Awesome

nscheme readme

A fast, stack-based, JIT-compiling, concurrency-friendly scheme interpreter. Currently a work in progress, it doesn't do much yet.

To build, type make, and that's it for now. A ./configure script and testing framework will be coming soon.

TODO

• parser
  • basic lexer+parser
  • global symbol table
    • add locking once multithreading is implemented
  • handle basic types (ints, characters, null, ...)
  • handle unicode
    • generic utf* handling or just utf8?
  • handle quoted forms
  • handle dotted form pairs, (a . b)
  • handle vectors
  • handle strings
  • handle bytevectors
  • properly handle parser errors
• I/O
  • [/] write primitives
    • display
    • write
  • read primitive
  • implement port handles
    • implement a generic port structure to handle I/O for many different sources eg. sockets, files, memory buffers
    • handle port argument for I/O primitives display, write, read, ...
    • Implement open/close procedures for different sources
• virtual machine
  • basic stack-based structure for vm
  • tree walker interpreter
    • some basic forms (lambda, if, define, top-level begin)
    • expression-like begin
    • tail recursion (note: may not be needed if all lambdas are JIT'd on first call)
    • ! syntax expansion
  • JIT compiler
    • Tail recursion
    • Scope analysis pass
      • handle local (define ...) forms
        • single local variable definitions
        • function definition form
      • handle expression-like begin forms that generate new scope
    • ! handle nested lambdas
    • ! syntax expansion
    • optimizations
      • common subexpression elimination
      • dead code elimination
      • optimizing code which is guaranteed to have no side effects
      • inline small functions
        • will be especially useful for syntax extensions which generate lambdas, eg. named lets)
  • garbage collection
    • ! implement basic pointer bumping allocation
    • ! implement mark-and-compact collector
    • figure out a way to make it work with multiple threads (arenas?)
  • exception handling
    • implement exception stack in vm struct
    • add with-exception-handler and error primitives
  • module system
    • figure out what to put here
    • implement r7rs libraries and associated procedures
  • FFI
    • maybe look at how python does it, or lua or chicken or something
• command line interface
  • add help output
  • add file argument
  • allow specifying options like environment, modules, output location as arguments
• testing
  • I/O tests
    • for basic std{in,out}
    • for network sockets
    • for memory buffers
  • stress testing for compiler
  • unit tests for scheme procedures