What's New in Elixir #1 (April 6, 2012)

[Alexei Sholik]

Last week Elixir has seen a lot of new features, improvements, and bug fixes. In this little post I'm going to highlight some of the most prominent ones.

* Access protocol has been added for tuples, lists, strings, and whatnot. It allows us to easily access elements of a collection. We can also use a regex to find the first match in a string or a list. Examples follow:

    dict = [a: 1, b: 2, c: 3]

    dict[:a]   #=> 1

    dict[:d]   #=> nil

    tuple = {5, 4, 3, 2, 1}

    tuple[1]   #=> 5

    tuple[0]   #=> nil

    tuple[-1]  #=> 1

    defrecord TestRec, red: 0, green: 0, blue: 0

    r = TestRec[red: 255, blue: 80]  #=> new record

    s = "The quick brown fox jumps over the lazy dog."

    s[%r/[a-z]+o[a-z]+/]  #=> "brown"

* Access protocol also makes it possible to pattern-match records:

    defrecord TestRec, red: 0, green: 0, blue: 0

    r = TestRec[red: 255, blue: 80]  #=> new record

    case r do

    match: TestRec[red: 0]

      :no_match

    match: TestRec[red: red, blue: 80]

      :ok

    end

    #=> :ok

    red === 255  #=> true

* The `Orddict` module is no longer with us, it has been renamed to `Keyword`. The new module only allows atoms to be used as keys. A general purpose module for dicts will be added sooner or later.

* The `Enum`[1] module has been cleaned up a bit and got new functions, namely `drop_while`, `take_while`, and `split_with`.

  [1]: https://github.com/elixir-lang/elixir/blob/6f5611317a3d3102f60dbb319f88f2ca1d561c11/lib/enum.ex

* The `List`[2] module has also seen some improvements. It now supports access protocol, the `append` function was renamed to `concat`, and a new `range` function has been implemented.

  [2]: https://github.com/elixir-lang/elixir/blob/28eaff894e527643ba58b85fb975b5963679542b/lib/list.ex

* Support for nested modules has been added.

    defmodule Father do

      defmodule Child do

        def child_fun(str) do

          IO.puts str

        end

      end

      def fun do

        Child.child_fun "some argument"

      end

    end

    Father.Child.child_fun "hello!"

* The `Regex` module has received new functions, namely, `source` and `opts`. It can also be `inspect`ed now.

    reg = %r/[a-z]+o[a-z]+/im

    Regex.source reg  #=> "[a-z]+o[a-z]+"

    Regex.opts reg    #=> "im"

    inspect reg       #=> "%r\"[a-z]+o[a-z]+\"im"

* A new `read_info` function has been added to the File module allowing users to query for file attributes.

  [3]: https://github.com/elixir-lang/elixir/blob/35b22c598defd8be07d46d2e7e8fc0ddf9ec4e80/lib/file.ex

---

That's it for this week. I think it's been a great one! If anyone of you has something in the works in a separate fork or branch, please let me know so that I can highlight your contributions too.

Thank you all and see you next week.

--
Best regards
Alexei Sholik

[Ngoc]

Nice syntax.

I'm new to Elixir.
I know Erlang and Scala, but for more than a year now I've been
playing almost only with Scala. I'm looking for a chance to work more
with Erlang, and Elixir provides a lot of motivation!

Why CHANGELOG is empty?
https://github.com/elixir-lang/elixir/blob/master/CHANGELOG.md

I see there's a lot of doc in the source code
But why there's no reference manual at the home page?

>   [1]:https://github.com/elixir-lang/elixir/blob/6f5611317a3d3102f60dbb319f...

>
> * The `List`[2] module has also seen some improvements. It now supports
> access protocol, the `append` function was renamed to `concat`, and a new
> `range` function has been implemented.
>

>   [2]:https://github.com/elixir-lang/elixir/blob/28eaff894e527643ba58b85fb9...

>
> * Support for nested modules has been added.
>
>     defmodule Father do
>       defmodule Child do
>         def child_fun(str) do
>           IO.puts str
>         end
>       end
>
>       def fun do
>         Child.child_fun "some argument"
>       end
>     end
>
>     Father.Child.child_fun "hello!"
>
> * The `Regex` module has received new functions, namely, `source` and
> `opts`. It can also be `inspect`ed now.
>
>     reg = %r/[a-z]+o[a-z]+/im
>     Regex.source reg  #=> "[a-z]+o[a-z]+"
>     Regex.opts reg    #=> "im"
>     inspect reg       #=> "%r\"[a-z]+o[a-z]+\"im"
>
> * A new `read_info` function has been added to the File module allowing
> users to query for file attributes.
>

>   [3]:https://github.com/elixir-lang/elixir/blob/35b22c598defd8be07d46d2e7e...

[José Valim]

Why CHANGELOG is empty? 

https://github.com/elixir-lang/elixir/blob/master/CHANGELOG.md

There wasn't an official release yet, so there isn't a CHANGELOG.

Once we get to release v0.9.0, I will start maintaining the changelog regularly. 

I see there's a lot of doc in the source code
But why there's no reference manual at the home page?

Because we are still working on a tool for it. http://github.com/elixir-lang/exdoc :)

The weblog should come soon as well. :)