On Thu, Oct 8, 2009 at 11:25 AM, Don <nos...@nospam.com> wrote: > Jarrett Billingsley wrote: >> >> On Thu, Oct 8, 2009 at 4:00 AM, Don <nos...@nospam.com> wrote: >> >>>> So it looks to me like the mechanics of it are basically identical. >>>> Just Nemerle's syntax is nicer. >>> >>> Only with trivial examples. With more complicated examples they look less >>> identical. I'm basing my views on pages like this: >>> >>> http://nemerle.org/Macros_-_extended_course._Part_2 >>> >>> Unless I'm totally misunderstanding this, it looks to me as though >>> Nemerle >>> macros are implemented as compiler plugins. >>> All the advanced facilities are obtained by exposing the compiler's API! >> >> Well they're not.. "plugins" per se as much as "compiled modules." >> Okay yes that's basically a plugin :P But it's not that different from >> D, where you use compile-time executed functions to do the same sorts >> of things. It's just that you precompile those functions instead of >> having the compiler "compile" them on every compilation. > > No. CTFE is simply taking constant-folding to its logical conclusion.
All the Nemerle *implementation* is doing differently here is having you precompile the functions that are to be executed at compile-time. That's it. The resultant semantics are utterly the same. You are running code at compile-time, it doesn't matter if that code is running on the hardware or in a VM in the compiler. >> But really, I don't see how this is significantly different from >> hooking into the D compiler's internals with __traits, .stringof, >> .mangleof and the like. So it uses an object-oriented API to access >> those things instead of ad-hoc hacks. And? > > The thing I think is elegant about D's approach, ugly as the syntax > currently is, is the complete separation of the lex - parse - semantic - > codegen phases. And I think CTFE is fantastic (and I plan to fix it so it > works properly). Think about how easy it is to explain. And Nemerle's macros are *hard* to explain? They're a function that executes at compile time. Oh, wait! That's exactly the same as CTFE. >> I don't know how you can trash Nemerle's approach while leaving D's >> unmentioned. > > What do you mean, 'unmentioned'? Hey, you started this by trashing D's > approach! I'm not talking about me. I'm talking about you. I don't know how you can trash a language with macros that were designed *from the bottom up* to be used as such and which are treated as first-class citizens, while not admitting the hilariously ad-hoc nature of a language where macros fall out as a consequence of a number of other, ill-defined poorly-implemented unorthogonal features. Sigh, I'm done.
