Brendan Eich Explains ECMAScript 3.1 To Developers

VonGuard writes "On April 9, ECMA International produced the final draft for the first major update to JavaScript since 1999. It's called ECMAScript 3.1, but will soon be known as ECMAScript, Fifth Edition. You'll know it as JavaScript, the Next Generation. Mozilla will begin implementing these features after Firefox 3.5, and Microsoft is already showing prototypes behind closed doors. The question, however, is what this will change for JavaScript coders. To get those answers, I tracked down Brendan Eich, Mozilla's CTO and the creator of JavaScript. I transcribed the interview without any editorial since he explains, perfectly, what's changing for programmers. Long story short: Json will be safer, getters and setters will be standard, and strict mode will make things easier to debug."

Comments

Let's get this out of the way now

[Anonymous Coward]

I'm holding out for ECMAScript 3.11 for Workgroups!

Re:OOP?

[bishiraver]

ECMAScript is a prototypal functional programming language. You don't just set members of an object by defining its prototype in an object literal.

You can also, by the power of closures, have private functions, private variables, and protected functions. (ECMAScript is interesting in that public member functions cannot access private variables, but protected functions can. Downside is that protected functions (defining them as this.foo = function() {}; in the constructor) are created new for each instance of the object, unlike the prototype (public) members.

While ECMAScript isn't built to enhance tail recursion, it's actually possible. For example, a continuous passing style fibonacci sequence calculator.

Not quite as readable as haskell or lisp, but still - proves that JavaScript is a true functional programming language.

Sweet!

[coryking]

First, JavaScript is a very nice language indeed. If you've never learned functional programming, JavaScript is a good language to learn in. Why? You can actually do real work while learning! As for the new language spec...

Getters and setters are nice, but I'm not sure they serve a purpose in javascript--javascript is more functional than it is OO and I think people learning the language should change mindsets rather than the langage get bastardized to something it is not. I dunno, somebody can challenge me on this.

Good to see they are thinking about adding a "use strict". You aren't an adult language until you have a way to force variable declaration. Hopefully "use strict" will apply to a module or block, not to the entire project. I want to "strictify" my own JavaScript, but I dont want the browser to choke on some sloppy copy-and-paste deal from AdSense or analytics.

Lastly, JSON. There are a couple "gotchas" with it... namely when you generate JSON using a loosely typed language like Perl and try to feed it into a strongly typed language like C# (i.e. silverlight). Depending on the serializer / deserializer used on the strongly-typed side, you'll run into things.

For example, the deserializer in C# just might choke on this:
"themes": [ // it will puke on this:
        {
                "theme_id": "34", // i am a string!
                "last_mod": "2009-04-09 13:04:27.232-07" // I am a postgresql date, but I'd also barf on ISO8601
        }, // puke free:
        {
                "theme_id": 34, // I am an int!
                "last_mod": new Date(3000, 00, 01, 00, 00, 00) // i am a legit Date()
        }

]

Why? Perl serialized the integers as a string. Depending on the deseralizer, it might choke on those strings if it was expecting a number. YUI would also be pissed off about the date not being a javascript Date()--good luck finding a serializer that produces such a thing! My point? These are some surprise gotchas you have to worry about when dealing with JSON. Not sure who is to "blame"--perl for being loosely typed, the deserializers for being to strict. This would be a problem with XML as well though.