Dave, if nesting were out of the question and monocle-mustache operator always
looked like an object literal as they currently exist, would it still be as
vile? With that form, I'm a big fan.
/Rick
On Nov 11, 2011, at 3:13 PM, David Herman <dher...@mozilla.com> wrote:
> On Nov 11, 2011, at 10:50 AM, Erik Arvidsson wrote:
>
>> We've all looked at jQuery code and envied the conciseness of its chaining
>> APIs. Most of us also looked at it and thought; Yuk, making everything a
>> method of jQuery and always return the jQuery object is ugly.
>
> Beauty is in the eye of the beholder... jQuery made combinator libraries
> cool, and for that this functional programmer is permanently indebted to
> jresig.
>
> But really, there's a world of difference between the chaining done by
> libraries like jQuery and the chaining you get from this operator. The former
> is pure, the latter is a mutation. The .{ syntax obscures this fact, and I
> find that inexcusable.
>
> I'm not saying mutation is bad -- JS is no pure functional language, nor
> should it be. But creating an assignment operator that doesn't suggest
> syntactically that it's an assignment, and worse, advertising it as a
> "chaining operator" as if it were the same thing as what jQuery does, makes
> the same mistake of masking mutation that so many imperative programming
> languages make. Languages should be up front when they use mutation and not
> try to hide it or confuse programmers into not knowing when they're doing it.
>
> Just for contrast, here's what your example might look like with a more
> explicit assignment syntax:
>
> document.querySelector('#my-element') .= {
> style .= {
> 'color': 'red',
> 'padding': '5px'
> },
> textContent: 'Hello'
> };
>
> But that nested thingy smells awfully funny to me. This reminds me of
> excessive uses of "point-free style" in Haskell, where people do back-flips
> just to avoid creating variable names for intermediate results. Variables
> aren't evil! Sometimes it's just cleaner to use a local variable:
>
> let elt = document.querySelector('#my-element');
> elt.style .= {
> 'color': 'red',
> 'padding': '5px'
> };
> elt.textContent = 'Hello';
>
> Worse, notice that you have provided *only* an ability to do deep mutation
> here, and no way to do a functional update (such as a copy with the specified
> changes, or a prototype extension with the changes) on nested structure. My
> spidey-sense was already tingling with monocle-mustache, but this nesting is
> another turn for the worse.
>
> Dave
>
> _______________________________________________
> es-discuss mailing list
> es-discuss@mozilla.org
> https://mail.mozilla.org/listinfo/es-discuss
_______________________________________________
es-discuss mailing list
es-discuss@mozilla.org
https://mail.mozilla.org/listinfo/es-discuss
