> What Macromedia have done > with 8.5 is to completely and totally change the structure of byte code, > though the input syntax is pretty much the same as AS2.0. Reverse > engineering the bytecode is difficult without a description either of > the VM architecture, or of the file format. There are many blocks of > data inside the bytecode that just cannot be interpreted without reverse > compiling the VM or the Flex Builder application, both of which may > leave the implementor and users open to litigation.
I wouldn't say that. Of course it's not easy, but it's not impossible, either. And as the Irrelevant Elephant said, it's kinda fun :) Sure, at least knowing something about the architecture would help a lot. But figuring out single bytecodes it totally possible by doing little changes (say, a plus instead of a minus). The more gets figured out that way, the easier the rest becomes. It's a bit like a puzzle, the more pieces you have in place the easier it gets. mark On 10/25/05, Alex Bradley <[EMAIL PROTECTED]> wrote: > Having had a quick look at AS3.0 I have to say that this is a completely > different beast from ActionScript 2.0. AS 2.0 compiles to Action Script > 1.0 and this has been around in same form since the beginning of the > Flash plugin - the changes in each version have been incremental and > have not changed fundamentally since Flash 5. What Macromedia have done > with 8.5 is to completely and totally change the structure of byte code, > though the input syntax is pretty much the same as AS2.0. Reverse > engineering the bytecode is difficult without a description either of > the VM architecture, or of the file format. There are many blocks of > data inside the bytecode that just cannot be interpreted without reverse > compiling the VM or the Flex Builder application, both of which may > leave the implementor and users open to litigation. If Adobe/Macromedia > are serious in their support for Open Source, now might be a good time > for them to indicate whether they will be making their VM or file specs > open-source in an patent-unencumbered way and when this will happen. > Given the the Flash 8 format has not yet been released, I wouldn't hold > my breath. I'd love to be proven wrong... Mike?? > > Still, I would work on the assumption that the format will be published > in some form within the next 12 months. If this assumption is correct, > there is still a huge amount of work that can be done between now and > then. As maybe the only other person on the list that has written a full > ActionScript 2.0 compiler (unless some Macromedians are lurking > somewhere) I respect what Nicolas has to say about OCAML (I've > programmed in Prolog for three years). Indeed, the speed with which > MTASC was written is a testimony to this. However this has its own pros > and cons. If more than one person was working on MTASC I believe it > would have many more features than it currently does, and there would be > a much greater dialog between the authors and the community. The choice > of OCAML retricted this (though so did Nicolas' choice not to open up > the development tree). Other than Ralf's work with HamTASC, there have > been no other user contributions to MTASC (this may also be so that > MTASC can be dual-licensed?). > > I also don't believe compilers should be just seen as standalone > programs anymore. I went from coding in 'vi', to JBuilder, to Eclipse, > each representing a much greater degree of integration between the > process of coding and the process of software development and each > increased mmy productivity many-fold. Having a extensible stateful > compiler that directly embeds into your application is a natural > progression and I see many benefits of this approach that more than > compensate for having to develop in a more general-purpose language > including things such as incremental compilation or caching > (KineticFusion can recompile most SWFs in less than a second even after > modifying classes - the key word here is 'recompile'). The Flex compiler > for example, including the ActionScript bits, is written in Java and my > understanding is that it performs very well. > > Have as ASDT folks not already written an AS2.0 lexer/parser for their > Eclipse plugin? My recommendation would be to concentrate on the > lexer/parser/semantic analyser for as long as possible. Ensure that as > much semantic information as possible is extracted and represented as > object references are used in a much more complex way in AS3.0. The code > generation bit should probably be the last piece of the puzzle and could > be completed in a week by a couple of skilled coders if the > documentation is available. I'm not sure the alternative approach of > working backwards from the bytecode is a good use of resources for the > GENERAL community (I think it's good for individuals to look at so they > can still give semantic requirements feedback to the semantic module > people). And remember, we're still talking about 12 months before there > is going to be any kind of Flash 8.5 presence out there. > > Just my 2 cents (I'll go back to lurking now!) > > Alex -- http://snafoo.org/ jabber: [EMAIL PROTECTED] _______________________________________________ osflash mailing list [email protected] http://osflash.org/mailman/listinfo/osflash_osflash.org
