# Zigler
Library test status:
Dependent package test status:
## Installation
Zigler is [available in Hex](https://hex.pm/zigler), and the package can be installed
by adding `zigler` to your list of dependencies in `mix.exs`:
```elixir
def deps do
[
{:zigler, "~> 0.3.0", runtime: false}
]
end
```
## Documentation
Docs can be found at [https://hexdocs.pm/zigler](https://hexdocs.pm/zigler).
## Currently supported platforms
- Linux
- FreeBSD (tested, but not subjected to CI)
- MacOS (I believe it works but is still offically untested)
## 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.
```elixir
defmodule ExampleZig do
use Zigler, otp_app: :my_app
~Z"""
/// nif: example_fun/2
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:
```elixir
defmodule ZigCollections do
use Zigler, otp_app: :my_app
~Z"""
/// nif: string_count/1
fn string_count(string: []u8) i64 {
return @intCast(i64, string.len);
}
/// nif: list_sum/1
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.
```elixir
defmodule Allocations do
use Zigler, otp_app: :my_app
~Z"""
/// nif: double_atom/1
fn double_atom(env: beam.env, string: []u8) beam.atom {
var double_string = beam.allocator.alloc(u8, string.len * 2) catch {
return beam.raise_enomem(env);
};
defer beam.allocator.free(double_string);
for (string) | char, i | {
double_string[i] = char;
double_string[i + string.len] = char;
}
return beam.make_atom(env, double_string);
}
"""
end
iex> Allocations.double_atom("foo")
:foofoo
```
It is a goal for Zigler to make using *it* to bind C libraries easier
than using C to bind C libraries. Here is an example:
```elixir
defmodule BlasDynamic do
use Zigler,
otp_app: :zigler,
libs: ["/usr/lib/x86_64-linux-gnu/blas/libblas.so"],
include: ["/usr/include/x86_64-linux-gnu"]
~Z"""
const blas = @cImport({
@cInclude("cblas.h");
});
/// nif: blas_axpy/3
fn blas_axpy(env: beam.env, a: f64, x: []f64, y: []f64) beam.term {
if (x.len != y.len) {
return beam.raise_function_clause_error(env);
}
blas.cblas_daxpy(@intCast(c_int, x.len), a, x.ptr, 1, y.ptr, 1);
return beam.make_f64_list(env, y) catch {
return beam.raise_function_clause_error(env);
};
}
"""
end
test "we can use dynamically-linked blas" do
# returns aX+Y
assert [11.0, 18.0] == BlasDynamic.blas_axpy(3.0, [2.0, 4.0], [5.0, 6.0])
end
```
Zigler even has support for zig docstrings.
```elixir
defmodule AllTheDocs do
use Zigler, otp_app: :zigler
~Z"""
/// a zero-arity function which returns 47.
/// nif: zero_arity/0
fn zeroarity() i64 {
return 47;
}
"""
end
iex> h AllTheDocs.zeroarity
def zeroarity()
a zero-arity function which returns 47.
```
## Zigler Principles
1. Make doing the right thing easy.
2. Use magic, but sparingly.
3. Let the user see behind the curtain.
4. Let the user dial in magic as they choose.
5. Magic shouldn't get in the way
