Who came up with this? Let’s put things in context: JavaScript is a dynamic language. It turns out that this characteristics deeply upsets many people, particularly those who prefer to rely on a compiler to check their code for them before running it. It turns out that these guys also have a hard time imagining their objects in memory, what do they look like, what they do, and so on, and for them ECMAScript 4 will bring types, that is, variables declared both with the var keyword and a special type declaration after the variable name. There is an illusion built around statically typed languages. I know it: I’ve already advocated them as the silver bullet that never existed. But I was wrong, and I admit it. Personally I think that dynamic languages are the future.
The problem with statically typed languages is that “collections” or “containers” of things should also be typed, because otherwise you spend a good deal of CPU time boxing and casting instances, because otherwise you might as well “put a cat in a dog collection” as one commenter put in the Ajaxian page above.
I am sorry but, in the case of JavaScript, the evolution of the current draft is becoming ridiculous, even after you throw in all your arguments about performance, IDE support and who knows what else:
[source:javascript]
function reprimand(list:List.< +Employee>) { … }
var writingTeam:List.
ActionScript 3 developers can already enjoy this “syntax sugar”. Ugh! Continue reading