Ok Jose
A tiny library to pipe functions that
return {:ok, _} or {:error, _} without
having you to mess with matching everywhere.
Motivation
A lot of erlang libraries follow the
convention of returning {:ok, _} and
{:error, _} tuples to denote success/failure.
I just wanted an easy way to pipe
functions in a happy path, that is, a
pipe that expects {:ok, _} to be returned
at each point. If an non-ok thing is
found at any point it breaks the rest of
the chain execution and it's returned
as result.
So, for example, the following code
filename
|> File.read()
|> case do
{:ok, content} ->
content |> Poison.Parser.parse()
{:error, _} = error -> error
end
can be written as:
filename |> File.read |> Poison.Parser.parse |> ok
or alternatively:
ok(filename |> File.read |> Poison.Parser.parse)
Usage
Just import OkJose, it will provide an
ok/1 macro that you can pipe to.
Example
def dup(x), do: {:ok, x * 2}
def nop(x), do: {:error, x}
12 |> dup |> dup |> ok # => {:ok, 48}
24 |> nop |> dup |> ok # => {:error, 24}
24 |> dup |> ok! # => 48
24 |> nop |> dup |> ok! # raises
Installation
- Add ok to your list of dependencies in
mix.exs:
def deps do
[{:ok_jose, "~> 0.0.1"}]
end
About ok
I wanted name this library ok, but the hex
package name was already taken. So I just wanted to make a
tribute to @josevalim.
Actually both projects are trying to solve the
same issue. But I think this one has an easier
syntax that consist of just piping to ok