Suggestions for Java Generics Semantics in Java Version 7.0 _ Resurrected (original) (raw)

Ismael Juma mlists at juma.me.uk
Thu Jun 18 02:13:41 PDT 2009

On Thu, 2009-06-18 at 11:06 +0200, Florian Weimer wrote:

Obviously, this heavily constrains the solution space. In the end, Java 5 bytecode could not run on pre-Java 5 VMs, so this requirement was somewhat pointless, wasn't it?

Neal answered this question in a blog entry a few years ago:

http://gafter.blogspot.com/2004/09/puzzling-through-erasure-answer.html

There are obvious disagreements on how important and/or feasible reified generics on the JVM are. For example, a blog entry from Peter Ahé (then working on javac at Sun) paints a different picture than what has been said in this thread:

"The problem is the lack of reification. In other words, the lack of runtime type-information about generic types (at runtime, you cannot tell an ArrayList from a ArrayList). We need to do something about that. It is indeed time to erase erasure!

In the next weeks I'll explain what it buys us and how we can accomplish it."[1]

Unfortunately, Peter soon left to work on Newspeak and we never got to see what his proposed solution was. :)

Best, Ismael

[1] http://blogs.sun.com/ahe/entry/reification

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