On Wednesday, July 26, 2006 10:35 AM Ralf Hemmecke wrote: > ... > I believe reflections are not too complicated once we know > how the internal datastructures for domains are. (Yes, yes, > we must look inside the compiler sources, or does anybody > already have a description of how domains are represented > in memory?) > ...
I think the documentation that you need for this is Aldor's abstract machine layer called FOAM. This is where implementation details such as you describe are specified. This abstract machine is implemented in Lisp, Scheme, and in a C runtime system. I believe that the program code that is generated by Aldor before being converted to real machine code is accessible in the .asy and .ao files. If we had to parse the output of the compiler in order to know what it was doing, then it seems to me that this a better and fully portable place to look rather Lisp or intermediate C code. To fully implement reflects in Aldor it might be necessary to provide some new operations at the FOAM level and in particular in the RunTime support library (which is written in Adlor). Here is a useful introduction: http://www.orcca.on.ca/~ldragan/aldor/fp/fp.html Apparently there is a detailed reference [6]: Stephen M. Watt and Peter A. Broadbery and Pietro Iglio and Scott C. Morrison and Jonathan M. Steinbach, FOAM: First Oder Abstract Machine which is referenced here www.csd.uwo.ca/~watt/pub/reprints/2005-mc-towers.pdf but I have not been able to find it online anywhere. But even without extending the RunTime support it may be possible to use the approach discussed in the Aldor Users Guide to make "data self-identifying". See section 7.1: "Aldor, on the other hand, adopts the ``Types on Variables'' approach, and values are not normally self-identifying.... For example, self-identifying data may obtained by incorporating types in the values." By this I presume is meant something like this: ----------- MyDom: with describe:Generator Category add2:(MyDom,MyDom) -> MyDom sub2:(MyDom,MyDom) -> MyDom neg: MyDom -> MyDom == add import from Integer Rep == Integer describe:Generator Category == generate yield with {add2:(MyDom,MyDom)->MyDom} yield with {sub2:(MyDom,MyDom)->MyDom} yield with {neg:MyDom->MyDom} add2(x:%,y:%):% == per(rep(x) + rep(y)) sub2(x:%,y:%):% == per(rep(x) - rep(y)) neg(x:%):% == per(-rep(x)) ---------- Unfortunately this code causes a compile error in the current version of the Aldor compiler. It also raises the question of how reflected information should be represented in Aldor. Perhaps a List would be better than a generator? Unfortunately although the above code using List does compile, it does not seem to work as expected at runtime. See http://wiki.axiom-developer.org/SandBoxAldorSemantics#msg20060726062837- [EMAIL PROTECTED] But in principle this would allow one to write something like for s in describe$MyDom repeat if MyDom2 has s then ... etc. and maybe (with some extension to the syntax) even to instantiate new domains from categories defined like this: with { s for s in describe$MyDom where MyDom2 has s } Regards, Bill Page. _______________________________________________ Axiom-developer mailing list Axiom-developer@nongnu.org http://lists.nongnu.org/mailman/listinfo/axiom-developer
