Safe Haskell	Safe

Eta.Core

Description

Synopsis

Documentation

>>> import Eta.Classes.Num
>>> import Eta.Classes.Functor
>>> import Eta.Classes.Show
>>> import Eta.Types.IO

(|>) :: a -> (a -> b) -> b #

Pipe operator. Functions can be applied using the pipe operator, reducing parentheses and increasing the code readability.

Instead of writing

  (printLine (join ", " (sort names)))

Use the pipe operator:

  names
    |> sort
    |> join ", "
    |> printLine

(<|) :: (a -> b) -> a -> b #

Pipe backwards operator. Applies the function of the left to the value of the right.

>>> (+ 2) <| 1
3

($) :: (a -> b) -> a -> b #

Application operator. Synonymous to (<|), useful for skipping a level of parentheses.

It can be read as "enclose in parentheses from here to the end of the expression."

>>> (print $ show 4)
4

flip :: (a -> b -> c) -> b -> a -> c #

Flips the arguments of a function

>>> subtract a b = a - b
>>> inverseSubtract = flip subtract
>>> subtract 3 2
1
>>> inverseSubtract 3 2
-1

Warning: Partial functions should be avoided

Stops execution and displays an error message.

Warning: Partial functions should be avoided

A value that can be of any type. The compiler will recognize this and insert an error message appropriate to the context where it appears.

Usually, also called Bottom

Returns undefined if a is undefined, otherwise returns b

>>> stopIfUndefined 1 2
2

constantly :: a -> b -> a #

Constructs a function that returns the same output for the same input

>>> universe = constantly 42
>>> universe 35
42
>>> map (constantly 10) [1..3]
[10,10,10]