Snail-Core

Snail-Core is a typed, pure-by-default functional language with Scheme syntax. It compiles to WasmGC. Scheme does not compile directly: its macros and libraries expand it into Snail-Core, and checking, specialization and code generation all happen there, so Scheme ships as libraries over the typed language. The compiler is a Snail-Core program and compiles itself. Erasing Snail-Core’s typed forms leaves an R7RS program with the same behavior, which is how stage 0 runs that source; Bootstrap explains it.

The chapters describe implemented behavior and mark proposed toolchain changes:

• Terms: programs, libraries, language forms and toolchain names.
• Types: scalars, data, typeclasses, effects and dynamic values.
• Macros and Scheme libraries: hygienic macros, generated libraries and Scheme on Snail-Core.
• Bootstrap and self-hosting: the erasure property, the two hosts and the stages that make the compiler compile itself.
• Libraries: the standard library and wire types.
• Projects and targets: inert descriptions, output directories and embedded artifact bundles.
• Compiler architecture: the passes, bootstrap, linking and incremental compilation.
• Application model: interactive applications in the browser.
• Development toolchain: building one library at a time, hot reload, the native project editor and the proposed application workflow.
• Proposed typed state: durable records and disposable cached views; an API for review, not implemented functionality.
• Notable omissions: what was left out, and why.
• References: influences and further reading.