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====================================================================== Contents

1. Introduction

2. Installation

3. Building from Source

4. Making a Contribution

======================================================================

1. Introduction ======================================================================

Whiley is a programming language particularly suited to safety-critical systems. It is a hybrid object-oriented and functional programming language which employs extended static checking to eliminate errors at compile time, including divide-by-zero, array out-of-bounds and null dereference errors.

Whiley compiles to the Java Virtual Machine and is fully inter-operable with existing Java applications. Whiley will operate on any system that can run Java including Windows, Mac OS and Linux. Whiley is released under the New BSD License --- see the LICENSE file for more on this.

To find out more, visit http://whiley.org

====================================================================== 2. Installation

There are several ways to get started with Whiley:

1. You can run it directly in your web browser.

2. Or, you can download and setup the Whiley Development Kit.

The Eclipse plugin is the easiest way to get started with Whiley (see instructions below). If you don't use Eclipse, another simple option is to download and run the executable Jar. Finally, developers may like to download the Whiley Development Kit (WDK), which includes the source code for the compiler/runtime and various scripts to simplify compiling and running Whiley programs from the command-line.

2.1 Whiley Labs

To run Whiley in your web-browser, goto http://whileylabs.com

2.2 Whiley Development Kit (WDK)

To install the Whiley Development Kit, first download it from http://whiley.org/downloads. Then, unpack the tarball into an appropriate directory (as you've probably already done). You then need to make sure that PATH environment variable points to the bin/ directory, where several scripts are provided for running Whiley. (don't worry if you don't know what the PATH is, as you can instead run the jar directly --- see below).

With the PATH setup correctly, you should be able to run the wyjc command to compile Whiley programs as follows:

% cd examples % wy compile hello-world.whiley

At this point, you can run the program using the whiley command:

% wy run hello-world Hello World

============================================================================ 3. Building from Source

The compiler for Whiley shipped with the "Whiley Development Kit" is really a compiler framework called the "Whiley Compiler Collection". This is made up of a number of plugins, of which the "WhileyCompiler" is perhaps the most important. This is responsible for compiling Whiley files into the Whiley Intermediate Language (WyIL). Additional plugins (e.g. the "Whiley2JavaCompiler") are responsible for compiling WyIL files for various targets (e.g. JVM bytecode).

As an example, you can build the WhileyCompiler plugin from scratch by cloning this repository. You can build the compiler by running 'ant' at the top level (you need to have Apache Ant installed to do this). At this point, you need to install the new plugin into your distribution of the Whiley Development Kit (see above) in order for it to be recognised by the "wy" command (you can do this by simply copying wyc-vX.Y.Z.jar into the lib/ directory).

Setting up the WhileyCompiler under an IDE should be straightforward, provided it supports Maven. This is because the necessary dependencies for the WhileyCompiler (e.g. other components of the Whiley Compiler Collection) are hosted on Maven central.

============================================================================ 4. Making a Contribution

When making a contribution to the Whiley project, you will need to first sign-off the developers certificate of origin. Please see the CONTRIBUTORS file for more details.