Well - back from a mini "vacation" and what a lot got stirred up. I wanted to clear a few things before hopefully getting together with Joe and anyone else interested next week to talk through the rest. I will keep comments short here, mainly due to time, but I am sure this will not be the end of the story. In brief:
My comments about "being told they can't" were actually uttered with the JCP and not Sun in mind - Joe - you added the [by Sun] modifier to the end (and I find that willingness to claim the link interesting as well). However, later in the same article you mention " we try to err on the side of being conservative (saying "No." by default) first to do no harm, but also to preserve the value of existing Java sources, class files, and programmer skills". I don't know which "we" you are referring too here, but this is definitely the source of the frustration that leads to energetic and talented developers to work outside the traditional parameters and come up with ideas like Lombok. I completely stand by what I say - I have heard "we" just say no to ideas like properties and closures to Java with my own ears, so it's little wonder people find other ways. As listeners to the podcast will know, I am firmly behind Scala as an alternative, and it is an alternative that suits me well personally. I applaud efforts like Lombok and others though, that help improve things and *should* keep everyone happy (after all, they are optional and do not change the core platform or libraries), and yet many of the same "we" that are against change in Java also seem to be against Lombok or even Scala when I talk to them for any length of time. The last point I want to make, and the one I find hardest to swallow, is the inherent assumption that unless someone has the skills or willingness to work on a prototype of their own, they should not have an opinion or at least should not be surprised if that opinion is ignored or refused. Let's think about that another way. We are all developers here (well, I would imagine most are that are reading this). If I applied that attitude to my own job, the scientists and other subject matter experts (who frankly know a lot more than me about the stuff that matters) would never get what they need to do their job. I would be insisting that they write up a prototype before I would implement a solution for them. It is my *job* to translate those wishes into actuality for them. That is the role of a software developer. In other words, they are my customers, and their opinions are actually far more important than my own, since they know what they want out of a genetic calculator, or lab sample tracking system, or whatever else. Can I do everything they want - well, no - I am resource limited just like yourselves, but will you ever hear me tell them that they absolutely can't have something unless they do it themselves, no you won't, nor will I discourage them from working on something themselves. Any time I hear someone working on a compiler telling a developer that they don't need that feature or they don't understand what they are asking for, I cringe. The people using the Java language likely at least have a clue what they need - maybe you can't listen to a single voice, but when enough people ask for something, even if they are not language experts, surely you should still listen? It is great that you guys are language and compiler experts, for the reason that it frees me and others like me to do what we need to do (could you write a human genome risk calculator?). My answer for much of my recent work has been to use Scala, as that solves my problems and meets my needs much better than Java does now, others will find their own way, but requiring everyone to submit prototypes before a proposal will be considered I think is just a handy excuse to retain the status quo, and honestly you can't stand in the way of progress - it will simply find another path. I look forward to talking through these points in more detail soon. Cheers Dick On Sep 2, 8:44 pm, jddarcy <[email protected]> wrote: > After listening to episode 277, I'm led to conclude I'm thought of by > some as one of the "ivory tower guys" who "just says no" to ideas > about changing the Java programming language. > > I have a rather different perspective. > > In November 2006, Sun published javac and related code under the > familiar GPLv2 with Classpath exception. [1] > > Shortly thereafter in January 2007, no less a Java luminary than James > Gosling endorsed the Kitchen Sink Language (KSL) project. [2] In > James' words KSL is "A place where people could throw language > features, no matter how absurd, just so that folks could play around" > since he has "... never been real happy with debates about language > features, I'd much rather implement them and try them out." > > KSL received no significant community response. > > Later in 2007, after the remaining core components of the platform > were published as open source software as part of OpenJDK during > JavaOne, in November Kijaro was created. [4] Kijaro is similar in > spirit to KSL, but not does require contributors to sign the Sun > Contributor Agreement (SCA). Before Project Coin, Kijaro saw a modest > number of features developed, fewer than ten, which is also not a > particular vigorous community response given the millions of Java > developers in the world. > > The earliest posts on what would become Project Coin mentioned the > utility of prototypes, the Project Coin proposal form included a > section to provide a link to an optional prototype, and I repeated > stated throughout Project Coin the helpfulness of providing a > prototype along with a proposal. > > Despite the availability of the OpenJDK sources for javac and the > repeated suggestions to produce prototypes, only a handful of > prototypes were developed for the 70 proposals sent into Project Coin. > > Dick asked rhetorically during the podcast whether alternative > projects exploring language changes were inevitable as the "only > approach given strict control exercised over the JVM [by Sun]." > > IMO, such approaches are inevitable only if Sun's repeated efforts to > collaborate continue to be ignored. > > Classes on compilers are a core component of many undergraduate > compiler science curricula. All the Java sources in the JDK 7 > langtools repository adds up to about 160,000 lines of code and javac > itself is a bit over 70,000 lines currently. These are far from > trivial code bases and some portions of them are quite tricky, but > implementing certain changes isn't that hard. Really. Try it out. > > Dick says toward the end of the opening segment "If people do want to > do this stuff, right now they are being told they can't." > > I certainly do not have the authority to tell others what they can and > cannot do. Indeed, I have advocated producing prototypes of language > changes as a much more productive outlet than whining and pouting that > other people aren't busy implementing the language changes you want to > little avail. Others have already noted in previous messages to this > group the irony of Lombok using the annotation processing facility I > added to javac in JDK 6 as an alternate way to explore language > changes (together with an agent API to rewrite javac internal > classes!) . However, way back before JDK *5* shipped in 2005, we at > Sun recognized that annotation processors by themselves would be a > possible way to implement certain kinds of de facto language changes. > The apt tool and later javac were always designed to be general meta- > programming frameworks not directly tied to annotations; for example, > an annotation processor can process a type containing no annotations > to, say, enforce a chosen extra-linguistic check based on the > structure of the program. > > As an example of what can be done just using annotation processing, > long-time annotation processing hacker Bruce Chapman implemented > "multi-line strings" as part of his rapt project [5]; the value of the > string is populated from a multi-line comment. After repeatedly > outlining how it would be possible to do so on the annotation > processing forum [6], I've gotten around to hacking up a little proof- > of-concept annotation processor based implementation of Properties. > [7] The user writes code like > > public class TestProperty extends TestPropertyParent { > protected TestProperty() {}; > > �...@proofofconceptproperty > protected int property1; > > �...@proofofconceptproperty(readOnly = false) > protected long property2; > > �...@proofofconceptproperty > protected double property3; > > public static TestProperty newInstance(int property1, > long property2, > double property3) { > return new TestPropertyChild(property1, property2, property3); > } > > } > > and the annotation processor generates the superclass and subclass to > implement the desired semantics, including the getter and setter > methods, etc. Using annotation processors in this way is a bit clunky > compared to native language support, but if people want to experiment, > the capabilities have been standardized as part of the platform since > JDK 6. > > It is technically possible to take the OpenJDK sources and construct a > version of javac that accepts language extensions; after all, this is > how we generally evolve the language and also how the JSR 308 changes > were developed before going back into the JDK 7 code base. > Additionally, the IcedTea project and the shipping of OpenJDK 6 in > Linux distributions has provided an existence proof that folks other > than Sun can take the entire OpenJDK code base, add various patches > and additional components to it, and ship it as a product. > > Given the OpenJDK sources Sun has published, subject to the license > and trademark terms and conditions, anyone is free to implement and > use language changes, *as long as* they assume the costs and > responsibilities for doing so. Experimentation has long been > encouraged and experiences from experiments using language changes on > real code bases would certainly better inform language evolution > decisions. Unfortunately, others have generally not done these > experiments, or if the experiments have been done, the results have > not be shared. > > I also do not have the power to prevent others from using non-Java > languages on the JVM or to force others to run anything on the JVM, > nor would I want to exercise such powers even if I had them. Indeed, > for some time Sun has endorsed having additional languages for the > platform and the main beneficiary of John Rose's JSR 292 work will not > be the Java language, but all the non-Java languages hosted on top of > the JVM. > > I do have the authority to speak on what Sun will and will not spend > our resources on in relation to Project Coin, certainly a right any > organization reserves to do with its resources. > > If there are frustrations waiting for Java language changes, I assure > you there are also frustrations working on Java language changes. For > example, I find it frustrating (and self-inconsistent) that people > state "I don't have technical expertise in this area" while > simultaneously expecting their preferences to be selected without any > contribution on their part. [8] > > Finally, going back to a white paper from 1996, the design of Java > quite intentionally said "No!" to various widely-used features from > the C/C++ world including a preprocessor and multiple inheritance. > Again since the beginning, Java admittedly borrowed features from many > other established languages. [9] Given the vast number of potential > ways to change the language that have been proposed, many language > changes will continue to be called and few will continue to be > chosen. In any endeavor there is a tension to balance stability and > progress. For the Java language, given the vast numbers of > programmers and existing code bases, we try to err on the side of > being conservative (saying "No." by default) first to do no harm, but > also to preserve the value of existing Java sources, class files, and > programmer skills. > > There are many other fine languages which run on the JVM platform and > I expect the Java language to continue to adopt changes, big and > small, informed both by direct experiments with prototypes and by > experiences with other languages. > > -Joe Darcy > Project Coin Lead > > [1]http://blogs.sun.com/ahe/entry/javac_open_sourced > > [2]https://ksl.dev.java.net/ > > [3]http://blogs.sun.com/jag/entry/compiler_fun > > [4]https://kijaro.dev.java.net > > [5]https://rapt.dev.java.net/;see also Bruce'shttps://hickory.dev.java.net/ > > [6]http://forums.sun.com/forum.jspa?forumID=514 > > [7]http://blogs.sun.com/darcy/entry/properties_via_annotation_processing > > [8]http://blogs.sun.com/darcy/entry/project_coin_final_five#comments > > [9]http://java.sun.com/docs/white/langenv --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "The Java Posse" group. 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