simple shorter function syntax

[Alex Russell]

On Jul 24, 2010, at 12:27 PM, Brendan Eich wrote:

> On Jul 24, 2010, at 11:00 AM, Alex Russell wrote:
> 
>> On Jul 24, 2010, at 9:21 AM, Kevin Curtis wrote:
>> 
>>> Should the proposed shorter form # desugar to function or a const function:
>>> http://wiki.ecmascript.org/doku.php?id=strawman:const_functions
>> 
>> Regular, plain-old function. No funky return semantics (ala some of the closure proposals), no extra qualifiers. If you want 'em, you can pay for 'em. The common problem "#" attempts to address is the huge verbosity of "function", nothing more.
> 
> That's not what the proposal from you and arv says :-/:
> 
> http://wiki.ecmascript.org/doku.php?id=strawman:shorter_function_syntax
> 
> The completion value of the statements in the braced body of a # function is the return value.

I take the point, but again, that's to shorten things up, not to change semantics where you would have otherwise added a "return".

My apologies for being imprecise.

>>> I dislike the verbosity of function - though I can't help feeling #
>>> could be used for other ends.
>>> 
>>> let dict = #{"hello": 4, "world":5}; // it's a hash/dict not an object
>> 
>> So a new dictonary/map type is interesting, but it's unclear that we really need anything like that until/unless we turn off the "delete" operator.
> 
> Why wouldn't you ever delete from a dictionary?

Oh, you would, but if you have a new dictionary type, you can turn of "delete" in regular objects and provide a new method on the dict to handle that internally.

> The real motivator for dictionaries is to avoid Object.prototype pollution of the dict's "in" (not "own") property namespace.

Which sound the like the long way around just providing a form of the iterator that list only the hasOwnProperty items.

>>> let arr = #[4,4,5] // typed array - Numbers only - contiguous memory block?
>> 
>> How about we start with the long form for things that are currently uncommon and shorten them when they become painfully long to use?
> 
> Good in general if you can iterate quickly enough. If we can cut to the chase, even better given the cycle times among browsers and Ecma editions.

...which can go down if we can get the cycle times for browser versions down. We're building a language predicated on browser resource/network behavior constraints and we succeed/fail by browser adoption. Given that browsers are moving faster, I suspect we'll get another shot at shortening obviously-painful and hard-to-use Harmony features sooner rather than later.

Regards

> I see Kevin's point, too: use # for "hashes" and other object initialiser extensions, use something more lambda-looking for function.
> 
> /be

--
Alex Russell
slightlyoff at google.com
slightlyoff at chromium.org
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