dscript

This is a little scripting language I put together when I was heavy into c++ development and studying compiler theory. I haven't touched this code since it was finished up and pushed out to the boost.spirit mailing list in November of 2003. Below are the original emails announcing its completion.

Note: This does not build on current compilers. The version of boost that it uses is horribly outdated. I'm going to try to update this to current c++ compilers (g++, vs 2010/2012), but no guarantees

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Subject: [Spirit-general] Scripting Language
From: "Bryan Ross" ~~<[email protected]>~~ [email protected]
Date: Wed, 19 Nov 2003 18:46:04 -0800
To: <[email protected]>

Hey all.

Well, here it is. It's far from complete, and not 100% debugged, but it works. There's a sample main.cpp in the archive that will compile and execute the included test.txt file, which should demonstrate the syntax of the language fairly well. Also, the entire spirit grammar is in compiler.cpp, which will explicitly explain the syntax of the scripting language.

I'd love for all of you to take a look and give me any possible feedback. Also, don't hesitate to rip it apart or improve on anything you see. The fact of the matter is, I don't have much time available right now to finishing and polishing it up. I'd just figure I'd get something out there that actually functions that others could take a look at and see how spirit may be used for designing and implementing a scripting language.

I wanted to upload this to http://spirit.sourceforge.net/dl/, but I forgot my login password, and the password recovery system is borked, so I'll just post it to the newsgroup.

Also, to re-iterate, here is the post I made earlier, with some more info on the language:

PS: Joel, I've updated the files all to sport a very slightly modified version of the spirit license.

Bryan Ross [email protected] [email protected]

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-----Original Message-----
From: Bryan Ross [[email protected]]
Sent: Thursday, November 13, 2003 10:15 AM
To: [email protected]
Subject: [Spirit-general] script language sample [UPDATE]

Hey all

This is just a heads up that I'm still working on this, and it's almost complete. I decided to go with a parse tree instead of an AST, which unfortunately added a lot of code to the compilation process, but IMO makes the compiler more analogous to the parser and it also seems a bit easier to follow.

I don't know if you'd call this a "simple" scripting language sample though (almost 4000 lines of code).

The language has been dubbed "DScript".

A few features:

• C like syntax (what else?
• Procedural language that supports both script defined and host environment functions.
• Multi-dimensional arrays.
• 3 basic types: string, int, and double
• Variables are typeless
• Language defined local and global variables
  • %var (local variable, gets cleaned up at exit of current function)
  • $var (global variable, sticks around until manually deleted)

Some notes on implementation:

• Uses nothing but Spirit, Boost and the STD C++ library. Should be fully platform independent.
• Embedding into a host application is dead simple:
  1. Include the source files in your project (or compile it into a .lib file and link with that)
  2. Include the dscript.hpp header
  3. create a dscript::context object
  4. call the methods of that context object to load and execute scripts.
• Script code is compiled into byte-code that is executed by the runtime.
• Script files may be compiled into a byte-code binary format for faster loading time
• dscript::context objects are fully encapsulated. You can have any number created at any time.
• Script functions may be called by the host application through the context object.
• Errors generated are output to a specified std::ostream

Hopefully this should be done in the next couple of days, and then I'm going to clean it up and prepare it for release. I'm planning on making it dependent on spirit 1.8, so at the very least I'll be waiting until that release before this "goes gold".

DScript will be released under the GNU Public License (GPL)

Once fully finished, I'll submit it to the spirit application repository, and if it's good enough, maybe you guys could package it as an example.

Bryan Ross [email protected] [email protected]