Having fun with Scheme

@raviqqe

Index

• Schemat: yet another Scheme formatter
• Implementing Scheme in Rust

Schemat

• Scheme code formatter
• Written in Rust unfortunately...
• Uses the same mfmt formatter library as Pen.
• Rust allocator API + bumpalo crate

Schemat

Some features are not supported yet.

• Range comments

  • #| This is a comment. |#

• Multi-line strings

  "foo \
    bar"
  

  • Read flags

Implementing Scheme in Rust

• VM is mostly done.
  • Written in Rust
  • The core logic is around 700 lines.
    • Mostly re-implementation of Ribbit
  • No-std and no-alloc
  • Can be used as a library.
  • Copy GC
• Bytecode compiler
  • Written in Scheme
  • Global variable get/set
• But write codes in Scheme as much as possible.

Next tasks...

• Scheme in Rust
  • More language features in the bytecode compiler
    • Closures
    • Slot variables
• Pen
  • sort and reverse functions
  • Syntax extension for list pattern matching
  • Compiler improvements

Summary

• Building a VM is fun (again.)