On Fri, 05 Aug 2011 06:36 -0500, "Aaron Faanes" <[email protected]> wrote: > I was reading the m0 spec and had a couple thoughts/questions as I read:
Thank you for taking the time to comment on them. > > * The term "x" is used to indicate an argument's value is ignored. In > a few other languages, a single underscore is commonly used for this > purpose. It's a little unusual to see, but I think the underscore > indicates "ignore me" better than x. 'x' was the first thing that came to mind, but "_" does seem a bit more readable. We won't be writing a whole lot of M0 code once Mole is ready, but we will be reading quite a bit of it, so readability will be valuable (especially if it's an easy change like this). I'll add the change to my todo list. > > * I also noticed that labels cannot begin with underscores (at least, > according to the provided regex). Is this intentional? I know in some > dark corners of the world, prefixing a label/function with underscores > indicates that it's more magical than usual. +0. I'll accept a patch, but labels are pretty internal. Relying on their names (or any aspect thereof) should be avoided. I wasn't explicitly thinking that labels shouldn't start with an underscore, but I don't see much reason why they should either. > > * Can copy_mem copy to/from GC memory to sys-allocated memory? I'd > assume so, but I feel that this capability should be made explicit. Yes. I'm not sure why this wouldn't be the case. I'll add it to my todo list to make this explicit. > > * The discussion about registers and the discussion of spilling should > probably be closer together, in a lexical sense, since they seem > related. todo'd. A general reorganization of the pdd has been in order for a while. I would reject a patch that did it for me. ;) > > * Regarding registers, is it acceptable/possible for a M0 VM to > contain more than 256 registers, to prevent spilling? No, but I think it will be more common to need far fewer than 256 registers. If we don't write explicit tests for register spilling, I expect that only very unusual code will use it. > > -- > Aaron Faanes <[email protected]> > _______________________________________________ > http://lists.parrot.org/mailman/listinfo/parrot-dev > Christoph _______________________________________________ http://lists.parrot.org/mailman/listinfo/parrot-dev
