Do you have any idea about the reason that the Clojure implementation was done this way - when it obviously seems a bit limited and also slower than necessary? Just curious if there's some historical context.
On Tuesday, January 14, 2020 at 11:58:17 AM UTC-5, Nathan Marz wrote: > > The speedup comes from proxy+ directly overriding methods with the > provided implementation, while Clojure's proxy has additional indirection. > For example, if you do (proxy [Object] [] (toString [] "hello")), the > bytecode for toString is: > > public java.lang.String toString(); > > 0 aload_0 [this] > > 1 getfield user.proxy$java.lang.Object$ff19274a.__clojureFnMap : > clojure.lang.IPersistentMap [16] > > 4 ldc <String "toString"> [52] > > 6 invokestatic clojure.lang.RT.get(java.lang.Object, > java.lang.Object) : java.lang.Object [36] > > 9 dup > > 10 ifnull 28 > > 13 checkcast clojure.lang.IFn [38] > > 16 aload_0 [this] > > 17 invokeinterface clojure.lang.IFn.invoke(java.lang.Object) : > java.lang.Object [55] [nargs: 2] > > 22 checkcast java.lang.String [57] > > 25 goto 33 > > 28 pop > > 29 aload_0 [this] > > 30 invokespecial java.lang.Object.toString() : java.lang.String [59] > > 33 areturn > > Clojure keeps the implementations in a map, and for every dispatch it does > a map lookup by the method name. This is also why it can't handle > overriding the same method name with different arities. > > For (proxy+ [] Object (toString [this] "hello")), the bytecode is: > > public java.lang.String toString(); > > 0 aload_0 [this] > > 1 getfield user.proxy_plus5358.toString5357 : clojure.lang.IFn [19] > > 4 aload_0 [this] > > 5 invokeinterface clojure.lang.IFn.invoke(java.lang.Object) : > java.lang.Object [30] [nargs: 2] > > 10 checkcast java.lang.String [32] > > 13 areturn > > The implementation function is stored as a field, so the cost of dispatch > is a field get rather than a map lookup. > > Clojure's proxy also overrides *every* available method in all > superclasses/interfaces, while proxy+ only overrides what you specify. So > proxy+ generates much smaller classes than proxy. > > > On Tuesday, January 14, 2020 at 10:30:32 AM UTC-5, Brent Millare wrote: >> >> I skimmed the code, I don't really understand how it makes it faster over >> proxy. Is it the generated ASM is better? What's the in-a-nutshell >> description of how it works? >> >> On Monday, January 13, 2020 at 1:28:46 PM UTC-5, Nathan Marz wrote: >>> >>> No differences in behavior except for API being like reify. It >>> integrates with AOT and can be consumed just like any other class. No idea >>> how it interacts with Graal. >>> >>> On Monday, January 13, 2020 at 12:29:35 PM UTC-5, John Newman wrote: >>>> >>>> Bravo 👏👏👏👏👏 >>>> >>>> Are there any differences in behavior to be aware of? AOT, Graal, >>>> consuming proxy+ classes from vanilla clojure classes? >>>> >>>> On Mon, Jan 13, 2020, 11:47 AM Nathan Marz <natha...@gmail.com> wrote: >>>> >>>>> proxy+ is a replacement for Clojure's proxy that's faster and more >>>>> usable. proxy has a strange implementation where it overrides every >>>>> possible method and uses a mutable field to store a map of string -> >>>>> function for dispatching the methods. This causes it to be unable to >>>>> handle >>>>> methods with the same name but different arities. >>>>> >>>>> proxy+ fixes these issues with proxy. Usage is like reify, and it's up >>>>> to 10x faster. >>>>> >>>>> *Repository: *https://github.com/redplanetlabs/proxy-plus >>>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "Clojure" group. >>>>> To post to this group, send email to clo...@googlegroups.com >>>>> Note that posts from new members are moderated - please be patient >>>>> with your first post. >>>>> To unsubscribe from this group, send email to >>>>> clo...@googlegroups.com >>>>> For more options, visit this group at >>>>> http://groups.google.com/group/clojure?hl=en >>>>> --- >>>>> You received this message because you are subscribed to the Google >>>>> Groups "Clojure" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send >>>>> an email to clo...@googlegroups.com. >>>>> To view this discussion on the web visit >>>>> https://groups.google.com/d/msgid/clojure/6d9bf48a-c5b5-417a-9f66-aa494cc38346%40googlegroups.com >>>>> >>>>> <https://groups.google.com/d/msgid/clojure/6d9bf48a-c5b5-417a-9f66-aa494cc38346%40googlegroups.com?utm_medium=email&utm_source=footer> >>>>> . >>>>> >>>> -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/clojure/a3cb68bc-71d9-44a4-b27e-ad00a3958be8%40googlegroups.com.
