On Thu, May 31, 2012 at 5:40 PM, Mark S. Miller <[email protected]> wrote:
snip
>
> If the predicate means what I think it should mean, I can offer some
> examples of when I would do this. If the predicate means anything else
> that's been advocated on this thread, such as "fat arrow or bound", then I
> have no idea why anyone would ever write code as above. Can anyone offer a
> concrete example? If not, then I suggest that these other proposed meanings
> are simply not useful.
>
>
Mark,
I'm going to take a stab at this, because I think I have a good
understanding of what the JSFixed group is concerned about...
// Imaginary DOM library
DOM = {};
// This function accepts a function as it's second argument,
// what happens when its a bound function? I'd like write the
// API in a way that is friendly to both types of function
DOM.each = function( elems, callbackFn ) {
var bound;
// I made this up, but it makes sense because fat arrows don't
// have a prototype, so Function.prototype.isBound() is out
//
if ( !Function.isBound(callbackFn) ) {
// When not explicitly bound,
// DOM.each sets |this| to the object being iterated
bound = callbackFn.bind( elems );
}
[].forEach.call( elems, callbackFn );
}
let nodes = document.querySelectorAll(".theclass");
DOM.each( nodes, function( index ) {
// the node is at: this[ index ]
});
function ListOfNodes( selector ) {
let nodes = document.querySelectorAll( selector );
// I don't want to return a NodeList, I'm
// making my own API - WOO!
DOM.each( nodes, index => {
// |this| is the constructed instance
this[ index ] = nodes[ index ];
});
this.length = nodes.length;
}
// I might make my own API for
// manipulating my ListOfNodes
// ListOfNodes.prototype.foo...
var list = new ListOfNodes(".class");
list;
> [ div.class, div.class (use imagination) ]
Hopefully this helps!
Rick
_______________________________________________
es-discuss mailing list
[email protected]
https://mail.mozilla.org/listinfo/es-discuss
