Crate eqswift 

eq-swift — Zero-config Rust-to-Swift FFI

A thin, ergonomic wrapper around UniFFI that lets you write your entire foreign interface in Rust — no UDL files, no build.rs, no duplication.

Just annotate your items with #[eqswift::export] or #[derive(eqswift::Record)], call eqswift::setup!() once at the top of lib.rs, and build.

Quick Start

eqswift::setup!();

#[eqswift::export]
pub fn add(a: u32, b: u32) -> u32 {
    a + b
}

#[derive(eqswift::Record)]
pub struct Person {
    pub name: String,
    pub age: u32,
}

#[derive(eqswift::Object)]
pub struct Greeter;

#[eqswift::export]
impl Greeter {
    #[uniffi::constructor]
    pub fn new() -> Self {
        Self
    }

    pub fn greet(&self, name: String) -> String {
        format!("Hello, {name}!")
    }
}

Then build and generate Swift bindings:

cargo build
cargo eqswift swift --out-dir swift/Generated

Macros

Macro	Purpose
setup!	One-time initialization. Call once at the top of lib.rs.
export	Mark a free function or impl block for export. Constructors need #[uniffi::constructor].
Record	Derive for plain data structs (Swift struct).
Object	Derive for reference types with methods (Swift class).
Enum	Derive for enums.
Error	Derive for error enums.

Supported Types

Most Rust primitives map directly to Swift:

Rust	Swift
u32	UInt32
i32	Int32
f64	Double
bool	Bool
String	String
Vec<T>	[T]
Option<T>	T?
Result<T, E>	throws

See the UniFFI type docs for the complete list.

Macros

setup

One-time setup macro.

Structs

Greeter

An object exported to Swift as a class with methods.

Person

A simple data record exported to Swift as a struct.

Functions

add

version

Attribute Macros

export

Export a function, method, impl block, or trait to foreign languages.

Derive Macros

Enum

Error

Object

Record