Function declarations with lexical `this`?

[David Bruant]

Le 25/06/2013 02:36, Dmitry Soshnikov a écrit :
> On Mon, Jun 24, 2013 at 5:00 PM, Mark S. Miller <erights at google.com 
> <mailto:erights at google.com>> wrote:
>
>     On Mon, Jun 24, 2013 at 4:46 PM, Axel Rauschmayer
>     <axel at rauschma.de <mailto:axel at rauschma.de>> wrote:
>
>         Sorry for bringing this point up, again. It is a minor point,
>         but details matter if ECMAScript 6 is supposed to feel consistent.
>
>         In general, I like how ECMAScript 6 has evolved functions.
>         Before, functions played three roles:
>
>         1. Constructor
>         2. Method
>         3. Non-method function (where you want lexical `this`)
>
>         In ES6, we have classes for #1 and method definitions for #2
>         (in both object literals and class literals). Furthermore,
>         arrow functions replace function expressions and have lexical
>         `this`. What is missing is a function declaration with lexical
>         `this`.
>
>         What's the best way to solve this and to eliminate the pitfall
>         of dynamic `this` (at least for beginners)? Tell people to
>         const-bind arrow functions?
>
>
>     IMO, yes.
>
>         We'd lose hoisting, though.
>
>
>     yes. I don't think this will actually be a problem in practice.
>
>         I also wouldn't want to lose the symmetry function
>         declaration/generator declaration and method
>         definition/generator method definition.
>
>
>     I do sometimes wish there was a natural place to put a "*" on an
>     arrow function, and sometimes I don't wish it. In any case, it's
>     not gonna happen in ES6.
>
>
>         IMO, we need a consistent story for ES6 in this area.
>
>
>     const foo = (a,b) => a+b;
>
>
> For simple procedures-like function still
>
> function doAction() {
>   ...
> }
>
> looks more familiar for programmers than
>
> const doAction = () => {}
You'd be surprised. I've read lots of files from different people where 
I was left wondering "why did he/she choose 'var x = function(){...}' 
over 'function x(){}'". In the end, there was no good reason.

David
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