--
--
-- zipWith is capable of list fusion, but it is restricted to its
-- first list argument and its resulting list.
zipWith :: (a -> b -> c) -> [a] -> [b] -> [c]
-- | zip3 takes three lists and returns a list of triples, analogous
-- to zip. It is capable of list fusion, but it is restricted to
-- its first list argument and its resulting list.
zip3 :: [a] -> [b] -> [c] -> [(a, b, c)]
-- | List index (subscript) operator, starting from 0. It is an instance of
-- the more general genericIndex, which takes an index of any
-- integral type.
(!!) :: [a] -> Int -> a
infixl 9 !!
-- | <math>. lookup key assocs looks up a key in an
-- association list.
--
--
-- >>> lookup 2 [(1, "first"), (2, "second"), (3, "third")]
-- Just "second"
--
lookup :: Eq a => a -> [(a, b)] -> Maybe b
-- | reverse xs returns the elements of xs in
-- reverse order. xs must be finite.
reverse :: [a] -> [a]
-- | break, applied to a predicate p and a list
-- xs, returns a tuple where first element is longest prefix
-- (possibly empty) of xs of elements that do not satisfy
-- p and second element is the remainder of the list:
--
--
-- break (> 3) [1,2,3,4,1,2,3,4] == ([1,2,3],[4,1,2,3,4])
-- break (< 9) [1,2,3] == ([],[1,2,3])
-- break (> 9) [1,2,3] == ([1,2,3],[])
--
--
-- break p is equivalent to span (not .
-- p).
break :: (a -> Bool) -> [a] -> ([a], [a])
-- | span, applied to a predicate p and a list xs,
-- returns a tuple where first element is longest prefix (possibly empty)
-- of xs of elements that satisfy p and second element
-- is the remainder of the list:
--
--
-- span (< 3) [1,2,3,4,1,2,3,4] == ([1,2],[3,4,1,2,3,4])
-- span (< 9) [1,2,3] == ([1,2,3],[])
-- span (< 0) [1,2,3] == ([],[1,2,3])
--
--
-- span p xs is equivalent to (takeWhile p xs,
-- dropWhile p xs)
span :: (a -> Bool) -> [a] -> ([a], [a])
-- | splitAt n xs returns a tuple where first element is
-- xs prefix of length n and second element is the
-- remainder of the list:
--
--
-- splitAt 6 "Hello World!" == ("Hello ","World!")
-- splitAt 3 [1,2,3,4,5] == ([1,2,3],[4,5])
-- splitAt 1 [1,2,3] == ([1],[2,3])
-- splitAt 3 [1,2,3] == ([1,2,3],[])
-- splitAt 4 [1,2,3] == ([1,2,3],[])
-- splitAt 0 [1,2,3] == ([],[1,2,3])
-- splitAt (-1) [1,2,3] == ([],[1,2,3])
--
--
-- It is equivalent to (take n xs, drop n xs) when
-- n is not _|_ (splitAt _|_ xs = _|_).
-- splitAt is an instance of the more general
-- genericSplitAt, in which n may be of any integral
-- type.
splitAt :: Int -> [a] -> ([a], [a])
-- | drop n xs returns the suffix of xs after the
-- first n elements, or [] if n > length
-- xs:
--
--
-- drop 6 "Hello World!" == "World!"
-- drop 3 [1,2,3,4,5] == [4,5]
-- drop 3 [1,2] == []
-- drop 3 [] == []
-- drop (-1) [1,2] == [1,2]
-- drop 0 [1,2] == [1,2]
--
--
-- It is an instance of the more general genericDrop, in which
-- n may be of any integral type.
drop :: Int -> [a] -> [a]
-- | take n, applied to a list xs, returns the
-- prefix of xs of length n, or xs itself if
-- n > length xs:
--
--
-- take 5 "Hello World!" == "Hello"
-- take 3 [1,2,3,4,5] == [1,2,3]
-- take 3 [1,2] == [1,2]
-- take 3 [] == []
-- take (-1) [1,2] == []
-- take 0 [1,2] == []
--
--
-- It is an instance of the more general genericTake, in which
-- n may be of any integral type.
take :: Int -> [a] -> [a]
-- | dropWhile p xs returns the suffix remaining after
-- takeWhile p xs:
--
--
-- dropWhile (< 3) [1,2,3,4,5,1,2,3] == [3,4,5,1,2,3]
-- dropWhile (< 9) [1,2,3] == []
-- dropWhile (< 0) [1,2,3] == [1,2,3]
--
dropWhile :: (a -> Bool) -> [a] -> [a]
-- | takeWhile, applied to a predicate p and a list
-- xs, returns the longest prefix (possibly empty) of
-- xs of elements that satisfy p:
--
--
-- takeWhile (< 3) [1,2,3,4,1,2,3,4] == [1,2]
-- takeWhile (< 9) [1,2,3] == [1,2,3]
-- takeWhile (< 0) [1,2,3] == []
--
takeWhile :: (a -> Bool) -> [a] -> [a]
-- | cycle ties a finite list into a circular one, or equivalently,
-- the infinite repetition of the original list. It is the identity on
-- infinite lists.
cycle :: [a] -> [a]
-- | replicate n x is a list of length n with
-- x the value of every element. It is an instance of the more
-- general genericReplicate, in which n may be of any
-- integral type.
replicate :: Int -> a -> [a]
-- | repeat x is an infinite list, with x the
-- value of every element.
repeat :: a -> [a]
-- | iterate f x returns an infinite list of repeated
-- applications of f to x:
--
--
-- iterate f x == [x, f x, f (f x), ...]
--
--
-- Note that iterate is lazy, potentially leading to thunk
-- build-up if the consumer doesn't force each iterate. See
-- iterate' for a strict variant of this function.
iterate :: (a -> a) -> a -> [a]
-- | <math>. scanr1 is a variant of scanr that has no
-- starting value argument.
scanr1 :: (a -> a -> a) -> [a] -> [a]
-- | <math>. scanr is the right-to-left dual of scanl.
-- Note that
--
--
-- head (scanr f z xs) == foldr f z xs.
--
scanr :: (a -> b -> b) -> b -> [a] -> [b]
-- | <math>. scanl1 is a variant of scanl that has no
-- starting value argument:
--
--
-- scanl1 f [x1, x2, ...] == [x1, x1 `f` x2, ...]
--
scanl1 :: (a -> a -> a) -> [a] -> [a]
-- | <math>. scanl is similar to foldl, but returns a
-- list of successive reduced values from the left:
--
--
-- scanl f z [x1, x2, ...] == [z, z `f` x1, (z `f` x1) `f` x2, ...]
--
--
-- Note that
--
--
-- last (scanl f z xs) == foldl f z xs.
--
scanl :: (b -> a -> b) -> b -> [a] -> [b]
-- | <math>. Return all the elements of a list except the last one.
-- The list must be non-empty.
init :: [a] -> [a]
-- | <math>. Extract the last element of a list, which must be finite
-- and non-empty.
last :: [a] -> a
-- | <math>. Extract the elements after the head of a list, which
-- must be non-empty.
tail :: [a] -> [a]
-- | <math>. Extract the first element of a list, which must be
-- non-empty.
head :: [a] -> a
-- | The maybe function takes a default value, a function, and a
-- Maybe value. If the Maybe value is Nothing, the
-- function returns the default value. Otherwise, it applies the function
-- to the value inside the Just and returns the result.
--
-- Examples
--
-- Basic usage:
--
--
-- >>> maybe False odd (Just 3)
-- True
--
--
--
-- >>> maybe False odd Nothing
-- False
--
--
-- Read an integer from a string using readMaybe. If we succeed,
-- return twice the integer; that is, apply (*2) to it. If
-- instead we fail to parse an integer, return 0 by default:
--
--
-- >>> import Text.Read ( readMaybe )
--
-- >>> maybe 0 (*2) (readMaybe "5")
-- 10
--
-- >>> maybe 0 (*2) (readMaybe "")
-- 0
--
--
-- Apply show to a Maybe Int. If we have Just n,
-- we want to show the underlying Int n. But if we have
-- Nothing, we return the empty string instead of (for example)
-- "Nothing":
--
--
-- >>> maybe "" show (Just 5)
-- "5"
--
-- >>> maybe "" show Nothing
-- ""
--
maybe :: b -> (a -> b) -> Maybe a -> b
-- | uncurry converts a curried function to a function on pairs.
--
-- Examples
--
--
-- >>> uncurry (+) (1,2)
-- 3
--
--
--
-- >>> uncurry ($) (show, 1)
-- "1"
--
--
--
-- >>> map (uncurry max) [(1,2), (3,4), (6,8)]
-- [2,4,8]
--
uncurry :: (a -> b -> c) -> (a, b) -> c
-- | curry converts an uncurried function to a curried function.
--
-- Examples
--
--
-- >>> curry fst 1 2
-- 1
--
curry :: ((a, b) -> c) -> a -> b -> c
-- | the same as flip (-).
--
-- Because - is treated specially in the Haskell grammar,
-- (- e) is not a section, but an application of
-- prefix negation. However, (subtract
-- exp) is equivalent to the disallowed section.
subtract :: Num a => a -> a -> a
-- | asTypeOf is a type-restricted version of const. It is
-- usually used as an infix operator, and its typing forces its first
-- argument (which is usually overloaded) to have the same type as the
-- second.
asTypeOf :: a -> a -> a
-- | until p f yields the result of applying f
-- until p holds.
until :: (a -> Bool) -> (a -> a) -> a -> a
-- | Strict (call-by-value) application operator. It takes a function and
-- an argument, evaluates the argument to weak head normal form (WHNF),
-- then calls the function with that value.
($!) :: forall (r :: RuntimeRep) a (b :: TYPE r). (a -> b) -> a -> b
infixr 0 $!
-- | flip f takes its (first) two arguments in the reverse
-- order of f.
--
--
-- >>> flip (++) "hello" "world"
-- "worldhello"
--
flip :: (a -> b -> c) -> b -> a -> c
-- | Same as >>=, but with the arguments interchanged.
(=<<) :: Monad m => (a -> m b) -> m a -> m b
infixr 1 =<<
-- | A special case of error. It is expected that compilers will
-- recognize this and insert error messages which are more appropriate to
-- the context in which undefined appears.
undefined :: forall (r :: RuntimeRep) (a :: TYPE r). HasCallStack => a
-- | A variant of error that does not produce a stack trace.
errorWithoutStackTrace :: forall (r :: RuntimeRep) (a :: TYPE r). [Char] -> a
-- | error stops execution and displays an error message.
error :: forall (r :: RuntimeRep) (a :: TYPE r). HasCallStack => [Char] -> a
-- | Boolean "and", lazy in the second argument
(&&) :: Bool -> Bool -> Bool
infixr 3 &&
-- | Boolean "or", lazy in the second argument
(||) :: Bool -> Bool -> Bool
infixr 2 ||
-- | Boolean "not"
not :: Bool -> Bool
-- | Fanout: send the input to both argument arrows and combine their
-- output.
--
-- The default definition may be overridden with a more efficient version
-- if desired.
(&&&) :: Arrow a => a b c -> a b c' -> a b (c, c')
infixr 3 &&&
-- | A mirror image of first.
--
-- The default definition may be overridden with a more efficient version
-- if desired.
second :: Arrow a => a b c -> a (d, b) (d, c)
-- | Send the first component of the input through the argument arrow, and
-- copy the rest unchanged to the output.
first :: Arrow a => a b c -> a (b, d) (c, d)
-- | Split the input between the two argument arrows and combine their
-- output. Note that this is in general not a functor.
--
-- The default definition may be overridden with a more efficient version
-- if desired.
(***) :: Arrow a => a b c -> a b' c' -> a (b, b') (c, c')
infixr 3 ***
-- | Fanin: Split the input between the two argument arrows and merge their
-- outputs.
--
-- The default definition may be overridden with a more efficient version
-- if desired.
(|||) :: ArrowChoice a => a b d -> a c d -> a (Either b c) d
infixr 2 |||
-- | Split the input between the two argument arrows, retagging and merging
-- their outputs. Note that this is in general not a functor.
--
-- The default definition may be overridden with a more efficient version
-- if desired.
(+++) :: ArrowChoice a => a b c -> a b' c' -> a (Either b b') (Either c c')
infixr 2 +++
-- | The join function is the conventional monad join operator. It
-- is used to remove one level of monadic structure, projecting its bound
-- argument into the outer level.
--
-- 'join bss' can be understood as the do
-- expression
--
--
-- do bs <- bss
-- bs
--
--
-- Examples
--
-- A common use of join is to run an IO computation
-- returned from an STM transaction, since STM transactions
-- can't perform IO directly. Recall that
--
--
-- atomically :: STM a -> IO a
--
--
-- is used to run STM transactions atomically. So, by specializing
-- the types of atomically and join to
--
--
-- atomically :: STM (IO b) -> IO (IO b)
-- join :: IO (IO b) -> IO b
--
--
-- we can compose them as
--
--
-- join . atomically :: STM (IO b) -> IO b
--
--
-- to run an STM transaction and the IO action it returns.
join :: Monad m => m (m a) -> m a
-- | The Monad class defines the basic operations over a
-- monad, a concept from a branch of mathematics known as
-- category theory. From the perspective of a Haskell programmer,
-- however, it is best to think of a monad as an abstract datatype
-- of actions. Haskell's do expressions provide a convenient
-- syntax for writing monadic expressions.
--
-- Instances of Monad should satisfy the following:
--
--
--
-- Furthermore, the Monad and Applicative operations should
-- relate as follows:
--
--
--
-- The above laws imply:
--
--
--
-- and that pure and (<*>) satisfy the applicative
-- functor laws.
--
-- The instances of Monad for lists, Maybe and IO
-- defined in the Prelude satisfy these laws.
class Applicative m => Monad (m :: Type -> Type)
-- | Sequentially compose two actions, passing any value produced by the
-- first as an argument to the second.
--
-- 'as >>= bs' can be understood as the do
-- expression
--
--
-- do a <- as
-- bs a
--
(>>=) :: Monad m => m a -> (a -> m b) -> m b
-- | Sequentially compose two actions, discarding any value produced by the
-- first, like sequencing operators (such as the semicolon) in imperative
-- languages.
--
-- 'as >> bs' can be understood as the do
-- expression
--
--
-- do as
-- bs
--
(>>) :: Monad m => m a -> m b -> m b
-- | Inject a value into the monadic type.
return :: Monad m => a -> m a
infixl 1 >>=
infixl 1 >>
-- | A type f is a Functor if it provides a function fmap
-- which, given any types a and b lets you apply any
-- function from (a -> b) to turn an f a into an
-- f b, preserving the structure of f. Furthermore
-- f needs to adhere to the following:
--
--
--
-- Note, that the second law follows from the free theorem of the type
-- fmap and the first law, so you need only check that the former
-- condition holds.
class Functor (f :: Type -> Type)
-- | Using ApplicativeDo: 'fmap f as' can be
-- understood as the do expression
--
--
-- do a <- as
-- pure (f a)
--
--
-- with an inferred Functor constraint.
fmap :: Functor f => (a -> b) -> f a -> f b
-- | Replace all locations in the input with the same value. The default
-- definition is fmap . const, but this may be
-- overridden with a more efficient version.
--
-- Using ApplicativeDo: 'a <$ bs' can be
-- understood as the do expression
--
--
-- do bs
-- pure a
--
--
-- with an inferred Functor constraint.
(<$) :: Functor f => a -> f b -> f a
infixl 4 <$
-- | When a value is bound in do-notation, the pattern on the left
-- hand side of <- might not match. In this case, this class
-- provides a function to recover.
--
-- A Monad without a MonadFail instance may only be used in
-- conjunction with pattern that always match, such as newtypes, tuples,
-- data types with only a single data constructor, and irrefutable
-- patterns (~pat).
--
-- Instances of MonadFail should satisfy the following law:
-- fail s should be a left zero for >>=,
--
--
-- fail s >>= f = fail s
--
--
-- If your Monad is also MonadPlus, a popular definition is
--
--
-- fail _ = mzero
--
class Monad m => MonadFail (m :: Type -> Type)
fail :: MonadFail m => String -> m a
-- | Map each element of a structure to a monadic action, evaluate these
-- actions from left to right, and collect the results. For a version
-- that ignores the results see mapM_.
mapM :: (Traversable t, Monad m) => (a -> m b) -> t a -> m (t b)
-- | Evaluate each monadic action in the structure from left to right, and
-- collect the results. For a version that ignores the results see
-- sequence_.
sequence :: (Traversable t, Monad m) => t (m a) -> m (t a)
-- | Monads that also support choice and failure.
class (Alternative m, Monad m) => MonadPlus (m :: Type -> Type)
-- | The identity of mplus. It should also satisfy the equations
--
--
-- mzero >>= f = mzero
-- v >> mzero = mzero
--
--
-- The default definition is
--
--
-- mzero = empty
--
mzero :: MonadPlus m => m a
-- | An associative operation. The default definition is
--
--
-- mplus = (<|>)
--
mplus :: MonadPlus m => m a -> m a -> m a
-- | Direct MonadPlus equivalent of filter.
--
-- Examples
--
-- The filter function is just mfilter specialized to the
-- list monad:
--
--
-- filter = ( mfilter :: (a -> Bool) -> [a] -> [a] )
--
--
-- An example using mfilter with the Maybe monad:
--
--
-- >>> mfilter odd (Just 1)
-- Just 1
-- >>> mfilter odd (Just 2)
-- Nothing
--
mfilter :: MonadPlus m => (a -> Bool) -> m a -> m a
-- | Strict version of <$>.
(<$!>) :: Monad m => (a -> b) -> m a -> m b
infixl 4 <$!>
-- | The reverse of when.
unless :: Applicative f => Bool -> f () -> f ()
-- | Like replicateM, but discards the result.
replicateM_ :: Applicative m => Int -> m a -> m ()
-- | replicateM n act performs the action n times,
-- gathering the results.
--
-- Using ApplicativeDo: 'replicateM 5 as' can be
-- understood as the do expression
--
--
-- do a1 <- as
-- a2 <- as
-- a3 <- as
-- a4 <- as
-- a5 <- as
-- pure [a1,a2,a3,a4,a5]
--
--
-- Note the Applicative constraint.
replicateM :: Applicative m => Int -> m a -> m [a]
-- | Like foldM, but discards the result.
foldM_ :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m ()
-- | The foldM function is analogous to foldl, except that
-- its result is encapsulated in a monad. Note that foldM works
-- from left-to-right over the list arguments. This could be an issue
-- where (>>) and the `folded function' are not
-- commutative.
--
--
-- foldM f a1 [x1, x2, ..., xm]
--
-- ==
--
-- do
-- a2 <- f a1 x1
-- a3 <- f a2 x2
-- ...
-- f am xm
--
--
-- If right-to-left evaluation is required, the input list should be
-- reversed.
--
-- Note: foldM is the same as foldlM
foldM :: (Foldable t, Monad m) => (b -> a -> m b) -> b -> t a -> m b
-- | zipWithM_ is the extension of zipWithM which ignores the
-- final result.
zipWithM_ :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m ()
-- | The zipWithM function generalizes zipWith to arbitrary
-- applicative functors.
zipWithM :: Applicative m => (a -> b -> m c) -> [a] -> [b] -> m [c]
-- | The mapAndUnzipM function maps its first argument over a list,
-- returning the result as a pair of lists. This function is mainly used
-- with complicated data structures or a state monad.
mapAndUnzipM :: Applicative m => (a -> m (b, c)) -> [a] -> m ([b], [c])
-- | Repeat an action indefinitely.
--
-- Using ApplicativeDo: 'forever as' can be
-- understood as the pseudo-do expression
--
--
-- do as
-- as
-- ..
--
--
-- with as repeating.
--
-- Examples
--
-- A common use of forever is to process input from network
-- sockets, Handles, and channels (e.g. MVar and
-- Chan).
--
-- For example, here is how we might implement an echo server,
-- using forever both to listen for client connections on a
-- network socket and to echo client input on client connection handles:
--
--
-- echoServer :: Socket -> IO ()
-- echoServer socket = forever $ do
-- client <- accept socket
-- forkFinally (echo client) (\_ -> hClose client)
-- where
-- echo :: Handle -> IO ()
-- echo client = forever $
-- hGetLine client >>= hPutStrLn client
--
forever :: Applicative f => f a -> f b
-- | Right-to-left composition of Kleisli arrows.
-- (>=>), with the arguments flipped.
--
-- Note how this operator resembles function composition
-- (.):
--
--
-- (.) :: (b -> c) -> (a -> b) -> a -> c
-- (<=<) :: Monad m => (b -> m c) -> (a -> m b) -> a -> m c
--
(<=<) :: Monad m => (b -> m c) -> (a -> m b) -> a -> m c
infixr 1 <=<
-- | Left-to-right composition of Kleisli arrows.
--
-- '(bs >=> cs) a' can be understood as the
-- do expression
--
--
-- do b <- bs a
-- cs b
--
(>=>) :: Monad m => (a -> m b) -> (b -> m c) -> a -> m c
infixr 1 >=>
-- | This generalizes the list-based filter function.
filterM :: Applicative m => (a -> m Bool) -> [a] -> m [a]
-- | forM is mapM with its arguments flipped. For a version
-- that ignores the results see forM_.
forM :: (Traversable t, Monad m) => t a -> (a -> m b) -> m (t b)
-- | The sum of a collection of actions, generalizing concat. As of
-- base 4.8.0.0, msum is just asum, specialized to
-- MonadPlus.
msum :: (Foldable t, MonadPlus m) => t (m a) -> m a
-- | Evaluate each monadic action in the structure from left to right, and
-- ignore the results. For a version that doesn't ignore the results see
-- sequence.
--
-- As of base 4.8.0.0, sequence_ is just sequenceA_,
-- specialized to Monad.
sequence_ :: (Foldable t, Monad m) => t (m a) -> m ()
-- | forM_ is mapM_ with its arguments flipped. For a version
-- that doesn't ignore the results see forM.
--
-- As of base 4.8.0.0, forM_ is just for_, specialized to
-- Monad.
forM_ :: (Foldable t, Monad m) => t a -> (a -> m b) -> m ()
-- | Map each element of a structure to a monadic action, evaluate these
-- actions from left to right, and ignore the results. For a version that
-- doesn't ignore the results see mapM.
--
-- As of base 4.8.0.0, mapM_ is just traverse_, specialized
-- to Monad.
mapM_ :: (Foldable t, Monad m) => (a -> m b) -> t a -> m ()
-- | void value discards or ignores the result of
-- evaluation, such as the return value of an IO action.
--
-- Using ApplicativeDo: 'void as' can be
-- understood as the do expression
--
--
-- do as
-- pure ()
--
--
-- with an inferred Functor constraint.
--
-- Examples
--
-- Replace the contents of a Maybe Int with unit:
--
--
-- >>> void Nothing
-- Nothing
--
-- >>> void (Just 3)
-- Just ()
--
--
-- Replace the contents of an Either Int
-- Int with unit, resulting in an Either
-- Int ():
--
--
-- >>> void (Left 8675309)
-- Left 8675309
--
-- >>> void (Right 8675309)
-- Right ()
--
--
-- Replace every element of a list with unit:
--
--
-- >>> void [1,2,3]
-- [(),(),()]
--
--
-- Replace the second element of a pair with unit:
--
--
-- >>> void (1,2)
-- (1,())
--
--
-- Discard the result of an IO action:
--
--
-- >>> mapM print [1,2]
-- 1
-- 2
-- [(),()]
--
-- >>> void $ mapM print [1,2]
-- 1
-- 2
--
void :: Functor f => f a -> f ()
-- | In many situations, the liftM operations can be replaced by
-- uses of ap, which promotes function application.
--
--
-- return f `ap` x1 `ap` ... `ap` xn
--
--
-- is equivalent to
--
--
-- liftMn f x1 x2 ... xn
--
ap :: Monad m => m (a -> b) -> m a -> m b
-- | Promote a function to a monad, scanning the monadic arguments from
-- left to right (cf. liftM2).
liftM5 :: Monad m => (a1 -> a2 -> a3 -> a4 -> a5 -> r) -> m a1 -> m a2 -> m a3 -> m a4 -> m a5 -> m r
-- | Promote a function to a monad, scanning the monadic arguments from
-- left to right (cf. liftM2).
liftM4 :: Monad m => (a1 -> a2 -> a3 -> a4 -> r) -> m a1 -> m a2 -> m a3 -> m a4 -> m r
-- | Promote a function to a monad, scanning the monadic arguments from
-- left to right (cf. liftM2).
liftM3 :: Monad m => (a1 -> a2 -> a3 -> r) -> m a1 -> m a2 -> m a3 -> m r
-- | Promote a function to a monad, scanning the monadic arguments from
-- left to right. For example,
--
--
-- liftM2 (+) [0,1] [0,2] = [0,2,1,3]
-- liftM2 (+) (Just 1) Nothing = Nothing
--
liftM2 :: Monad m => (a1 -> a2 -> r) -> m a1 -> m a2 -> m r
-- | Promote a function to a monad.
liftM :: Monad m => (a1 -> r) -> m a1 -> m r
-- | Conditional execution of Applicative expressions. For example,
--
--
-- when debug (putStrLn "Debugging")
--
--
-- will output the string Debugging if the Boolean value
-- debug is True, and otherwise do nothing.
when :: Applicative f => Bool -> f () -> f ()
-- | Same as >>=, but with the arguments interchanged.
(=<<) :: Monad m => (a -> m b) -> m a -> m b
infixr 1 =<<
-- | The character type Char is an enumeration whose values
-- represent Unicode (or equivalently ISO/IEC 10646) code points (i.e.
-- characters, see http://www.unicode.org/ for details). This set
-- extends the ISO 8859-1 (Latin-1) character set (the first 256
-- characters), which is itself an extension of the ASCII character set
-- (the first 128 characters). A character literal in Haskell has type
-- Char.
--
-- To convert a Char to or from the corresponding Int value
-- defined by Unicode, use toEnum and fromEnum from the
-- Enum class respectively (or equivalently ord and
-- chr).
data Char
-- | Convert a letter to the corresponding lower-case letter, if any. Any
-- other character is returned unchanged.
toLower :: Char -> Char
-- | Returns True for any Unicode space character, and the control
-- characters \t, \n, \r, \f,
-- \v.
isSpace :: Char -> Bool
-- | Selects alphabetic Unicode characters (lower-case, upper-case and
-- title-case letters, plus letters of caseless scripts and modifiers
-- letters). This function is equivalent to isLetter.
isAlpha :: Char -> Bool
-- | Selects ASCII digits, i.e. '0'..'9'.
isDigit :: Char -> Bool
-- | Selects Unicode space and separator characters.
--
-- This function returns True if its argument has one of the
-- following GeneralCategorys, or False otherwise:
--
--
--
-- These classes are defined in the Unicode Character Database,
-- part of the Unicode standard. The same document defines what is and is
-- not a "Separator".
--
-- Examples
--
-- Basic usage:
--
--
-- >>> isSeparator 'a'
-- False
--
-- >>> isSeparator '6'
-- False
--
-- >>> isSeparator ' '
-- True
--
--
-- Warning: newlines and tab characters are not considered separators.
--
--
-- >>> isSeparator '\n'
-- False
--
-- >>> isSeparator '\t'
-- False
--
--
-- But some more exotic characters are (like HTML's ):
--
--
-- >>> isSeparator '\160'
-- True
--
isSeparator :: Char -> Bool
-- | Selects Unicode numeric characters, including digits from various
-- scripts, Roman numerals, et cetera.
--
-- This function returns True if its argument has one of the
-- following GeneralCategorys, or False otherwise:
--
--
--
-- These classes are defined in the Unicode Character Database,
-- part of the Unicode standard. The same document defines what is and is
-- not a "Number".
--
-- Examples
--
-- Basic usage:
--
--
-- >>> isNumber 'a'
-- False
--
-- >>> isNumber '%'
-- False
--
-- >>> isNumber '3'
-- True
--
--
-- ASCII '0' through '9' are all numbers:
--
--
-- >>> and $ map isNumber ['0'..'9']
-- True
--
--
-- Unicode Roman numerals are "numbers" as well:
--
--
-- >>> isNumber 'Ⅸ'
-- True
--
isNumber :: Char -> Bool
-- | Selects Unicode mark characters, for example accents and the like,
-- which combine with preceding characters.
--
-- This function returns True if its argument has one of the
-- following GeneralCategorys, or False otherwise:
--
--
--
-- These classes are defined in the Unicode Character Database,
-- part of the Unicode standard. The same document defines what is and is
-- not a "Mark".
--
-- Examples
--
-- Basic usage:
--
--
-- >>> isMark 'a'
-- False
--
-- >>> isMark '0'
-- False
--
--
-- Combining marks such as accent characters usually need to follow
-- another character before they become printable:
--
--
-- >>> map isMark "ò"
-- [False,True]
--
--
-- Puns are not necessarily supported:
--
--
-- >>> isMark '✓'
-- False
--
isMark :: Char -> Bool
-- | Selects alphabetic Unicode characters (lower-case, upper-case and
-- title-case letters, plus letters of caseless scripts and modifiers
-- letters). This function is equivalent to isAlpha.
--
-- This function returns True if its argument has one of the
-- following GeneralCategorys, or False otherwise:
--
--
--
-- These classes are defined in the Unicode Character Database,
-- part of the Unicode standard. The same document defines what is and is
-- not a "Letter".
--
-- Examples
--
-- Basic usage:
--
--
-- >>> isLetter 'a'
-- True
--
-- >>> isLetter 'A'
-- True
--
-- >>> isLetter 'λ'
-- True
--
-- >>> isLetter '0'
-- False
--
-- >>> isLetter '%'
-- False
--
-- >>> isLetter '♥'
-- False
--
-- >>> isLetter '\31'
-- False
--
--
-- Ensure that isLetter and isAlpha are equivalent.
--
--
-- >>> let chars = [(chr 0)..]
--
-- >>> let letters = map isLetter chars
--
-- >>> let alphas = map isAlpha chars
--
-- >>> letters == alphas
-- True
--
isLetter :: Char -> Bool
-- | Convert a single digit Char to the corresponding Int.
-- This function fails unless its argument satisfies isHexDigit,
-- but recognises both upper- and lower-case hexadecimal digits (that is,
-- '0'..'9', 'a'..'f',
-- 'A'..'F').
--
-- Examples
--
-- Characters '0' through '9' are converted properly to
-- 0..9:
--
--
-- >>> map digitToInt ['0'..'9']
-- [0,1,2,3,4,5,6,7,8,9]
--
--
-- Both upper- and lower-case 'A' through 'F' are
-- converted as well, to 10..15.
--
--
-- >>> map digitToInt ['a'..'f']
-- [10,11,12,13,14,15]
--
-- >>> map digitToInt ['A'..'F']
-- [10,11,12,13,14,15]
--
--
-- Anything else throws an exception:
--
--
-- >>> digitToInt 'G'
-- *** Exception: Char.digitToInt: not a digit 'G'
--
-- >>> digitToInt '♥'
-- *** Exception: Char.digitToInt: not a digit '\9829'
--
digitToInt :: Char -> Int
-- | Read a string representation of a character, using Haskell
-- source-language escape conventions, and convert it to the character
-- that it encodes. For example:
--
--
-- readLitChar "\\nHello" = [('\n', "Hello")]
--
readLitChar :: ReadS Char
-- | Read a string representation of a character, using Haskell
-- source-language escape conventions. For example:
--
--
-- lexLitChar "\\nHello" = [("\\n", "Hello")]
--
lexLitChar :: ReadS String
-- | Convert a letter to the corresponding title-case or upper-case letter,
-- if any. (Title case differs from upper case only for a small number of
-- ligature letters.) Any other character is returned unchanged.
toTitle :: Char -> Char
-- | Convert a letter to the corresponding upper-case letter, if any. Any
-- other character is returned unchanged.
toUpper :: Char -> Char
-- | Selects lower-case alphabetic Unicode characters (letters).
isLower :: Char -> Bool
-- | Selects upper-case or title-case alphabetic Unicode characters
-- (letters). Title case is used by a small number of letter ligatures
-- like the single-character form of Lj.
isUpper :: Char -> Bool
-- | Selects printable Unicode characters (letters, numbers, marks,
-- punctuation, symbols and spaces).
isPrint :: Char -> Bool
-- | Selects control characters, which are the non-printing characters of
-- the Latin-1 subset of Unicode.
isControl :: Char -> Bool
-- | Selects alphabetic or numeric Unicode characters.
--
-- Note that numeric digits outside the ASCII range, as well as numeric
-- characters which aren't digits, are selected by this function but not
-- by isDigit. Such characters may be part of identifiers but are
-- not used by the printer and reader to represent numbers.
isAlphaNum :: Char -> Bool
-- | Selects Unicode symbol characters, including mathematical and currency
-- symbols.
--
-- This function returns True if its argument has one of the
-- following GeneralCategorys, or False otherwise:
--
--
--
-- These classes are defined in the Unicode Character Database,
-- part of the Unicode standard. The same document defines what is and is
-- not a "Symbol".
--
-- Examples
--
-- Basic usage:
--
--
-- >>> isSymbol 'a'
-- False
--
-- >>> isSymbol '6'
-- False
--
-- >>> isSymbol '='
-- True
--
--
-- The definition of "math symbol" may be a little counter-intuitive
-- depending on one's background:
--
--
-- >>> isSymbol '+'
-- True
--
-- >>> isSymbol '-'
-- False
--
isSymbol :: Char -> Bool
-- | Selects Unicode punctuation characters, including various kinds of
-- connectors, brackets and quotes.
--
-- This function returns True if its argument has one of the
-- following GeneralCategorys, or False otherwise:
--
--
--
-- These classes are defined in the Unicode Character Database,
-- part of the Unicode standard. The same document defines what is and is
-- not a "Punctuation".
--
-- Examples
--
-- Basic usage:
--
--
-- >>> isPunctuation 'a'
-- False
--
-- >>> isPunctuation '7'
-- False
--
-- >>> isPunctuation '♥'
-- False
--
-- >>> isPunctuation '"'
-- True
--
-- >>> isPunctuation '?'
-- True
--
-- >>> isPunctuation '—'
-- True
--
isPunctuation :: Char -> Bool
-- | Selects ASCII hexadecimal digits, i.e. '0'..'9',
-- 'a'..'f', 'A'..'F'.
isHexDigit :: Char -> Bool
-- | Selects ASCII octal digits, i.e. '0'..'7'.
isOctDigit :: Char -> Bool
-- | Selects ASCII upper-case letters, i.e. characters satisfying both
-- isAscii and isUpper.
isAsciiUpper :: Char -> Bool
-- | Selects ASCII lower-case letters, i.e. characters satisfying both
-- isAscii and isLower.
isAsciiLower :: Char -> Bool
-- | Selects the first 256 characters of the Unicode character set,
-- corresponding to the ISO 8859-1 (Latin-1) character set.
isLatin1 :: Char -> Bool
-- | Selects the first 128 characters of the Unicode character set,
-- corresponding to the ASCII character set.
isAscii :: Char -> Bool
-- | The Unicode general category of the character. This relies on the
-- Enum instance of GeneralCategory, which must remain in
-- the same order as the categories are presented in the Unicode
-- standard.
--
-- Examples
--
-- Basic usage:
--
--
-- >>> generalCategory 'a'
-- LowercaseLetter
--
-- >>> generalCategory 'A'
-- UppercaseLetter
--
-- >>> generalCategory '0'
-- DecimalNumber
--
-- >>> generalCategory '%'
-- OtherPunctuation
--
-- >>> generalCategory '♥'
-- OtherSymbol
--
-- >>> generalCategory '\31'
-- Control
--
-- >>> generalCategory ' '
-- Space
--
generalCategory :: Char -> GeneralCategory
-- | The toEnum method restricted to the type Char.
chr :: Int -> Char
-- | Convert an Int in the range 0..15 to the
-- corresponding single digit Char. This function fails on other
-- inputs, and generates lower-case hexadecimal digits.
intToDigit :: Int -> Char
-- | Convert a character to a string using only printable characters, using
-- Haskell source-language escape conventions. For example:
--
--
-- showLitChar '\n' s = "\\n" ++ s
--
showLitChar :: Char -> ShowS
-- | The fromEnum method restricted to the type Char.
ord :: Char -> Int
-- | The Data class comprehends a fundamental primitive
-- gfoldl for folding over constructor applications, say terms.
-- This primitive can be instantiated in several ways to map over the
-- immediate subterms of a term; see the gmap combinators later
-- in this class. Indeed, a generic programmer does not necessarily need
-- to use the ingenious gfoldl primitive but rather the intuitive
-- gmap combinators. The gfoldl primitive is completed by
-- means to query top-level constructors, to turn constructor
-- representations into proper terms, and to list all possible datatype
-- constructors. This completion allows us to serve generic programming
-- scenarios like read, show, equality, term generation.
--
-- The combinators gmapT, gmapQ, gmapM, etc are all
-- provided with default definitions in terms of gfoldl, leaving
-- open the opportunity to provide datatype-specific definitions. (The
-- inclusion of the gmap combinators as members of class
-- Data allows the programmer or the compiler to derive
-- specialised, and maybe more efficient code per datatype. Note:
-- gfoldl is more higher-order than the gmap combinators.
-- This is subject to ongoing benchmarking experiments. It might turn out
-- that the gmap combinators will be moved out of the class
-- Data.)
--
-- Conceptually, the definition of the gmap combinators in terms
-- of the primitive gfoldl requires the identification of the
-- gfoldl function arguments. Technically, we also need to
-- identify the type constructor c for the construction of the
-- result type from the folded term type.
--
-- In the definition of gmapQx combinators, we use
-- phantom type constructors for the c in the type of
-- gfoldl because the result type of a query does not involve the
-- (polymorphic) type of the term argument. In the definition of
-- gmapQl we simply use the plain constant type constructor
-- because gfoldl is left-associative anyway and so it is readily
-- suited to fold a left-associative binary operation over the immediate
-- subterms. In the definition of gmapQr, extra effort is needed. We use
-- a higher-order accumulation trick to mediate between left-associative
-- constructor application vs. right-associative binary operation (e.g.,
-- (:)). When the query is meant to compute a value of type
-- r, then the result type withing generic folding is r
-- -> r. So the result of folding is a function to which we
-- finally pass the right unit.
--
-- With the -XDeriveDataTypeable option, GHC can generate
-- instances of the Data class automatically. For example, given
-- the declaration
--
--
-- data T a b = C1 a b | C2 deriving (Typeable, Data)
--
--
-- GHC will generate an instance that is equivalent to
--
--
-- instance (Data a, Data b) => Data (T a b) where
-- gfoldl k z (C1 a b) = z C1 `k` a `k` b
-- gfoldl k z C2 = z C2
--
-- gunfold k z c = case constrIndex c of
-- 1 -> k (k (z C1))
-- 2 -> z C2
--
-- toConstr (C1 _ _) = con_C1
-- toConstr C2 = con_C2
--
-- dataTypeOf _ = ty_T
--
-- con_C1 = mkConstr ty_T "C1" [] Prefix
-- con_C2 = mkConstr ty_T "C2" [] Prefix
-- ty_T = mkDataType "Module.T" [con_C1, con_C2]
--
--
-- This is suitable for datatypes that are exported transparently.
class Typeable a => Data a
-- | Left-associative fold operation for constructor applications.
--
-- The type of gfoldl is a headache, but operationally it is a
-- simple generalisation of a list fold.
--
-- The default definition for gfoldl is const
-- id, which is suitable for abstract datatypes with no
-- substructures.
gfoldl :: Data a => (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. () => g -> c g) -> a -> c a
-- | Unfolding constructor applications
gunfold :: Data a => (forall b r. Data b => c (b -> r) -> c r) -> (forall r. () => r -> c r) -> Constr -> c a
-- | Obtaining the constructor from a given datum. For proper terms, this
-- is meant to be the top-level constructor. Primitive datatypes are here
-- viewed as potentially infinite sets of values (i.e., constructors).
toConstr :: Data a => a -> Constr
-- | The outer type constructor of the type
dataTypeOf :: Data a => a -> DataType
-- | Mediate types and unary type constructors.
--
-- In Data instances of the form
--
--
-- instance (Data a, ...) => Data (T a)
--
--
-- dataCast1 should be defined as gcast1.
--
-- The default definition is const Nothing, which
-- is appropriate for instances of other forms.
dataCast1 :: (Data a, Typeable t) => (forall d. Data d => c (t d)) -> Maybe (c a)
-- | Mediate types and binary type constructors.
--
-- In Data instances of the form
--
--
-- instance (Data a, Data b, ...) => Data (T a b)
--
--
-- dataCast2 should be defined as gcast2.
--
-- The default definition is const Nothing, which
-- is appropriate for instances of other forms.
dataCast2 :: (Data a, Typeable t) => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c a)
-- | A generic transformation that maps over the immediate subterms
--
-- The default definition instantiates the type constructor c in
-- the type of gfoldl to an identity datatype constructor, using
-- the isomorphism pair as injection and projection.
gmapT :: Data a => (forall b. Data b => b -> b) -> a -> a
-- | A generic query with a left-associative binary operator
gmapQl :: Data a => (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> a -> r
-- | A generic query with a right-associative binary operator
gmapQr :: forall r r'. Data a => (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> a -> r
-- | A generic query that processes the immediate subterms and returns a
-- list of results. The list is given in the same order as originally
-- specified in the declaration of the data constructors.
gmapQ :: Data a => (forall d. Data d => d -> u) -> a -> [u]
-- | A generic query that processes one child by index (zero-based)
gmapQi :: Data a => Int -> (forall d. Data d => d -> u) -> a -> u
-- | A generic monadic transformation that maps over the immediate subterms
--
-- The default definition instantiates the type constructor c in
-- the type of gfoldl to the monad datatype constructor, defining
-- injection and projection using return and >>=.
gmapM :: (Data a, Monad m) => (forall d. Data d => d -> m d) -> a -> m a
-- | Transformation of at least one immediate subterm does not fail
gmapMp :: (Data a, MonadPlus m) => (forall d. Data d => d -> m d) -> a -> m a
-- | Transformation of one immediate subterm with success
gmapMo :: (Data a, MonadPlus m) => (forall d. Data d => d -> m d) -> a -> m a
-- | The class Typeable allows a concrete representation of a type
-- to be calculated.
class Typeable (a :: k)
-- | on b u x y runs the binary function b
-- on the results of applying unary function u to two
-- arguments x and y. From the opposite perspective, it
-- transforms two inputs and combines the outputs.
--
--
-- ((+) `on` f) x y = f x + f y
--
--
-- Typical usage: sortBy (compare `on`
-- fst).
--
-- Algebraic properties:
--
--
-- (*) `on` id = (*) -- (if (*) ∉ {⊥, const
-- ⊥})((*) `on` f) `on` g = (*) `on` (f . g)
flip on f . flip on g = flip on (g .
-- f)
on :: (b -> b -> c) -> (a -> b) -> a -> a -> c
infixl 0 `on`
-- | The class of monoids (types with an associative binary operation that
-- has an identity). Instances should satisfy the following:
--
--
--
-- The method names refer to the monoid of lists under concatenation, but
-- there are many other instances.
--
-- Some types can be viewed as a monoid in more than one way, e.g. both
-- addition and multiplication on numbers. In such cases we often define
-- newtypes and make those instances of Monoid, e.g.
-- Sum and Product.
--
-- NOTE: Semigroup is a superclass of Monoid since
-- base-4.11.0.0.
class Semigroup a => Monoid a
-- | Identity of mappend
--
--
-- >>> "Hello world" <> mempty
-- "Hello world"
--
mempty :: Monoid a => a
-- | An associative operation
--
-- NOTE: This method is redundant and has the default
-- implementation mappend = (<>) since
-- base-4.11.0.0. Should it be implemented manually, since
-- mappend is a synonym for (<>), it is expected that
-- the two functions are defined the same way. In a future GHC release
-- mappend will be removed from Monoid.
mappend :: Monoid a => a -> a -> a
-- | Fold a list using the monoid.
--
-- For most types, the default definition for mconcat will be
-- used, but the function is included in the class definition so that an
-- optimized version can be provided for specific types.
--
--
-- >>> mconcat ["Hello", " ", "Haskell", "!"]
-- "Hello Haskell!"
--
mconcat :: Monoid a => [a] -> a
-- | Do any of the (monadic) predicates match?
anyM :: (Functor m, Applicative m, Monad m) => (a -> m Bool) -> [a] -> m Bool
-- | Alias of liftIO, I hate typing it. Hate reading it.
io :: MonadIO m => IO a -> m a
-- | Read from a process returning both std err and out.
readAllFromProcess :: FilePath -> [String] -> String -> IO (Either (String, String) (String, String))
-- | Configuring the compiler
module Fay.Config
-- | Configuration of the compiler. The fields with a leading underscore
data Config
defaultConfig :: Config
defaultConfigWithSandbox :: IO Config
-- | Reading _configDirectoryIncludes is safe to do.
configDirectoryIncludes :: Config -> [(Maybe String, FilePath)]
-- | Get all include directories without the package mapping.
configDirectoryIncludePaths :: Config -> [FilePath]
-- | Get all include directories not included through packages.
nonPackageConfigDirectoryIncludePaths :: Config -> [FilePath]
-- | Add a mapping from (maybe) a package to a source directory
addConfigDirectoryInclude :: Maybe String -> FilePath -> Config -> Config
-- | Add several include directories.
addConfigDirectoryIncludes :: [(Maybe String, FilePath)] -> Config -> Config
-- | Add several include directories without package references.
addConfigDirectoryIncludePaths :: [FilePath] -> Config -> Config
-- | Reading _configPackages is safe to do.
configPackages :: Config -> [String]
-- | Add a package to compilation
addConfigPackage :: String -> Config -> Config
-- | Add several packages to compilation
addConfigPackages :: [String] -> Config -> Config
-- | Should a strict wrapper be generated for this module?
shouldExportStrictWrapper :: ModuleName a -> Config -> Bool
instance GHC.Show.Show Fay.Config.Config
instance Data.Default.Class.Default Fay.Config.Config
-- | Convert a Haskell value to a (JSON representation of a) Fay value.
module Fay.Convert
-- | Convert a Haskell value to a Fay json value. This can fail when
-- primitive values aren't handled by explicit cases. encodeFay
-- can be used to resolve this issue.
showToFay :: Data a => a -> Maybe Value
-- | Convert a Fay json value to a Haskell value.
readFromFay :: Data a => Value -> Maybe a
-- | Convert a Fay json value to a Haskell value. This is like readFromFay,
-- except it yields helpful error messages on failure.
readFromFay' :: Data a => Value -> Either String a
-- | Convert a Haskell value to a Fay json value. This can fail when
-- primitive values aren't handled by explicit cases. When this happens,
-- you can add additional cases via the first parameter.
--
-- The first parameter is a function that can be used to override the
-- conversion. This usually looks like using extQ to additional
-- type- specific cases.
encodeFay :: (GenericQ Value -> GenericQ Value) -> GenericQ Value
-- | Convert a Fay json value to a Haskell value.
--
-- The first parameter is a function that can be used to override the
-- conversion. This usually looks like using extR to additional
-- type- specific cases.
decodeFay :: Data b => (forall a. Data a => Value -> Either String a -> Either String a) -> Value -> Either String b
module Fay.Types.CompileResult
data CompileResult
CompileResult :: String -> [(String, FilePath)] -> Maybe [Mapping] -> CompileResult
[resOutput] :: CompileResult -> String
[resImported] :: CompileResult -> [(String, FilePath)]
[resSourceMappings] :: CompileResult -> Maybe [Mapping]
instance GHC.Show.Show Fay.Types.CompileResult.CompileResult
module Fay.Types.CompileError
-- | Error type.
data CompileError
Couldn'tFindImport :: ModuleName -> [FilePath] -> CompileError
EmptyDoBlock :: CompileError
FfiFormatBadChars :: SrcSpanInfo -> String -> CompileError
FfiFormatIncompleteArg :: SrcSpanInfo -> CompileError
FfiFormatInvalidJavaScript :: SrcSpanInfo -> String -> String -> CompileError
FfiFormatNoSuchArg :: SrcSpanInfo -> Int -> CompileError
FfiNeedsTypeSig :: Exp -> CompileError
GHCError :: String -> CompileError
InvalidDoBlock :: CompileError
ParseError :: SrcLoc -> String -> CompileError
ShouldBeDesugared :: String -> CompileError
UnableResolveQualified :: QName -> CompileError
UnsupportedDeclaration :: Decl -> CompileError
UnsupportedEnum :: Exp -> CompileError
UnsupportedExportSpec :: ExportSpec -> CompileError
UnsupportedExpression :: Exp -> CompileError
UnsupportedFieldPattern :: PatField -> CompileError
UnsupportedImport :: ImportDecl -> CompileError
UnsupportedLet :: CompileError
UnsupportedLetBinding :: Decl -> CompileError
UnsupportedLiteral :: Literal -> CompileError
UnsupportedModuleSyntax :: String -> Module -> CompileError
UnsupportedPattern :: Pat -> CompileError
UnsupportedQualStmt :: QualStmt -> CompileError
UnsupportedRecursiveDo :: CompileError
UnsupportedRhs :: Rhs -> CompileError
UnsupportedWhereInAlt :: Alt -> CompileError
UnsupportedWhereInMatch :: Match -> CompileError
instance GHC.Show.Show Fay.Types.CompileError.CompileError
-- | All Fay types and instances.
module Fay.Types
-- | Statement type.
data JsStmt
JsVar :: JsName -> JsExp -> JsStmt
JsMapVar :: JsName -> JsExp -> JsStmt
JsIf :: JsExp -> [JsStmt] -> [JsStmt] -> JsStmt
JsEarlyReturn :: JsExp -> JsStmt
JsThrow :: JsExp -> JsStmt
JsWhile :: JsExp -> [JsStmt] -> JsStmt
JsUpdate :: JsName -> JsExp -> JsStmt
JsSetProp :: JsName -> JsName -> JsExp -> JsStmt
JsSetQName :: Maybe SrcSpan -> QName -> JsExp -> JsStmt
JsSetModule :: ModulePath -> JsExp -> JsStmt
JsSetConstructor :: QName -> JsExp -> JsStmt
JsSetPropExtern :: JsName -> JsName -> JsExp -> JsStmt
JsContinue :: JsStmt
JsBlock :: [JsStmt] -> JsStmt
JsExpStmt :: JsExp -> JsStmt
-- | Expression type.
data JsExp
JsName :: JsName -> JsExp
JsRawExp :: String -> JsExp
JsSeq :: [JsExp] -> JsExp
JsFun :: Maybe JsName -> [JsName] -> [JsStmt] -> Maybe JsExp -> JsExp
JsLit :: JsLit -> JsExp
JsApp :: JsExp -> [JsExp] -> JsExp
JsNegApp :: JsExp -> JsExp
JsTernaryIf :: JsExp -> JsExp -> JsExp -> JsExp
JsNull :: JsExp
JsParen :: JsExp -> JsExp
JsGetProp :: JsExp -> JsName -> JsExp
JsLookup :: JsExp -> JsExp -> JsExp
JsUpdateProp :: JsExp -> JsName -> JsExp -> JsExp
JsGetPropExtern :: JsExp -> String -> JsExp
JsUpdatePropExtern :: JsExp -> JsName -> JsExp -> JsExp
JsList :: [JsExp] -> JsExp
JsNew :: JsName -> [JsExp] -> JsExp
JsThrowExp :: JsExp -> JsExp
JsInstanceOf :: JsExp -> JsName -> JsExp
JsIndex :: Int -> JsExp -> JsExp
JsEq :: JsExp -> JsExp -> JsExp
JsNeq :: JsExp -> JsExp -> JsExp
JsInfix :: String -> JsExp -> JsExp -> JsExp
JsObj :: [(String, JsExp)] -> JsExp
JsLitObj :: [(Name, JsExp)] -> JsExp
JsUndefined :: JsExp
JsAnd :: JsExp -> JsExp -> JsExp
JsOr :: JsExp -> JsExp -> JsExp
-- | Literal value type.
data JsLit
JsChar :: Char -> JsLit
JsStr :: String -> JsLit
JsInt :: Int -> JsLit
JsFloating :: Double -> JsLit
JsBool :: Bool -> JsLit
-- | A name of some kind.
data JsName
JsNameVar :: QName -> JsName
JsThis :: JsName
JsParametrizedType :: JsName
JsThunk :: JsName
JsForce :: JsName
JsApply :: JsName
JsParam :: Integer -> JsName
JsTmp :: Integer -> JsName
JsConstructor :: QName -> JsName
JsBuiltIn :: Name -> JsName
JsModuleName :: ModuleName -> JsName
-- | Error type.
data CompileError
Couldn'tFindImport :: ModuleName -> [FilePath] -> CompileError
EmptyDoBlock :: CompileError
FfiFormatBadChars :: SrcSpanInfo -> String -> CompileError
FfiFormatIncompleteArg :: SrcSpanInfo -> CompileError
FfiFormatInvalidJavaScript :: SrcSpanInfo -> String -> String -> CompileError
FfiFormatNoSuchArg :: SrcSpanInfo -> Int -> CompileError
FfiNeedsTypeSig :: Exp -> CompileError
GHCError :: String -> CompileError
InvalidDoBlock :: CompileError
ParseError :: SrcLoc -> String -> CompileError
ShouldBeDesugared :: String -> CompileError
UnableResolveQualified :: QName -> CompileError
UnsupportedDeclaration :: Decl -> CompileError
UnsupportedEnum :: Exp -> CompileError
UnsupportedExportSpec :: ExportSpec -> CompileError
UnsupportedExpression :: Exp -> CompileError
UnsupportedFieldPattern :: PatField -> CompileError
UnsupportedImport :: ImportDecl -> CompileError
UnsupportedLet :: CompileError
UnsupportedLetBinding :: Decl -> CompileError
UnsupportedLiteral :: Literal -> CompileError
UnsupportedModuleSyntax :: String -> Module -> CompileError
UnsupportedPattern :: Pat -> CompileError
UnsupportedQualStmt :: QualStmt -> CompileError
UnsupportedRecursiveDo :: CompileError
UnsupportedRhs :: Rhs -> CompileError
UnsupportedWhereInAlt :: Alt -> CompileError
UnsupportedWhereInMatch :: Match -> CompileError
-- | Compile monad.
newtype Compile a
Compile :: RWST CompileReader CompileWriter CompileState (ExceptT CompileError (ModuleT (ModuleInfo Compile) IO)) a -> Compile a
-- | Uns the compiler
[unCompile] :: Compile a -> RWST CompileReader CompileWriter CompileState (ExceptT CompileError (ModuleT (ModuleInfo Compile) IO)) a
type CompileModule a = ModuleT Symbols IO (Either CompileError (a, CompileState, CompileWriter))
-- | Print some value.
class Printable a
printJS :: Printable a => a -> Printer
-- | The JavaScript FFI interfacing monad.
data Fay a
-- | Configuration and globals for the compiler.
data CompileReader
CompileReader :: Config -> (Sign -> Literal -> Compile JsExp) -> (Bool -> [Decl] -> Compile [JsStmt]) -> CompileReader
-- | The compilation configuration.
[readerConfig] :: CompileReader -> Config
[readerCompileLit] :: CompileReader -> Sign -> Literal -> Compile JsExp
[readerCompileDecls] :: CompileReader -> Bool -> [Decl] -> Compile [JsStmt]
data CompileResult
CompileResult :: String -> [(String, FilePath)] -> Maybe [Mapping] -> CompileResult
[resOutput] :: CompileResult -> String
[resImported] :: CompileResult -> [(String, FilePath)]
[resSourceMappings] :: CompileResult -> Maybe [Mapping]
-- | Things written out by the compiler.
data CompileWriter
CompileWriter :: [JsStmt] -> [(String, JsExp)] -> [(String, JsExp)] -> CompileWriter
-- | Constructors.
[writerCons] :: CompileWriter -> [JsStmt]
-- | Fay to JS dispatchers.
[writerFayToJs] :: CompileWriter -> [(String, JsExp)]
-- | JS to Fay dispatchers.
[writerJsToFay] :: CompileWriter -> [(String, JsExp)]
-- | Configuration of the compiler. The fields with a leading underscore
data Config
-- | State of the compiler.
data CompileState
CompileState :: Map ModuleName Symbols -> [(QName, [QName])] -> [(QName, [Name])] -> [(QName, Maybe QName, Type)] -> [(ModuleName, FilePath)] -> Integer -> ModuleName -> Set ModulePath -> Bool -> Map QName Type -> CompileState
-- | Exported identifiers for all modules
[stateInterfaces] :: CompileState -> Map ModuleName Symbols
-- | Map types to constructors
[stateRecordTypes] :: CompileState -> [(QName, [QName])]
-- | Map constructors to fields
[stateRecords] :: CompileState -> [(QName, [Name])]
-- | Newtype constructor, destructor, wrapped type tuple
[stateNewtypes] :: CompileState -> [(QName, Maybe QName, Type)]
-- | Map of all imported modules and their source locations.
[stateImported] :: CompileState -> [(ModuleName, FilePath)]
-- | Depth of the current lexical scope, used for creating unshadowing
-- variables.
[stateNameDepth] :: CompileState -> Integer
-- | Name of the module currently being compiled.
[stateModuleName] :: CompileState -> ModuleName
-- | Module paths that have code generated for them.
[stateJsModulePaths] :: CompileState -> Set ModulePath
-- | Use JS Strings instead of [Char] for string literals?
[stateUseFromString] :: CompileState -> Bool
-- | Module level declarations having explicit type signatures
[stateTypeSigs] :: CompileState -> Map QName Type
-- | These are the data types that are serializable directly to native JS
-- data types. Strings, floating points and arrays. The others are:
-- actions in the JS monad, which are thunks that shouldn't be forced
-- when serialized but wrapped up as JS zero-arg functions, and unknown
-- types can't be converted but should at least be forced.
data FundamentalType
FunctionType :: [FundamentalType] -> FundamentalType
JsType :: FundamentalType -> FundamentalType
ListType :: FundamentalType -> FundamentalType
TupleType :: [FundamentalType] -> FundamentalType
UserDefined :: Name -> [FundamentalType] -> FundamentalType
Defined :: FundamentalType -> FundamentalType
Nullable :: FundamentalType -> FundamentalType
DateType :: FundamentalType
StringType :: FundamentalType
DoubleType :: FundamentalType
IntType :: FundamentalType
BoolType :: FundamentalType
PtrType :: FundamentalType
Automatic :: FundamentalType
UnknownType :: FundamentalType
-- | The state of the pretty printer.
data PrintState
PrintState :: Int -> Int -> Int -> Bool -> PrintState
-- | The current line.
[psLine] :: PrintState -> Int
-- | Current column.
[psColumn] :: PrintState -> Int
-- | Current indentation level.
[psIndentLevel] :: PrintState -> Int
-- | Just outputted a newline?
[psNewline] :: PrintState -> Bool
-- | Default state.
defaultPrintState :: PrintState
-- | Global options of the printer
data PrintReader
PrintReader :: Bool -> Bool -> Bool -> PrintReader
-- | Are we to pretty print?
[prPretty] :: PrintReader -> Bool
-- | Use pretty thunk names?
[prPrettyThunks] :: PrintReader -> Bool
-- | Use pretty operators?
[prPrettyOperators] :: PrintReader -> Bool
-- | default printer options (non-pretty printing)
defaultPrintReader :: PrintReader
-- | Output of printer
data PrintWriter
PrintWriter :: [Mapping] -> ShowS -> PrintWriter
-- | Source mappings.
[pwMappings] :: PrintWriter -> [Mapping]
-- | The current output.
[pwOutput] :: PrintWriter -> ShowS
pwOutputString :: PrintWriter -> String
-- | The printer.
newtype Printer
Printer :: RWS PrintReader PrintWriter PrintState () -> Printer
[runPrinter] :: Printer -> RWS PrintReader PrintWriter PrintState ()
execPrinter :: Printer -> PrintReader -> PrintWriter
-- | Print the given printer indented.
indented :: Printer -> Printer
-- | exec one of Printers depending on PrintReader property.
askIf :: (PrintReader -> Bool) -> Printer -> Printer -> Printer
-- | Output a newline and makes next line indented when prPretty is True.
-- Does nothing when prPretty is False
newline :: Printer
-- | Write out a raw string, respecting the indentation Note: if you pass a
-- string with newline characters, it will print them out even if
-- prPretty is set to False. Also next line won't be indented. If you
-- want write a smart newline (that is the one which will be written out
-- only if prPretty is true, and after which the line will be indented)
-- use newline)
write :: String -> Printer
-- | Generate a mapping from the Haskell location to the current point in
-- the output.
mapping :: SrcSpan -> Printer
-- | The serialization context indicates whether we're currently
-- serializing some value or a particular field in a user-defined data
-- type.
data SerializeContext
SerializeAnywhere :: SerializeContext
SerializeUserArg :: Int -> SerializeContext
-- | The name of a module split into a list for code generation.
data ModulePath
-- | Construct the complete ModulePath from a ModuleName.
mkModulePath :: ModuleName a -> ModulePath
-- | Construct intermediate module paths from a ModuleName. mkModulePaths
-- A.B => [[A], [A,B]]
mkModulePaths :: ModuleName a -> [ModulePath]
-- | Converting a QName to a ModulePath is only relevant for constructors
-- since they can conflict with module names.
mkModulePathFromQName :: QName a -> ModulePath
instance GHC.Show.Show Fay.Types.CompileState
instance GHC.Show.Show Fay.Types.CompileWriter
instance Control.Monad.Writer.Class.MonadWriter Fay.Types.CompileWriter Fay.Types.Compile
instance Control.Monad.State.Class.MonadState Fay.Types.CompileState Fay.Types.Compile
instance Control.Monad.Reader.Class.MonadReader Fay.Types.CompileReader Fay.Types.Compile
instance Control.Monad.IO.Class.MonadIO Fay.Types.Compile
instance Control.Monad.Error.Class.MonadError Fay.Types.CompileError.CompileError Fay.Types.Compile
instance GHC.Base.Monad Fay.Types.Compile
instance GHC.Base.Functor Fay.Types.Compile
instance GHC.Base.Applicative Fay.Types.Compile
instance GHC.Base.Monad Fay.Types.Fay
instance GHC.Base.Functor Fay.Types.Fay
instance GHC.Base.Applicative Fay.Types.Fay
instance Fay.Compiler.ModuleT.MonadModule Fay.Types.Compile
instance GHC.Base.Semigroup Fay.Types.CompileWriter
instance GHC.Base.Monoid Fay.Types.CompileWriter
-- | The internal FFI module.
module Fay.FFI
-- | The JavaScript FFI interfacing monad.
data Fay a
-- | Values that may be null Nullable x decodes to x, Null decodes to null.
data Nullable a
Nullable :: a -> Nullable a
Null :: Nullable a
-- | Values that may be undefined Defined x encodes to x, Undefined decodes
-- to undefined. An undefined property in a record will be removed when
-- encoding.
data Defined a
Defined :: a -> Defined a
Undefined :: Defined a
-- | Do not serialize the specified type. This is useful for, e.g.
--
--
-- foo :: String -> String
-- foo = ffi "%1"
--
--
-- This would normally serialize and unserialize the string, for no
-- reason, in this case. Instead:
--
--
-- foo :: Ptr String -> Ptr String
--
--
-- Will just give an identity function.
type Ptr a = a
-- | The opposite of Ptr. Serialize the specified polymorphic type.
--
--
-- foo :: Automatic a -> String
--
type Automatic a = a
-- | Declare a foreign action.
ffi :: IsString s => s -> a
-- | Desugars a reasonable amount of syntax to reduce duplication in code
-- generation.
module Fay.Compiler.Desugar
-- | Top level, desugar a whole module possibly returning errors
desugar :: (Data l, Typeable l) => l -> Module l -> IO (Either CompileError (Module l))
-- | Desugar with the option to specify a prefix for generated names.
-- Useful if you want to provide valid haskell names that HSE can print.
desugar' :: (Data l, Typeable l) => String -> l -> Module l -> IO (Either CompileError (Module l))
-- | (a) => a for patterns
desugarExpParen :: (Data l, Typeable l) => Module l -> Module l
desugarPatParen :: (Data l, Typeable l) => Module l -> Module l
-- | The Haskell→Javascript compiler.
module Fay.Compiler
-- | Runs compilation for a single module.
runCompileModule :: CompileReader -> CompileState -> Compile a -> CompileModule a
-- | Compile a Haskell source string to a JavaScript source string.
compileViaStr :: FilePath -> Config -> (Module -> Compile [JsStmt]) -> String -> IO (Either CompileError (Printer, CompileState, CompileWriter))
-- | Compile a module
compileWith :: (Monoid a, Semigroup a) => FilePath -> (a -> Module -> Compile a) -> (FilePath -> String -> Compile a) -> (X -> Module -> IO (Either CompileError Module)) -> String -> Compile (a, CompileState, CompileWriter)
-- | Compile Haskell expression.
compileExp :: Exp -> Compile JsExp
-- | Compile a declaration.
compileDecl :: Bool -> Decl -> Compile [JsStmt]
-- | Compile the top-level Fay module.
compileToplevelModule :: FilePath -> Module -> Compile [JsStmt]
-- | Compile a source string.
compileModuleFromContents :: String -> Compile ([JsStmt], [JsStmt])
-- | Compile a parse HSE module.
compileModuleFromAST :: ([JsStmt], [JsStmt]) -> Module -> Compile ([JsStmt], [JsStmt])
-- | Parse some Fay code.
parseFay :: Parseable ast => FilePath -> String -> ParseResult ast
-- | Main library entry point.
module Fay
-- | Error type.
data CompileError
Couldn'tFindImport :: ModuleName -> [FilePath] -> CompileError
EmptyDoBlock :: CompileError
FfiFormatBadChars :: SrcSpanInfo -> String -> CompileError
FfiFormatIncompleteArg :: SrcSpanInfo -> CompileError
FfiFormatInvalidJavaScript :: SrcSpanInfo -> String -> String -> CompileError
FfiFormatNoSuchArg :: SrcSpanInfo -> Int -> CompileError
FfiNeedsTypeSig :: Exp -> CompileError
GHCError :: String -> CompileError
InvalidDoBlock :: CompileError
ParseError :: SrcLoc -> String -> CompileError
ShouldBeDesugared :: String -> CompileError
UnableResolveQualified :: QName -> CompileError
UnsupportedDeclaration :: Decl -> CompileError
UnsupportedEnum :: Exp -> CompileError
UnsupportedExportSpec :: ExportSpec -> CompileError
UnsupportedExpression :: Exp -> CompileError
UnsupportedFieldPattern :: PatField -> CompileError
UnsupportedImport :: ImportDecl -> CompileError
UnsupportedLet :: CompileError
UnsupportedLetBinding :: Decl -> CompileError
UnsupportedLiteral :: Literal -> CompileError
UnsupportedModuleSyntax :: String -> Module -> CompileError
UnsupportedPattern :: Pat -> CompileError
UnsupportedQualStmt :: QualStmt -> CompileError
UnsupportedRecursiveDo :: CompileError
UnsupportedRhs :: Rhs -> CompileError
UnsupportedWhereInAlt :: Alt -> CompileError
UnsupportedWhereInMatch :: Match -> CompileError
-- | State of the compiler.
data CompileState
CompileState :: Map ModuleName Symbols -> [(QName, [QName])] -> [(QName, [Name])] -> [(QName, Maybe QName, Type)] -> [(ModuleName, FilePath)] -> Integer -> ModuleName -> Set ModulePath -> Bool -> Map QName Type -> CompileState
-- | Exported identifiers for all modules
[stateInterfaces] :: CompileState -> Map ModuleName Symbols
-- | Map types to constructors
[stateRecordTypes] :: CompileState -> [(QName, [QName])]
-- | Map constructors to fields
[stateRecords] :: CompileState -> [(QName, [Name])]
-- | Newtype constructor, destructor, wrapped type tuple
[stateNewtypes] :: CompileState -> [(QName, Maybe QName, Type)]
-- | Map of all imported modules and their source locations.
[stateImported] :: CompileState -> [(ModuleName, FilePath)]
-- | Depth of the current lexical scope, used for creating unshadowing
-- variables.
[stateNameDepth] :: CompileState -> Integer
-- | Name of the module currently being compiled.
[stateModuleName] :: CompileState -> ModuleName
-- | Module paths that have code generated for them.
[stateJsModulePaths] :: CompileState -> Set ModulePath
-- | Use JS Strings instead of [Char] for string literals?
[stateUseFromString] :: CompileState -> Bool
-- | Module level declarations having explicit type signatures
[stateTypeSigs] :: CompileState -> Map QName Type
data CompileResult
CompileResult :: String -> [(String, FilePath)] -> Maybe [Mapping] -> CompileResult
[resOutput] :: CompileResult -> String
[resImported] :: CompileResult -> [(String, FilePath)]
[resSourceMappings] :: CompileResult -> Maybe [Mapping]
-- | Compile the given file.
compileFile :: Config -> FilePath -> IO (Either CompileError String)
-- | Compile a file returning the resulting internal state of the compiler.
-- Don't use this directly, it's only exposed for the test suite.
compileFileWithState :: Config -> FilePath -> IO (Either CompileError (String, Maybe [Mapping], CompileState))
-- | Compile a file returning additional generated metadata.
compileFileWithResult :: Config -> FilePath -> IO (Either CompileError CompileResult)
-- | Compile the given file and write the output to the given path, or if
-- nothing given, stdout.
compileFromTo :: Config -> FilePath -> Maybe FilePath -> IO ()
-- | Compile the given file and write to the output, also generates HTML
-- and sourcemap files if configured.
compileFromToAndGenerateHtml :: Config -> FilePath -> FilePath -> IO (Either CompileError String)
-- | Convert a Haskell filename to a JS filename.
toJsName :: String -> String
-- | Convert a Haskell filename to a TypeScript filename.
toTsName :: String -> String
-- | Print a compile error for human consumption.
showCompileError :: CompileError -> String
-- | Get the JS runtime source. This will return the user supplied runtime
-- if it exists.
readConfigRuntime :: Config -> IO String