On Sep 12, 2011, at 12:51 AM, Peter van der Zee wrote:
> On Mon, Sep 12, 2011 at 1:04 AM, Brendan Eich <[email protected]> wrote:
>> Type Inference can do a lot. See http://doctorjs.org/.
>>
>> We do not want people adding guards all over their code, IMHO. Anyway, we
>> don't know have guards ES6.
>
> While true, I've found that you can't really overcome the dynamic
> property access unless you can somehow infer that you're operating on
> an array of some fixed type or something like that.
Have you tried pasting code into DoctorJS? It infers monomorphic array types,
parameter types, return types. It's a global analysis.
For example, on SunSpider's crypto-aes.js, DoctorJS figures out that
13: Cipher : function(Array[number], Array[Array[number]]) → Array[number]
given
function Cipher(input, w) { // main Cipher function [§5.1]
...
}
Neat, eh?
Yes, eval and other dynamic code loading facilities require re-analysis. So a
tool will have to use hybrid or JIT techniques. Still doable.
> And function calls
> and result types are actually far more difficult (though not
> completely impossible)
The difficulty is a challenge to the IDE implementor, not to all JS hackers to
annotate their function signatures.
With Flash and AS3, developers over-rotated and annotated everything. Of course
AS3 lacks inference of even a local or inside-function-only kind. But really,
the IDE developers can take one for the team, IMHO.
/be
> to do in es than in a strongly typed language.
> Although I don't really see any clear way of getting around this,
> without some kind of annotation (be it in the language or in
> comments).
>
> - peter
_______________________________________________
es-discuss mailing list
[email protected]
https://mail.mozilla.org/listinfo/es-discuss
