cisp

April 4, 2026 ยท View on GitHub

CI

A compact Lisp interpreter written in C.

Features

  • Cross-platform: Runs on Linux, macOS, and Windows
  • Lightweight: Single binary with minimal dependencies
  • Lisp-2: Functions and variables have separate namespaces
  • Dynamic library support: Load shared libraries with the load function
  • Escape continuations: Supports call/cc
  • Tail call optimization: Efficient execution of recursive functions
  • Macro system: Full macro support with backquote syntax
  • Rich data types: Integers, floats, characters, strings, symbols, and cons cells
  • C plugin support: Write plugins in C for extending functionality

C Plugin Example

You can extend cisp with C plugins. See example/hello.c for an example:

int cisp_init(ENV *env) {
  add_sym(env, NODE_BUILTINFUNC, "hello", do_hello);
  return 0;
}

Compile with:

# Linux
gcc -fPIC -I. -shared -o lib/hello.so ./example/hello.c

# Windows
gcc -fPIC -I. -shared -o lib/hello.so ./example/hello.c libcisp.a

Build

$ make

License

Public Domain

Author

Yasuhiro Matsumoto (a.k.a. mattn)