As for #2, note that Groovy code is compiled to bytecode as any other Java class. I use DCEVM + IntelliJ IDEA’s groovy gragent for hotswapping Groovy code and it works reasonably well. Not as good as Java, but Groovy works pretty well. It works well if you make sure not to add or remove closures when hotswapping. The vast majority of our code is static compiled. For reasons of performance, hotswapping, and debugging capability we use static as much as possible and try to reduce closures in use, even though they are the most powerful feature, we don’t use closures for example like with “each” method, instead we use plain for loops. Unfortunately, for some newer code now that we are on Java 8 where we used to have heavy closures code we instead use a Java helper class so we can use Streams API, which does not work well in Groovy, and also has the performance and hotswapping benefits.
If I was to consider forcing all Groovy code to static compilation at this time, I would seriously consider Kotlin instead of Groovy. Kotlin did not exist when we started our projects. That said, I have found no other JVM solution for dynamic consumption and production of webservices and schema-less structured data that compares to Groovy, and a hybrid Java+Kotlin+dynamic Groovy project is at best overcomplicated and I’m not even sure circular dependency is possible between the languages, therefore Groovy is still our language of choice for pairing with Java. #4 is already implemented. In JVM the common language is bytecode and Groovy is a syntax sugar over bytecode, and bytecode already has a mapping of instructions to source code which is understood already by all JVM debugging tools. To do literally what you suggest would involve discarding the vast majority of the Groovy compiler and rewriting it to output Java code, which might not look much better than fernflower’s output but with improved variable names and possibly transfer of Javadoc. The other issue is that Groovy is a lot more than Java++ and requires a lot of helper code, particularly the MOP with dynamic groovy, that the Java output would not look like any kind of idiomatic Java that developers would want to work with. Jason From: Paco Zarate [mailto:conta...@nazcasistemas.com] Sent: Monday, October 16, 2017 2:36 PM To: users@groovy.apache.org Cc: Paul King <pa...@asert.com.au> Subject: Re: Consider statically typed/compiled as default for Groovy 3.0 I really like this topic. 1) Groovy syntax is incredible readable/maintainable. I take Groovy code from years ago and I am able to make changes easily. Thank you guys for this! 2) The dynamic portion of Groovy is interesting but it has some limits: when you are coding you need to recompile to see a change on a single line. Is it possible to have a the code recompiled on the fly? Is it possible in Groovy to step back during the debug? And finally, would be a way to be debugging Groovy code, hit a breakpoint, modify some already executed code on the fly, step back and rerun it? I guess all this is more tooling related than language related, but I would appreciate your opinions. 3) Have you seen the Smalltalk;s Pharo environment? they have visual tools to access and modify the Smalltalk app internals. For example, see all the objects and modify then in the fly, include more code, save the state of the app (image) and reload it later. It is really interesting and I wonder if Groovy could use its dynamic nature that way. 4) For the static portion of Groovy: Have you think in the Typescript way of doing things? They are the "javascript++" but they have been doing it though transpiling to a very readable javascript. The option I see, would be to have Groovy generating Java code + maps for debugging. The use case would be: you work in a Java company, use Groovy to develop and then deliver to your company very readable Java code. I guess this may be doable with CompileStatic Groovy code and have a chance to apply too to generate Android Java code. On Fri, Oct 13, 2017 at 7:14 AM, Cédric Champeau <cedric.champ...@gmail.com<mailto:cedric.champ...@gmail.com>> wrote: Wise words, Paul. I would also very much prefer to see progress in the Java 9 area rather than this, or even the parser. It's much more relevant to the future of Groovy IMHO. Because, as the ticket explains, there's already ways to enable this feature (even if a bit cumbersome). It's really of that importance, then a pull request, accepted through a VOTE, would certainly be the fastest way to get this. 2017-10-13 15:11 GMT+02:00 Paul King <pa...@asert.com.au<mailto:pa...@asert.com.au>>: I think most committers are also keen on making progress in the directions you describe. Not along the lines of watering down Groovy's dynamic capabilities but certainly in terms of making Groovy's static nature as hassle free as possible to use. Having said that, we have limited resources, so we need to prioritise and do a limited numbers of things well rather than half do lots of things. Most of us have our own long list of technical issues that we think need working on (jdk9 support, new parser, bugs we know of in static type checking, many other features we'd like, etc.), so if you aren't seeing a lot of traction for this idea, it is possibly because we see a big list of things that would be needed to be sorted out to do this well and we are weighing up that list with our already long todo lists. Perhaps we wear our technical hats too much and should put on our marketing hats a bit more - who knows. All I can suggest to you is that Apache Groovy follows the Apache do-ocracy culture. If anyone picks off a small piece of the puzzle and advances it forward, it is likely to progress. But it's not guaranteed, so you are doing the right thing by discussing on the mailing lists. If you still don't get traction, start again with a smaller step. Cheers, Paul. On Fri, Oct 13, 2017 at 6:30 AM, MG <mg...@arscreat.com<mailto:mg...@arscreat.com>> wrote: blackdrag suggested to move this https://issues.apache.org/jira/browse/GROOVY-8329 discussion from Jira to this list, so I am replying here: I agree with Endre Stølsvik: I think Groovy should strengthen its language support for statically compiled use, and I agree it should move towards making statically using it as hassle free as possible. I think Endre has already made some good points why this would be a good idea, so I am just going to add that I am convinced that Groovy would not be at 3% of the languages used after Java, but at > 30% (basically everyone that could freely pick a language for commercial projects besides Java would be using it) if it would fully be the Java++ it in fact is - in my perception what kept it back was the fact that it "is slow" (true > 10 years back), that it is just "a script language" (never true afaik) - and that it "is a dynamic language" (no longer true, but...). When I picked Groovy for the project I work on, I did so despite it was dynamic, not because of that (the static Groovy compiler that someone in Russia had built at the time helped in the decision...). Being able to be dynamic in a language is a powerful feature, but one that is needed only in special cases. Otherwise Groovy would already rule the Java world ;-) Being able to have a very simple configscript that qualifies every class with @CompileStatic is great (http://docs.groovy-lang.org/latest/html/documentation/#_static_compilation_by_default), but it is not simple/easy enough: I agree there should be a "one click" option to turn all of Groovy to using static compilation by default. Some ways to achieve this: # Make a "static Groovy" download available (might just be based on "including" the @CompileStatic configscript above) # Compiler switch # Choose during installation # Express through the Groovy source file extension: ## *.groovy ... use configured default ## *.groovyd ... dynamic ## *.groovys ... static (alternatives: *.groovys, *.sgrv, *.grvs) The last option has the advantage, that everybody can use it easily everwhere (Shell, IDE, ...), but the disadvantage that all the Groovy examples out there use *.groovy, which would again might give the impression to people that Groovy is "mostly a dynamic language". Maybe a combination of people picking the default mode (dynamic/static) at download/install time, with the extension approach would work best. (That the Groovy compiler will try to compile any file with any extension is OK. In that case I would suggest the fallback if the extension is not known is dynamic compilation, for backward compatibility reasons. Configuring extensions to mean dynamic or static compilation would of course also be an option). Or the Groovy compiler could throw if no --static or --dynamic compiler switch was given ? That would force everyone to make a deliberate decision... ;-) Just a quick brainstorming mail, to hopefully get the discussion going, Markus This email message and any attachments are for the sole use of the intended recipient(s). Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message and any attachments.
