What is "|>" for in Elixir?

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Reading some codes from I see |> be used commonly. What it means?

elixir

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The symbol |> is known as the pipe operator. The pipe operator |> is something extremely useful and will certainly improve the readability of your code with Elixir.

It basically takes the output of the left expression and passes as the first argument of a function on the right.

Let’s say I’m not aware of the pipe operator and want to multiply all values of a list by two, then filter those that are greater than 4, our code will be as follows:

lista = [1, 2 , 3]
Enum.filter(Enum.map(lista, &(&1 * 2)), &(&1 > 4))

If we use the pipe operator, our example will be different:

lista = [1, 2, 3]
# A lista gerada no primeiro map será o primeiro parametro do filter
Enum.map(lista, &(&1 * 2)) |> Enum.filter(&(&1 > 4))

Or even, in the iex:

[1, 2, 3] |> Enum.map(&(&1 * 2))  |> Enum.filter(&(&1 > 4))

And in an archive:

[1, 2, 3] 
|> Enum.map(&(&1 * 2))  
|> Enum.filter(&(&1 > 4))

You can read more about the pipe operator and other language features in official documentation and in the elixirschool

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