CapturePipe v0.1.0 CapturePipe View Source

To use this operator in one of your modules, you need to add the following to it:

use CapturePipe

This does the same thing as explicitly writing:

import Capturepipe
import Kernel, except: [|>: 2]

Link to this section Summary

Functions

Extended pipe-operator that allows the usage of bare function captures.

Link to this section Functions

Extended pipe-operator that allows the usage of bare function captures.

This is useful to insert the pipe's results into a datastructure such as a tuple.

What this macro does, is if it encounters a & capture, it wraps the whole operand in (...).() which is the anonymous-function-call syntax that Elixir's normal pipe accepts, that (argubably) is less easy on the eyes.

For instance, 10 |> &{:ok, &1} is turned into 10 |> (&{:ok, &1}).()

Examples

Still works as normal:

iex> [1,2,3] |> Enum.map(fn x -> x + 1 end)
[2,3,4]

Insert the result of an operation into a tuple

iex> 42 |> &{:ok, &1}
{:ok, 42}

It also works multiple times in a row.

iex> 20 |> &{:ok, &1} |> &[&1, 2, 3]
[{:ok, 20}, 2, 3]

Besides the function-capture syntax CapturePipe also enables you to use anonymnous functions directly inside a pipe, performing similar wrapping:

iex> 42 |> fn val -> to_string(val) end
"42"

Even if the pipes are nested deeply and interspersed with 'normal' pipe calls:

iex> (10
iex> |> &Kernel.div(20, &1)
iex> |> Kernel.-()
iex> |> to_string()
iex> |> &"The answer is: #{&1}!"
iex> |> String.upcase()
iex> |> &{:ok, &1}
iex> )
{:ok, "THE ANSWER IS: -2!"}

Currently, the implementation raises errors when captures or anonymous functions with a bad arity are used at runtime. This might be improved in the future to raise compile-time errors whenever possible instead.