Introduction
============

Picrin is a lightweight scheme implementation intended to comply with full R7RS specification. Its code is written in pure C99 and does not requires any special external libraries installed on the platform.

- R7RS compatibility (but partial support)
- reentrant design (all VM states are stored in single global state object)
- bytecode interpreter (based on stack VM)
- direct threaded VM
- internal representation by nan-boxing
- conservative call/cc implementation (users can freely interleave native stack with VM stack)
- exact GC (simple mark and sweep, partially reference count is used as well)
- string representation by rope data structure
- support full set hygienic macro transformers, including implicit renaming macros
- extended library syntax
- advanced REPL support (multi-line input, etc)
- tiny & portable library (all functions will be in `libpicrin.so`)

Installation
------------

- make `Makefile`

Change directory to `build` then run `cmake` to create Makefile. Once `Makefile` is generated you can run `make` command to build picrin::

  $ cd build

  $ cmake ..

Actually you don't necessarily need to move to `build` directory before running `cmake` (in that case `$ cmake .`), but I strongly recommend to follow above instruction.

- build

A built executable binary will be under bin/ directory and shared libraries under lib/::

  $ make

If you are building picrin on other systems than x86_64, PIC_NAN_BOXING flag is automatically turned on (see include/picrin/config.h for detail).

- install

Just running `make install`, picrin library, headers, and runtime binary are install on your system, by default into `/usr/local` directory. You can change this value via ccmake::

  $ make install

- run

Before installing picrin, you can try picrin without breaking any of your system. Simply directly run the binary `bin/picrin` from terminal, or you can use `make` to execute it like this::

  $ make run

- debug run

If you execute `cmake` with debug flag `-DCMAKE_BUILD_TYPE=Debug`, it builds the binary with all debug flags enabled (PIC_GC_STRESS, VM_DEBUG, DEBUG)::

  $ cmake -DCMAKE_BUILD_TYPE=Debug ..


Requirement
-----------

Picrin scheme depends on some external libraries to build the binary:

- perl
- lex (preferably, flex)
- getopt
- readline (optional)
- regex.h of POSIX.1 (optional)

Optional libraries are, if cmake detected them, automatically enabled.
The compilation is tested only on Mac OSX and Ubuntu. I think (or hope) it'll be ok to compile and run on other operating systems such as Arch or Windows, but I don't guarantee :(

Homepage
--------

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

https://github.com/wasabiz/picrin

IRC
---

There is a chat room on chat.freenode.org, channel #picrin.

LICENSE
-------

Copyright (c) 2013-2014 Yuichi Nishiwaki and other picrin contributors

Permission is hereby granted, free of charge, to any person obtaining a copy of
this software and associated documentation files (the "Software"), to deal in
the Software without restriction, including without limitation the rights to
use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
the Software, and to permit persons to whom the Software is furnished to do so,
subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.