published on in elixir
tags: elixir capture copy operator anonymous

Elixir capture(&) command

I intend to explain the usage of the capture (&) command in elixir for newbies like myself, base on my understanding at this point :). It is barely 2 weeks since I started writing elixir as at the writing of this post, coming from node.js.

The first time I came across the syntax below, I wondered what the f**k is happening here, but I after a while I grab it, thanks to google. :)

iex(1)> {:ok, %{name: "bla bla"}} |> (& {:ok, %{}} = &1).()
{:ok, %{name: "bla bla"}}


In the code above the right side is being pattern matched to the left side.

The left side {:ok, %{name: "bla bla"}} is piped (|>) to the match using the capture symbol & and the output is giving to right side of my match = &1.

The trick here is that the capture symbol & writes (fn(x) -> x) under the hood and later the entire lambda function is executed .().