ksc

# Ksc

An Elixir implementation of the [Kaitai Struct](https://kaitai.io/) compiler and runtime. Ksc compiles `.ksy` format descriptions into Elixir modules that parse binary data into structured maps.

## Installation

Add `ksc` to your dependencies in `mix.exs`:

```elixir
def deps do
  [
    {:ksc, "~> 0.1.0"}
  ]
end
```

## Quick Start

Given a Kaitai Struct format definition (`hello_world.ksy`):

```yaml
meta:
  id: hello_world
seq:
  - id: one
    type: u1
```

Compile it to an Elixir source file:

```sh
mix ksc.compile hello_world.ksy --output lib/formats
```

This writes `lib/formats/hello_world.ex` containing a `Ksc.Compiled.HelloWorld` module. You can also point it at a directory to compile all `.ksy` files at once:

```sh
mix ksc.compile my_formats/ --output lib/formats
```

Use `--namespace` to set a custom module prefix (default: `Ksc.Compiled`):

```sh
mix ksc.compile my_formats/ --output lib/formats --namespace MyApp.Formats
```

Then use the generated module to parse binary data:

```elixir
result = Ksc.Compiled.HelloWorld.from_file("data.bin")
result.one
#=> 80

result = Ksc.Compiled.HelloWorld.from_binary(<<42>>)
result.one
#=> 42
```

## Example: Parsing with Enums

```yaml
# enum_0.ksy
meta:
  id: enum_0
  endian: le
seq:
  - id: pet_1
    type: u4
    enum: animal
  - id: pet_2
    type: u4
    enum: animal
enums:
  animal:
    4: dog
    7: cat
    12: chicken
```

```elixir
{:ok, mod} = Ksc.compile_and_load("enum_0.ksy")
result = mod.from_binary(<<7, 0, 0, 0, 12, 0, 0, 0>>)
result.pet_1  #=> :cat
result.pet_2  #=> :chicken
```

## Running Tests

Ksc uses the official [Kaitai Struct test suite](https://github.com/kaitai-io/kaitai_struct_tests) for validation.

```sh
mix deps.get
mix test
```