Data.Function
#flip
flip :: forall a b c. (a -> b -> c) -> b -> a -> c
Flips the order of the arguments to a function of two arguments.
flip const 1 2 = const 2 1 = 2
#const
const :: forall a b. a -> b -> a
Returns its first argument and ignores its second.
const 1 "hello" = 1
#apply
apply :: forall a b. (a -> b) -> a -> b
Applies a function to an argument. This is primarily used as the operator
($)
which allows parentheses to be omitted in some cases, or as a
natural way to apply a chain of composed functions to a value.
#($)
Operator alias for Data.Function.apply (right-associative / precedence 0)
Applies a function to an argument: the reverse of (#)
.
length $ groupBy productCategory $ filter isInStock $ products
is equivalent to:
length (groupBy productCategory (filter isInStock products))
Or another alternative equivalent, applying chain of composed functions to a value:
length <<< groupBy productCategory <<< filter isInStock $ products
#applyFlipped
applyFlipped :: forall a b. a -> (a -> b) -> b
Applies an argument to a function. This is primarily used as the (#)
operator, which allows parentheses to be ommitted in some cases, or as a
natural way to apply a value to a chain of composed functions.
#(#)
Operator alias for Data.Function.applyFlipped (left-associative / precedence 1)
Applies an argument to a function: the reverse of ($)
.
products # filter isInStock # groupBy productCategory # length
is equivalent to:
length (groupBy productCategory (filter isInStock products))
Or another alternative equivalent, applying a value to a chain of composed functions:
products # filter isInStock >>> groupBy productCategory >>> length
#applyN
#on
on :: forall a b c. (b -> b -> c) -> (a -> b) -> a -> a -> c
The on
function is used to change the domain of a binary operator.
For example, we can create a function which compares two records based on the values of their x
properties:
compareX :: forall r. { x :: Number | r } -> { x :: Number | r } -> Ordering
compareX = compare `on` _.x
Re-exports from Control.Category
#compose
compose :: forall b c d a. Semigroupoid a => a c d -> a b c -> a b d
#(>>>)
Operator alias for Control.Semigroupoid.composeFlipped (right-associative / precedence 9)
#(<<<)
Operator alias for Control.Semigroupoid.compose (right-associative / precedence 9)
Modules
- Control.Applicative
- Control.Apply
- Control.Bind
- Control.Category
- Control.Monad
- Control.Semigroupoid
- Data.Boolean
- Data.BooleanAlgebra
- Data.Bounded
- Data.CommutativeRing
- Data.DivisionRing
- Data.Eq
- Data.EuclideanRing
- Data.Field
- Data.Function
- Data.Functor
- Data.HeytingAlgebra
- Data.Monoid
- Data.Monoid.Additive
- Data.Monoid.Conj
- Data.Monoid.Disj
- Data.Monoid.Dual
- Data.Monoid.Endo
- Data.Monoid.Multiplicative
- Data.NaturalTransformation
- Data.Ord
- Data.Ord.Unsafe
- Data.Ordering
- Data.Ring
- Data.Semigroup
- Data.Semigroup.First
- Data.Semigroup.Last
- Data.Semiring
- Data.Show
- Data.Symbol
- Data.Unit
- Data.Void
- Effect
- Effect.Class
- Effect.Class.Console
- Effect.Console
- Effect.Uncurried
- Effect.Unsafe
- Main
- PSCI.Support
- Prelude
- Prim
- Prim.Ordering
- Prim.Row
- Prim.RowList
- Prim.Symbol
- Prim.TypeError
- Record.Unsafe
- Type.Data.Boolean
- Type.Data.Ordering
- Type.Data.Row
- Type.Data.RowList
- Type.Data.Symbol
- Type.Equality
- Type.Prelude
- Type.Proxy
- Type.Row
- Type.Row.Homogeneous