https://github.com/oltarasenko/epipe

Brings Elixir's pipe (|>) and with to Erlang world
https://github.com/oltarasenko/epipe

erlang

Last synced: 17 days ago
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Brings Elixir's pipe (|>) and with to Erlang world

• Host: GitHub
• URL: https://github.com/oltarasenko/epipe
• Owner: oltarasenko
• License: apache-2.0
• Created: 2018-05-02T22:02:16.000Z (over 6 years ago)
• Default Branch: master
• Last Pushed: 2018-09-17T08:47:14.000Z (about 6 years ago)
• Last Synced: 2024-10-19T07:31:52.967Z (26 days ago)
• Topics: erlang
• Language: Erlang
• Homepage:
• Size: 10.7 KB
• Stars: 37
• Watchers: 2
• Forks: 4
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
epipe 

=====

[![Build Status](https://travis-ci.org/oltarasenko/epipe.svg?branch=master)](https://travis-ci.org/oltarasenko/epipe)

[![Hex pm](http://img.shields.io/hexpm/v/epipe.svg?style=flat)](https://hex.pm/packages/epipe) [![hex.pm downloads](https://img.shields.io/hexpm/dt/epipe.svg?style=flat)](https://hex.pm/packages/epipe)

Erlang pipes

Influenced by Elixir pipe (|>) and with operators. Brings similar functionality to erlang

Intro

-----

Probably you've seen code like this:

``` erlang

case gen_tcp:connect(Host, Port, Otps) of

    {ok, Socket} -> 

        case do_handshake(Socket) of

            ok -> send_message(Socket);

            {error, Reason} -> exit(normal)

        end;

    {error, Reason} -> exit(normal)

end

```

Sometimes the amount of the nested cases goes even deeper.... Which makes the code quite

complex for understanding and debugging.

Epipe allows to rewrite it in a very flat way:

``` erlang

connect({Host, Port, Opts}) -> 

    case gen_tcp:connect(Host, Port, Otps) of

        {ok, Socket} -> {ok, Socket};

        {error, Reason} -> {error, Reason}

    end.

handshake(Socket) -> 

    case do_handshake(Socket) of

        ok -> {ok, Socket};

        {error, Reason} -> {error, Reason}

    end.

send_message(Socket) ->

    case do_send_message(Socket) of

        response -> {ok, response};

        Error -> {error, Error}

    end.

FunctionsList = [

    {connect_fun, fun connect/1}, 

    {handshake_fun, fun handshake/1}, 

    {send_message_fun, fun send_message/1}

],

epipe:run(FunctionsList, {Host, Port, Opts}).

```

Which allows to 'pipe' the initial data through FunctionsList, stopping on any step

which would produce {error, ...} value.

Examples

--------------

```

sample1() -> 

    Fun1 = fun(Val) -> {ok, Val + 1} end,

    Fun2 = fun(Val) -> {ok, Val + 2} end,

    epipe:run([{add_one, Fun1}, {add_two, Fun2}], 0).

```

Would produce {ok, 3}

```

sample2() -> 

    Fun1 = fun(Val) -> {ok, Val + 1} end,

    Fun2 = fun(Val) -> {error, "Can't process data"} end,

    epipe:run([{step1, Fun1}, {step2, Fun2}, {step3, Fun1}], 0).

```

Would produce {error, step2, "Can't process data", 1}, giving not only error reason,

but also would give a hint, about the failing step. 

Build

-----

    $ rebar3 compile