JSR 292: Supporting Dynamically Typed Languages on the Java Platform - Early Draft Review | Hacker News Reader

JSR 292: Supporting Dynamically Typed Languages on the Java Platform - Early Draft Review

jcp.org

8 pointsfoemmel4 comments

Strong typing is one of the reasons that I LIKE Java. Especially on large projects it's nice knowing exactly what a variable is, and what data elements and methods are available.

I hope this doesn't lead to people using sloppy typing in Java applications.

The idea is to add native support for dynamic languages (e.g. Ruby, Python, etc) to the JVM, not to make the Java language itself dynamic.

I know. I just worry that people will gravitate toward using more and more dynamic language code in their applications/platforms/frameworks because it's "easier". And then I'll end up needing to use some library that has a truckload of python code in it, that A) isn't strongly typed, and B) I don't understand.

Hopefully it won't be an issue.

I look forward to having dynamic languages improving on the JVM. When I moved from doing all of my work in Java to learning and doing mostly Lisp at work, I learned one of the biggest headaches of coding wasn't a lack of static typing (strong is not the issue), but NullPointerExceptions, which doesn't plague my Lisp code. And for the defmethods where nil's might cause an error for not being handled, NULL is actually a type that I can code for to avoid the problem entirely.

Another thing I realized was how much code, or rather code-supporting files, where already in other languages around Java. There's Ant, ejb-jar, properties, SQL, numerous internal and external XML, Javadoc, annotations, manifest, xslt, jsp, html, css, javascript. Point 1: don't worry about Python, it's a better language than many of those you're already using with Java. Point 2: with Lisp, it can be all Lisp, or you can integrate with other such languages where you need to. I think the reason Java has all of these satellite languages (especially XML) and files is because the language is so weak and inflexible - Lisp is as flexible as XML, but works nicely as a programming language.

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