Picrin is a lightweight R7RS scheme implementation written in pure C89. It contains a reasonably fast VM, an improved hygienic macro system, useful contribution libraries, and simple but powerful C interface.

• R7RS compatible
• Reentrant design (all VM states are stored in single global state object)
• Bytecode interpreter
• Direct threaded VM
• Internal representation by nan-boxing (available only on x64)
• Conservative call/cc implementation (VM stack and native c stack can interleave)
• Exact GC (simple mark and sweep, partially reference count)
• String representation by rope
• Hygienic macro transformers (syntactic closures, explicit and implicit renaming macros)
• Extended library syntax

See http://picrin.readthedocs.org/

Currently picrin is hosted on Github. You can freely send a bug report or pull-request, and fork the repository.

https://github.com/picrin-scheme/picrin

Just type make in the project root directory. You will find an executable binary newly created at bin/ directory.

$ make

When you are building picrin on x86_64 system, PIC_NAN_BOXING flag is automatically turned on (see include/picrin/config.h for detail).

make install target is provided. By default it installs picrin binary into /usr/local/bin/.

$ make install

Since picrin does not use autoconf, if you want to specify the install directory, pass the custom path to make via command line argument.

$ make install prefix=/path/to/dir

To build Picrin Scheme from source code, some external libraries are required:

• perl
• regex.h of POSIX.1
• libedit (optional)

Make command automatically turns on optional libraries if available. Picrin is mainly developed on Mac OS X and only tested on OS X or Ubuntu 14.04+. When you tried to run picrin on other platforms and found something was wrong with it, please send us an issue.

See AUTHORS