Anonymous Functions

import IEx.Helpers

Anonymous Function

# format of anonymous function
# fn x -> x +1 end
inc = fn x -> x + 1 end

#Function<42.105768164/1 in :erl_eval.expr/6>

i(inc)

Term
  #Function<42.105768164/1 in :erl_eval.expr/6>
Data type
  Function
Type
  local
Arity
  1
Description
  This is an anonymous function.
Implemented protocols
  Enumerable, IEx.Info, Inspect

inc.(42)

43

func2 = &IO.inspect/1

&IO.inspect/1

i(func2)

Term
  &IO.inspect/1
Data type
  Function
Type
  external
Arity
  1
Implemented protocols
  Enumerable, IEx.Info, Inspect

func2.(42)

42

42

h(Enum.map())

                            def map(enumerable, fun)                            

  @spec map(t(), (element() -> any())) :: list()

Returns a list where each element is the result of invoking fun on each
corresponding element of enumerable.

For maps, the function expects a key-value tuple.

## Examples

    iex> Enum.map([1, 2, 3], fn x -> x * 2 end)
    [2, 4, 6]
    
    iex> Enum.map([a: 1, b: 2], fn {k, v} -> {k, -v} end)
    [a: -1, b: -2]

Enum.map([1, 2, 3], fn x -> x * x end)

[1, 4, 9]

Enum.map([1, 2, 3], fn x ->
  x * x
end)

[1, 4, 9]

Enum.map(
  [1, 2, 3],
  fn x ->
    x * x
  end
)

[1, 4, 9]