objc2-encode

Objective-C type-encoding in Rust.

This crates provides types to parse and compare Objective-C type-encodings created with the @encode directive.

See the docs for a more thorough overview.

This crate is part of the objc2 project, see that for related crates.

lib.rs:

Objective-C type-encoding

The Objective-C directive @encode encodes types as strings, and this is used in various places in the runtime.

This crate provides the Encoding type to describe and compare these type-encodings, and the EncodingBox type which does the same, except it can be parsed from an encoding at runtime.

The types from this crate is exported under the objc2 crate as objc2::encode, so usually you would use it from there.

Example

Parse an encoding from a string and compare it to a known encoding.

use objc2_encode::{Encoding, EncodingBox};
let s = "{s=i}";
let enc = Encoding::Struct("s", &[Encoding::Int]);
let parsed: EncodingBox = s.parse()?;
assert!(enc.equivalent_to_box(&parsed));
assert_eq!(enc.to_string(), s);

Further resources

• Objective-C, Encoding and You.
• Apple's documentation on Type Encodings.
• How are the digits in ObjC method type encoding calculated?
• clang's source code for generating @encode.