On May 29, 2012, at 9:33 AM, Tab Atkins Jr. wrote:
> Same thoughts here. Regular devs (like me!) only see
> [[DefineOwnProperty]] when creating a literal, and then there's no
> observable distinction between these two in normal circumstances:
Bingo. The different between [[DefineOwnProperty]] and [[Put]] is subtle and
rarely encountered when dealing with a new object.
The distinction between the two operations is a corner case of the language,
and [[Put]] is the common case.
> I don't think it's worth optimizing for the [[DefineOwnProperty]]
> case. We should just use the standard "foo:bar" syntax, and have it
> invoke [[Put]] behavior.
I agree we should only be considering syntax for [[Put]] -- syntactic sugar
should be to support common patterns, not to invent patterns that don't fit
smoothly within the rest of the language.
However, I really, really oppose reusing syntax that's used for declarative
data construction (i.e., literals) to notate *update* operations. We should not
use the object literal notation for [[Put]]. We should use assignment syntax,
which corresponds to doing assignment on an object.
This was the motivation between my blog post a while back on a different syntax
for mustache:
http://blog.mozilla.org/dherman/2011/12/01/now-thats-a-nice-stache/
tl;dr: instead of an object literal, the RHS of mustache should have a syntax
that corresponds more closely to that of blocks. It allows assignments and
method calls.
array.{
pop();
pop();
pop();
};
path.{
moveTo(10, 10);
stroke("red");
fill("blue");
ellipse(50, 50);
};
this.{
foo = 17;
bar = "hello";
baz = true;
};
(I'll eventually write up a new strawman for it, but I'm working on the new
wiki right now which I consider higher priority.)
Dave
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