Ch4s3 / zigler

zig nif assistance

Zigler

Zig Nifs made easy

Wouldn't it be nice if you could make NIFs as easily as you can use the asm keyword in C?

This is now possible, using the magic of Zig.

defmodule ExampleZig do
  use Zigler, app: :my_app

  ~Z"""
  @nif("example_fun")
  fn example_fun(value1: f64, value2: f64) bool {
    return value1 > value2;
  }
  """

end

iex> ExampleZig.example_fun(0.1, 0.4)
false

iex> ExampleZig.example_fun(0.8, -0.8)
true

Zigler will do automatic type marshalling between Elixir code and Zig code. It will also convert trickier types into types you care about, for example:

defmodule ZigCollections do
  use Zigler, app: :my_app
  ~Z"""
  @nif("string_count")
  fn string_count(string: []u8) i64 {
    return @intCast(i64, string.len);
  }

  @nif("list_sum")
  fn list_sum(array: []f64) f64 {
    var sum: f64 = 0.0;
    for(array) | item | {
      sum += item;
    }
    return sum;
  }
  """
end

iex> ZigCollections.string_count("hello zig")
9
iex> ZigCollections.list_sum([1.0, 2.0, 3.0])
6.0

Memory allocation with zigler is easy! A standard BEAM allocator is provided for you, so any zig code you import will play nice with the BEAM.

defmodule Allocations do
  use Zigler, app: :my_app
  ~Z"""
  @nif("double_atom")
  fn double_atom(env: elixir.env, string: []u8) elixir.atom {
    var double_string = elixir.allocator.alloc(u8, string.len * 2)
      catch elixir.enomem(env);

    defer elixir.allocator.free(double_string);

    for (string) | char, i | {
      double_string[i] = char;
      double_string[i + string.len] = char;
    }

    return elixir.make_atom(env, double_string);
  }
  """
end

iex> Allocations.double_atom("foo")
:foofoo

Zigler even has support for zig docstrings.

defmodule AllTheDocs do
  use Zigler, app: :zigler
  ~Z"""
  /// a zero-arity function which returns 47.
  @nif("zeroarity")
  fn zeroarity() i64 {
    return 47;
  }
  """
end

iex> h AllTheDocs.zeroarity

                                def zeroarity()                                 

a zero-arity function which returns 47.

Installation

def deps do
  [
    {:zigler, git: "https://github.com/ityonemo/zigler.git"}
  ]
end

once you have this dependency, you should cache the zig build tools by running the following:

mix zigler.get_zig latest

Future installation

If available in Hex, the package can be installed by adding zigler to your list of dependencies in mix.exs:

def deps do
  [
    {:zigler, "~> 0.1.0"}
  ]
end

You'll also want to grab the latest zig binary and cache it with zigler. You can do this by executing:

Documentation can be generated with ExDoc and published on HexDocs. Once published, the docs can be found at https://hexdocs.pm/zigler.