Java
the OpenJDK group at Oracle is growing
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 repository or OpenJDK mailing list. Here is a typical job description from the current crop of requisitions: The Java...
Tuesday, March 27, 2012 | Java | Read More
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 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...
Friday, December 2, 2011 | Java | Read More
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. 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 invo...
Saturday, March 28, 2009 | Java | Read More
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 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...
Wednesday, August 1, 2007 | Java | Read More
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-languages I 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...
Tuesday, June 5, 2007 | Java | Read More
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 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...