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the OpenJDK group at Oracle is growing

p.p1 {margin: 0.0px 0.0px 12.0px 0.0px; font: 12.0px Times} span.s1 {text-decoration: underline ; color: #0000ee}The OpenJDK software development team at Oracle...

p.p1 {margin: 0.0px 0.0px 12.0px 0.0px; font: 12.0px Times} span.s1 {text-decoration: underline ; color: #0000ee}The OpenJDK software development team at Oracle is hiring. To get an idea of what we’re looking for, go to the Oracle recruitment portal and enter the Keywords “Java Platform Group” and the Location Keywords “Santa Clara”.  (We are a global engineering group based in Santa Clara.)  It’s pretty obvious what we are working on; just dive into a public OpenJDK...

suppressing warnings this month

The OpenJDK community just had a nice sprint cleaning up warnings in JDK code. I did my bit; it was fun.Two questions came up during reviews, one about the...

The OpenJDK community just had a nice sprint cleaning up warnings in JDK code. I did my bit; it was fun.Two questions came up during reviews, one about the equivalence of wildcards and named type parameters, and one about the best way to handle creation of an array of generic element types.Here's the quick summary of how to write arrays of generics:@SuppressWarnings("unchecked") // array creation must have wildcardList<String>[] lss = (List<String>[]) new List<?>[1];In the...

JSR 292 support in javac

In order to work with dynamic types, method handles, and invokedynamic I have made some provisional changes to javac as part of the Da Vinci Machine Project....

In order to work with dynamic types, method handles, and invokedynamic I have made some provisional changes to javac as part of the Da Vinci Machine Project. The mlvm wiki has a full description for Project COIN. It is most desirable, of course, to program invokedynamic call sites as Java expressions, not just ASM code, and that's what those langtools patches are for.The essential features are four: The type java.dyn.Dynamic will accept any method call and turn it into an...

Scope ambiguities between outer and super

Or, combing out a stubborn tangle.Gilad Bracha has published a nice paper reviewing an interaction between inheritance and block scoping, specifically the...

Or, combing out a stubborn tangle.Gilad Bracha has published a nice paper reviewing an interaction between inheritance and block scoping, specifically the problem of deciding whether a simple (unqualified) name comes from a superclass or from an outer scope. This issue only arises in languages which can nest classes within block scopes, and intermix regular definitions with subclass definitions. This issue arose for Java when we added nested classes.Similar problems arise any...

June Language Dynamics

Charles Nutter has started an interesting Google Group which is worth the attention of language wonks:  http://groups.google.com/group/jvm-languagesI recently...

Charles Nutter has started an interesting Google Group which is worth the attention of language wonks:  http://groups.google.com/group/jvm-languagesI recently spent a pleasant hour thinking about Common Lisp on the JVM; see this thread:  http://groups.google.com/group/jvm-languages (Kicking off: Jatha)Meanwhile, the JSR 292 Expert Group will be working this summer on a simplified POC (proof of concept) that can serve as the basis for coordinated experiments in JVM and...

Longjumps Considered Inexpensive

Whenever the conversation about full closures (on any platform) gets to a certain level of detail, the question of closing over branch targets comes up. For...

Whenever the conversation about full closures (on any platform) gets to a certain level of detail, the question of closing over branch targets comes up. For example, we know what break means in a regular for loop. But suppose that loop is expressed as an internal iterator; that is, suppose the loop body is packaged into a closure and passed to a loop-driver method. Then the same break statement has to do something scary to return control past the loop-driver method.Every Java...

JSR 292 Deep Dive Notes

5/09/2007, 2:00-3:00, Westin Civic CRAttending:John Rose (host, Hotspot VM)Oti Humbel, Charlie Groves, Tobias Ivarsson (Jython)Thomas Enebo, Charles Nutter...

5/09/2007, 2:00-3:00, Westin Civic CRAttending:John Rose (host, Hotspot VM)Oti Humbel, Charlie Groves, Tobias Ivarsson (Jython)Thomas Enebo, Charles Nutter (JRuby)John: JSR 292 needs insight into pain points implementing dynamic langs. Our basic thought: Method invocation in the JVM is too Java-specific. We probably need one more kind of invocation which is not type-bound, and allows systems to adapt to mismatches between caller and callee signatures. Other requirements may...

Whither JSR 292?

As of March I'm the chair of JSR 292. Judging by individual contributions and comments I've received, the committee is eager to start digging into details.  But...

As of March I'm the chair of JSR 292. Judging by individual contributions and comments I've received, the committee is eager to start digging into details.  But we have not yet done so in a coordinated way.  Part of the problem is problems with the JCP website, and part is me having to shovel other stuff off of my plate at Sun.The committee is rather small, and composed largely of dynamic language implementors familiar with the JVM. I really like this setup. I expect we'll be...

Autonomous Methods for the JVM

Byte-coded methods in the Java Virtual Machine are perfectly suited for their main role today, which is to implement (more or less directly) methods defined in...

Byte-coded methods in the Java Virtual Machine are perfectly suited for their main role today, which is to implement (more or less directly) methods defined in the Java Language, version 1.0.Java classes and methods do not directly implement free-standing chunks of code found in other languages, such as function pointers, closures, delegates, or extension methods. As in the cases of inner classes, they can do a reasonable job of implementing such design patterns. But there...