SYX vs Swift
Short answer: SYX is not Swift. It borrows a Swift-like surface (func, let / var, protocols, generics, async / await) so the language feels familiar, but it is an independent language with its own semantics, standard library, and a Rust-implemented toolchain.
| Swift | SYX | |
|---|---|---|
| Who defines it | Apple / Swift.org | SYX Language Project |
| Compiler | Swift compiler (C++/Swift) | Rust workspace (syx-* crates) |
| Source extension | .swift | .sy |
| Project file | Package.swift (SPM) | syx.toml |
| Primary runtimes | Swift runtime / Darwin & more | Stack VM, LLVM native AOT, Wasm |
| Relationship | — | Inspired by Swift syntax; not a dialect |
Where behaviour commonly diverges
Names often match while meaning differs — especially:
String/ character indexing and Unicode handling- Memory model and ownership expectations
- Macros and result-builder style features
- Concurrency and cross-module actors
For a chapter-level tour of differences, start with the Language Guide preface. For “does SYX support X today?”, use Capabilities.