EventCore Macros

Procedural macros for the EventCore event sourcing library.

Overview

This crate provides derive macros and attribute macros to reduce boilerplate when implementing commands and other EventCore patterns.

Features

#[derive(Command)]

The Command derive macro helps implement the EventCore Command trait by:

• Generating a type-safe StreamSet phantom type
• Implementing the read_streams method based on #[stream] field attributes
• Providing clear guidance on what methods still need manual implementation

Example

use eventcore_macros::Command;
use eventcore::types::StreamId;

#[derive(Command)]
struct TransferMoney {
    #[stream]
    from_account: StreamId,
    #[stream]
    to_account: StreamId,
    amount: Money,
}

// The macro generates:
// - TransferMoneyStreamSet phantom type
// - Implementation of read_streams() that returns [from_account, to_account]
//
// You still need to implement:
// - type Input = YourInputType
// - type State = YourStateType  
// - type Event = YourEventType
// - fn apply()
// - async fn handle()

Future Macros

Additional macros are planned for future releases:

• command! declarative macro for simpler command definitions
• #[stream] attribute enhancements
• Helper macros for common patterns

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.