XP to JS compiler / XP JS microkernel

This experiment tries to see whether the XP Framework could be based on JavaScript runtimes in the future. Paired with the XP compiler, its PHP language parser and the generator to emit JavaScript, and maybe together with porting some of PHP's string and array functions, we would be able to exchange the PHP platform we currently depend on for something else.

Demo class

// {{{ Hello
Hello = define('Hello', 'lang.Object', function Hello () { });

Hello.main = function Hello$main(args) {
  if (args.length < 1) {
    throw new lang.IllegalArgumentException('Argument required');
  }
  util.cmd.Console.writeLine('Hello ', args[0]);
}
// }}}

NodeJS

Node.JS is the V8-based JavaScript engine which is becoming increasingly popular. Even with its pre-1.0 status, sites such as GitHub use it in production. See http://nodejs.org/

Getting started

$ node tools/node.js Hello "World"
Hello World

$ node tools/node.js Hello
*** Uncaught exception lang.IllegalArgumentException(Argument required)
  at IllegalArgumentException("Argument required") [line 5 of IllegalArgumentException.js]
  at Hello.main(array[0]) [line 6 of Hello.js]
  at Method.invoke(null, array[1]) [line 26 of Method.js]
  at __main() [line 194 of node.js]

Setting up the compiler

You need the branch "node" of my xp-language fork checked out:

$ git clone -b node git://github.com/thekid/xp-language.git xp.node
Cloning into xp.node...
[...]

Then, you need to add this to the use line in your xp.ini file. This file will usually be in ~/.xp/xp.ini or ~/bin/xp.ini. Add the path to the "compiler" subdirectory of the "xp.node" directory from above to the end of this line, prefixed by the platform's path separator character. For example, this will work on Un*x platforms (in Windows, use semicolons):

-use=~/devel/xp/core:~/devel/xp/tools
+use=~/devel/xp/core:~/devel/xp/tools:~/devel/xp.node/compiler

You're all set to go.

Compiling

To compile classes from XP language to XP JS, simply invoke the xcc command as follows:

$ xcc -e node Hello.xp
[.]
Done: 1/1 compiled, 0 failed

Then, run it as seen above.

Class path

For a start just put all the classes in the current directory. Later on, when you want to start sorting stuff out, you can place compiled classes anywhere in the class path. The class path is compiled from the paths listed in the .pth files (as with the XP Framework). To get an overview of all currently registered class paths, execute the entry point without arguments:

$ node tools/node.js
XP JS Microkernel 0.9.1 { Node 0.6.14 & V8 3.6.6.24 } @ Windows_NT 6.1.7600 (ia32)
Copyright (c) 2011-2012 the XP group
lang.FileSystemClassLoader<C:\cygwin\home\friebe\devel\xp-js\core\src\main\js>
lang.FileSystemClassLoader<C:\cygwin\home\friebe\devel\xp-js\test\src\main\js>
lang.archive.ArchiveClassLoader<C:\cygwin\home\friebe\devel\xp-js\lib\tools.xar>
lang.FileSystemClassLoader<C:\cygwin\home\friebe\devel\xp-js>

Testing

The classes provided in the microkernel are tested by unittests in the directory with the same name. To run these tests, invoke the following command:

$ node tools/node.js Unittest unittests.*
[........................................................................
.......................................]

OK: 111 run, 111 succeeded, 0 failed
Memory used: 12728 kB
Time taken: 0.016 sec(s)

The tests are written in XP language. Any changes made to the *.xp files need to be recompiled to JavaScript before executing. This can be accomplished by running xcc -e node unittests/*.xp.

Contributing

If you would like to contribute, you can do it the GitHub way by opening issues or pull requests. To see where help is needed, check the implementation status document

Happy hacking!

xp-js

README.md