Tuesday, November 25, 2008

NetBeans Screenshot of the Week #37: JavaScript 1.7 Support

WARNING: This blog entry was imported from my old blog on blogs.sun.com (which used different blogging software), so formatting and links may not be correct.

I just checked in support for JavaScript 1.7. This means that NetBeans will no longer give you syntax errors if you try to use the new language. Here are some screenshots. First, let's open a file using JavaScript 1.7 constructs:

Obviously the file is using yield which is not recognized as a keyword, and in particular, this is just a syntax error - the parser was expecting a semicolon. But there's a little lightbulb... let's see what it says (type Alt-Enter or click on the lightbulb):

Let's select the option to change the active language to 1.7. I could also open the JavaScript options dialog directly and set it to 1.7 as shown here:

After applying the language change, the editor immediately re-lexes and reparses the file according to the new language. The errors are gone, and yield is now a proper keyword:

Similarly, the let keyword can be used, as well as destructuring assignments, generators and iterators, etc. (See New In JavaScript 1.7 for more information).

If you place the caret on function definitions, it will highlight all exit points, and this includes yields now.

This work isn't done; I'd like it to be smarter about generators, and there may be some issues with scope handling. But at least the editor doesn't get in your way with false error messages now - you can start writing JavaScript 1.7 clean code. (This is with NetBeans 7.0 dev).

In related news, I just heard from Tom Enebo that a lot of Ruby 1.9 language features are now supported by the JRuby trunk parser, so hopefully we can soon start fully supporting Ruby 1.9 features in NetBeans as well.

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