# Picrin [![Build Status](https://travis-ci.org/wasabiz/picrin.png)](https://travis-ci.org/wasabiz/picrin)

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.

## Features

- 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`)

## Documentation

See http://picrin.readthedocs.org/

## 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. IRC logs here: https://botbot.me/freenode/picrin/

## How to use it

To build picrin, you need some build tools installed on your platform.

- cmake (>= 2.8)
- git

Because of submodule dependencies, it is necessary to get picrin's source code via git clone command. Basically our git dependencies are only due to submodules, so in fact, If you have no git on your machine, it is possible to build it by downloading a tarball from github page as well. But in such case, you are assumed to modify CMakeLists.txt by yourself to get it work completely. We just strongly recommend you to use git-clone.

### Generate `Makefile`

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

		$ cd build
        $ ccmake ..

	Actually you don't necessarily need to move to `build` directory before running `ccmake` (in that case `$ ccmake .`), 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
- libedit (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 :(

## Authors

See `AUTHORS`