Map literal

Alexander Jones alex at
Wed Oct 28 01:21:24 UTC 2015

True, but easy to mess up and only be treated to a runtime error. Three
nested brackets at the start and end could definitely be better, and
this just encourages people to use POJSOs instead. Also not a very uniform
interface if you look at how to construct a Map, Set or Immutable.List at
present, though admittedly constructor call for the ES6 types would be a
partial improvement.

On Wednesday, 28 October 2015, Tab Atkins Jr. <jackalmage at> wrote:

> On Wed, Oct 28, 2015 at 8:36 AM, Alexander Jones <alex at
> <javascript:;>> wrote:
> > I agree this is pretty important. Using actual maps really frees up a
> lot of
> > complexity, but the syntax is cumbersome to say the least.
> >
> > Whatever the decided syntax, bare words as string keys is a really bad
> idea
> > IMO. The key syntax should be parsed as an expression, like the values
> are,
> > and like they are in basically every other language.
> >
> > Another outstanding issue is that we might want the syntax for
> > `Immutable.Map`, or `WeakMap`, or `MapTwoPointOh` that improves
> deficiency
> > $x, $y and $z. I'd say introducing a special syntax for `Map` right now
> is
> > not ideal.
> Currently, the "extensible literal syntax" for this isn't that bad:
> const bar = 43;
> const map = Immutable.Map([["foo", 42], [bar, 44]]);
> It's a little more verbose because the entries have to be surrounded
> by [], but hey.
> ~TJ
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