Thanks Matt and Karsten. You've clarified the issues for me quite nicely. IIUC, again, the clojurescript compilation process is taking place exclusively in a clojure/jvm environment. If that is the case, macro expansion must also, necessarily, occur in that clojure/jvm environment. If that is the case, what difference does it make if defmacro appears in a file with a .cljs extension?
It seems to me that the difference is that it greatly complicates the compiler. Just looking at function definitions, including executing code within defmacros, there are three cases. 1) Pure agnostic clojure, 2) functions with java interop, and 3) functions with js interop. (And, I suppose, functions with both forms of interop, which can be rejected immediately.) 2) is only valid during macro expansion, 3) is valid wherever macro expansion is not being perfomed, and 1) is always valid. The compiler could, I imagine, be obliged to sort that lot out, effectively creating .clj files on the fly, and allowing all agnostic code to fall thorough to code emission, where redundant, macro only, functions can be dealt with by dead code elimination. However, as I said, that would complicate the work of the compiler. Thanks again for the feedback on this. On Tuesday, 10 March 2015 06:13:02 UTC+10, Matt Greer wrote: > How could macros written in ClojureScript execute if ClojureScript isn't self > hosted? There needs to be some kind of runtime to execute the macro, and > currently the only runtime available is the JVM. > > > > On Wed, Mar 4, 2015 at 9:03 PM, Peter West <[email protected]> wrote: > On Thursday, 5 March 2015 05:31:49 UTC+10, Stuart Sierra wrote: > > Thanks to all for the replies. > > > > Stuart, I wasn't thinking about self-hosting; merely about unifying the > experience under Clojure and ClojureScript, wrt macros. Some work has > already been done towards this, and I was wondering whether it were feasible > to integrate defmacro into the CLJS compiler. I thought there may be > subtleties around the fact that CLJS appears to be an essentially AoT > environment. > > > > In the event that there are no structural impediments, we might look forward > to such a full integration of defmacro some time down the track. I think it > would be a boon for the wider acceptance of CLJS. > > > > > > > On March 3, 2015, Peter West wrote: > > > > Macros eventually all expand to CLJS-compatible code. > > > > Currently, IIUC, both macro definition and expansion are > > > > handled by the Clojure compiler, with the resulting code > > > > (presumably CLJS compatible) being handed back to the > > > > ClojureScript compiler. Was this simply a convenience to > > > > get CLJS working with a minimum of fuss, or are there some > > > > structural impediments? > > > > > > > > > Mostly, I think, it was the quickest path to bootstrap the > > > ClojureScript compiler. Clojure already had a reader and > > > macro expander, so ClojureScript used them. > > > > > > In Rich Hickey's original design, ClojureScript was not > > > intended to be self-hosting without the JVM. The past few > > > years of work have brought ClojureScript closer to the > > > *possibility* of self-hosting, but it hasn't been a priority > > > for most of the major contributors. > > > > > > -S > > > > -- > > Note that posts from new members are moderated - please be patient with your > first post. > > --- > > You received this message because you are subscribed to the Google Groups > "ClojureScript" group. > > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > > To post to this group, send email to [email protected]. > > Visit this group at http://groups.google.com/group/clojurescript. > > > > > > -- > > > Matt -- Note that posts from new members are moderated - please be patient with your first post. --- You received this message because you are subscribed to the Google Groups "ClojureScript" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/clojurescript.
