Function.identity

You're seeing just the function identity, go back to Function module for more information.
Link to this function

identity(value)

View Source (since 1.10.0)

Specs

identity(value) :: value when value: var

Returns its input value. This function can be passed as an anonymous function to transformation functions.

Examples

iex> Function.identity("Hello world!")
"Hello world!"

iex> 'abcdaabccc' |> Enum.sort() |> Enum.chunk_by(&Function.identity/1)
['aaa', 'bb', 'cccc', 'd']

iex> Enum.group_by('abracadabra', &Function.identity/1)
%{97 => 'aaaaa', 98 => 'bb', 99 => 'c', 100 => 'd', 114 => 'rr'}

iex> Enum.map([1, 2, 3, 4], &Function.identity/1)
[1, 2, 3, 4]