# Common Crate

## Overview

The `common` crate provides a foundational set of shared types and utilities essential for building high-frequency trading applications within the Foxhunt ecosystem. It encapsulates core data structures, error handling patterns, and common helpers used across various components.

## Features

*   **Market Data & Order Types:** Defines standardized structs for market data (e.g., `Tick`, `OrderBook`) and various order types (e.g., `LimitOrder`, `MarketOrder`).
*   **High-Precision Time Utilities:** Offers utilities for working with nanosecond-resolution timestamps and duration calculations critical for HFT.
*   **Robust Error Handling:** Implements a custom `FoxhuntError` enum and `Result` type for consistent and traceable error management across the system.
*   **Data Validation Helpers:** Provides functions for validating common HFT parameters such as prices, quantities, and instrument IDs.
*   **Serialization/Deserialization:** Includes helpers and derive macros for efficient data serialization (e.g., using `serde`) for inter-process communication or persistence.
*   **Instrument & Asset Definitions:** Standardized types for defining trading instruments, assets, and exchanges.

## Usage

```rust
use common::types::{Order, OrderSide, Price, Quantity, InstrumentId};
use common::errors::FoxhuntError;

fn create_limit_order(instrument: InstrumentId, price: Price, quantity: Quantity) -> Result<Order, FoxhuntError> {
    if price.value() <= 0.0 || quantity.value() <= 0.0 {
        return Err(FoxhuntError::ValidationError("Price and quantity must be positive".to_string()));
    }
    Ok(Order::new_limit(instrument, OrderSide::Buy, price, quantity))
}

let instrument = InstrumentId::new("BTCUSD".to_string());
let order = create_limit_order(instrument, Price::new(60000.0), Quantity::new(0.5));
println!("{:?}", order);
```

## Testing

```bash
cargo test --package common
```

## Documentation

Comprehensive API documentation is available at [docs.rs/common](https://docs.rs/common).