arc-lang

README

Systems Programming Language
High Performance, Native Code, Modern Syntax

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What is Arc?

Arc is a modern systems programming language for building native applications, servers, CLI tools, AI model inference, and kernel drivers with high performance.

Arc uses automatic reference counting for memory safety, provides zero-cost abstractions, and seamless C/C++ interoperability. The language compiles to efficient native code for x86-64, ARM64, and other CPU architectures.

Hardware acceleration built-in: When you need it, Arc functions can also compile to GPUs and TPUs without leaving your codebase or learning new APIs.

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Language Overview

AI Model Integration

import "ai"
import "io"

func main() {
    // Load model from file
    let model = ai.load_model("models/model-7b.gguf")
    defer model.free()
    
    // Configure inference
    let config = ai.InferenceConfig{
        temperature: 0.7,
        top_p: 0.9,
        max_tokens: 512
    }
    
    // Run inference
    let prompt = "Explain quantum computing in simple terms:"
    let tokens = model.tokenize(prompt)
    
    for token in model.generate(tokens, config) {
        let text = model.decode(token)
        io.printf("%s", text)
    }
}

Type System

// Fixed-width integers
let i: int32 = -500
let u: uint64 = 10000

// Pointer-sized integers
let size: usize = 100      // Unsigned (array indexing, sizes)
let offset: isize = -4     // Signed (offsets)

// Floating point
let f: float32 = 3.14
let d: float64 = 2.71828

// Slices (view into memory, ptr + length, no allocation)
let view: []byte = buffer[0..64]

// Mutable references — &mut in type, & at call site
func increment(x: &mut int32) { x += 1 }
increment(&i)

// Interfaces (value types — stack allocated with let)
interface Point {
    x: int32
    y: int32
}

// Interfaces (reference types — heap allocated with var)
interface Client {
    name: string
    port: int32
}

Memory Management

Arc uses automatic reference counting for var declarations and manual allocation for low-level work:

// Manual heap allocation
let buf = new [4096]byte
mem_zero(buf, sizeof(buf))
defer delete(buf)

// Heap allocation (via FFI)
extern c {
    func malloc(usize) *void
    func free(*void) void
}

let ptr = malloc(1024)
defer free(ptr)  // Cleanup on scope exit

// Get address of variable for extern calls
let val = 42
let raw = memptr(&val)    // address of val as memory pointer
let sentinel = memptr(-1) // cast integer value to memory pointer

Foreign Function Interface

Direct interop with C and C++:

// C libraries
extern c {
    func printf(*byte, ...) int32
    func sqlite3_open(*byte, **sqlite3) int32
}

// C++ libraries
extern cpp {
    namespace DirectX {
        class ID3D11Device {
            virtual func CreateBuffer(
                self *ID3D11Device,
                *D3D11_BUFFER_DESC,
                **ID3D11Buffer
            ) HRESULT
        }
    }
}

Async/Await

async func fetch_data(url: string) string {
    let response = await http.get(url)
    return response.body
}

async func main() {
    let data = await fetch_data("[https://api.example.com](https://api.example.com)")
    io.print(data)
}

Generics

Monomorphized at compile time. Note the use of square brackets [...] for type parameters.

func swap[T](a: &mut T, b: &mut T) {
    let tmp: T = a
    a = b
    b = tmp
}

let x = 10
let y = 20
swap(&x, &y)

interface Box[T] {
    value: T
}

func get[T](self b: Box[T]) T {
    return b.value
}

---

Example Programs

HTTP Server

namespace main

import "net"
import "io"

async func handle_request(conn: net.TcpStream) {
    let buffer: vector[byte] = {1, 2, 3}
    let bytes_read = await conn.read(&buffer)
    
    let response = "HTTP/1.1 200 OK\r\nContent-Length: 2\r\n\r\nOK"
    await conn.write(response.as_bytes())
}

async func main() {
    let listener = net.TcpListener.bind("0.0.0.0:8080")
    io.print("Server listening on port 8080")
    
    for {
        let (conn, addr) = await listener.accept()
        // Fire-and-forget concurrent processing
        process func(c: net.TcpStream) {
             handle_request(c)
        }(conn)
    }
}

Database Application

namespace main

extern c {
    interface sqlite3 {}
    interface sqlite3_stmt {}
    
    const SQLITE_OK: int32 = 0
    const SQLITE_ROW: int32 = 100
    
    func sqlite3_open(*byte, **sqlite3) int32
    func sqlite3_close(*sqlite3) int32
    func sqlite3_prepare_v2(*sqlite3, *byte, int32, **sqlite3_stmt, **byte) int32
    func sqlite3_step(*sqlite3_stmt) int32
    func sqlite3_column_text(*sqlite3_stmt, int32) *byte
    func printf(*byte, ...) int32
}

func main() {
    var db: sqlite3 = null
    
    if sqlite3_open("app.db", memptr(&db)) != SQLITE_OK {
        printf("Failed to open database\n")
        return
    }
    defer sqlite3_close(db)
    
    var stmt: sqlite3_stmt = null
    sqlite3_prepare_v2(db, "SELECT name FROM users", -1, memptr(&stmt), null)
    
    for sqlite3_step(stmt) == SQLITE_ROW {
        let name = sqlite3_column_text(stmt, 0)
        printf("User: %s\n", name)
    }
}

Graphics Application (DirectX 11)

namespace main

type HRESULT = int32
const D3D11_SDK_VERSION: uint32 = 7
const D3D_DRIVER_TYPE_HARDWARE: uint32 = 1

extern cpp {
    namespace DirectX {
        func D3D11CreateDevice(
            *void, uint32, *void, uint32, *uint32, uint32,
            uint32, **ID3D11Device, *uint32, **ID3D11DeviceContext
        ) HRESULT

        class ID3D11Device {
            virtual func Release(self *ID3D11Device) uint32
        }
        
        class ID3D11DeviceContext {
            virtual func Release(self *ID3D11DeviceContext) uint32
        }
    }
}

func main() {
    var device:  DirectX.ID3D11Device        = null
    var context: DirectX.ID3D11DeviceContext = null

    // Direct C++ Interop
    let hr = DirectX.D3D11CreateDevice(
        null, D3D_DRIVER_TYPE_HARDWARE, null, 0, null, 0,
        D3D11_SDK_VERSION, memptr(&device), null, memptr(&context)
    )

    if hr != 0 {
        return
    }
    defer device.Release()
    defer context.Release()
    
    // Use device...
}

Kernel Module

namespace driver

import "linux/kernel/driver"
import "linux/kernel/log"

func init_module() int32 {
    log.info("Driver loading")
    
    let dev = driver.CharDevice.new("custom_device", 0)
    
    dev.on_read(func(file: driver.File, buffer: []byte, size: uint64) int64 {
        let data = "Hello from kernel"
        mem_copy(memptr(&buffer[0]), data.as_bytes(), data.len())
        return int64(data.len())
    })
    
    return 0
}

func cleanup_module() {
    log.info("Driver unloading")
}

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Hardware Acceleration

Arc can compile functions to run on specialized hardware when you need maximum performance. The target (cuda, metal, rocm, etc.) is set in build.arc, not in source code.

namespace compute

import "ai"

// CPU version (default)
func process_data(data: []float32, size: usize) {
    for let i: usize = 0; i < size; i++ {
        data[i] = data[i] * 2.0
    }
}

// GPU version — target set in build.arc
gpu func process_gpu(data: []float32, size: usize) {
    // Note: thread_id() is an intrinsic valid only inside gpu func
    let idx = thread_id()
    if idx < size {
        data[idx] = data[idx] * 2.0
    }
}

// TPU version
gpu func process_tpu(data: Tensor) Tensor {
    return data.multiply(2.0)
}

// Train model on GPU
gpu func train(model: &mut ai.Model, data: Tensor) {
    for epoch in 0..100 {
        let loss = model.forward(data)
        model.backward(loss)
        model.step()
    }
}

func main() {
    let model = ai.load_model("models/model-13b.gguf")
    let data = ai.load_tensor("training_data.bin")
    
    await train(&model, data)
    
    io.printf("Training complete\n")
}

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Package Management

Arc downloads packages via HTTPS to a local cache (~/.arc/). No system package managers required.

Source Code

// main.ax
namespace main

import c "sqlite3"
import c "curl"
import "io"
import "ai"

func main() {
    // Use imported libraries
}

The compiler detects your platform and downloads the appropriate packages to ~/.arc/cache/.

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Supported Targets

CPU Architectures

• x86-64 (Intel, AMD)
• ARM64 (Apple Silicon, ARM servers)
• RISC-V (in progress)

Operating Systems

• Linux (Ubuntu, Debian, Arch, Fedora, Alpine, etc.)
• macOS (Intel and Apple Silicon)
• Windows (x64)
• FreeBSD

Accelerators

• NVIDIA GPUs (gpu.cuda)
• AMD GPUs (gpu.rocm)
• Apple Silicon (gpu.metal)
• Intel GPUs (gpu.oneapi)
• Google TPUs (tpu)
• AWS Trainium (aws.trainium)

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Installation

git clone [https://github.com/arc-language/arc-lang](https://github.com/arc-language/arc-lang)
cd arc-lang/cmd
./build build
./test_runner

Build a Program

./arc build main.ax -o main
./main

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Documentation

• Language Reference - Complete syntax and semantics
• Grammar Specification - Language grammar
• Package Management - Dependency resolution
• Foreign Function Interface - C/C++ interop
• Kernel Drivers - Systems programming
• Compiler Intrinsics - Built-in functions

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Current Status

Beta Release

Working:

• Core language features
• C/C++ FFI
• Package management
• CPU compilation (x86-64, ARM64)
• GPU compilation (CUDA, Metal)
• Kernel driver support

In Development:

• Standard library
• AI model runtime
• TPU backend
• Additional GPU targets
• Tooling (LSP, debugger)

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License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.