The include syntax in Stak Scheme

@raviqqe

August 17, 2025

Contents

• Stak Scheme
• Progress
  • The include syntax
  • Other R7RS compatibility improvements
• Future work

Stak Scheme

• A bytecode compiler and virtual machine (VM) for Scheme
  • The compiler is written in Scheme.
  • The VM is written in Rust.
• It aims to support the R7RS-small standard.
• Forked from Ribbit Scheme

References

• GitHub
• Website

Progress

• (Almost) full R7RS-small compatibility
  • The include syntax
• The website improvements

The (almost) full R7RS-small compatibility

• Stak Scheme is (almost) fully compatible with R7RS-small.
  • Other than the include and include-ci syntaxes...
  • Stak Scheme does not implement the full numeric tower either.

The include syntax

• The include syntax embeds S-expressions read from a specified path into source code at the location.
  • The include-ci syntax is its case-insensitive variant.
• Its argument must be a string literal.
• The include syntax is in the (scheme base) library.

(include "./foo.scm") ; -> (write-string "Hello, world!")

The current implementation in Stak Scheme

• The include syntax is the top-level "meta" syntax.
  • Similar to define-library and import library syntaxes.
• It is not part of the (scheme base) library.
• The syntax is processed by the compiler completely statically.
  • You cannot even call it with any arguments of the other macros whose denotations are string literals.

Other compatibility improvements

• define-syntax syntax in define-syntax syntax
• The write, write-simple, and write-shared procedures
• Partial implementation of SRFI 1

Other progress

• Rewriting Aruba in Go.
  • https://github.com/raviqqe/aruba-go
• Monza editor, the textarea element with syntax highlight
• Using a proper terminal library in REPL on the website

Future work

• Unicode support in the (scheme char) library
• close primitive optimization
• Closure space safety
• Stack trace

Summary

• Building Scheme is fun!