Syntax Questions

[rwaldron]

1. What does this mean:

a 
{}

2. What does this mean:

a()
{}

[leobalter]

a NoLineTerminator is certainly required to avoid breaking a matching LHSExpressoin + a Block

[samuelgoto]

Right, this came up while running this by @waldemarhorwat. In the current formulation, as @leobalter said, these two things would mean different things.

a 
{}

Are two statements, one with a as an identifier and the second as an object literal {}.

On (2), the same thinking applies:

a()
{}

It means a method call a() and an object literal {}.

Does that make sense?

[leobalter]

Are two statements, one with a as an identifier and the second as an object literal {}.

it's not an object literal, it's a Block. ASI needs to prevail as both are valid code already.

var a = 42;
a
{}

The completion value should be 42 (getting a)

[samuelgoto]

Ah, fair, yes, a block. Still, point being that this is NOT equivalent to a(function {}).

Makes sense?

On Thu, Nov 9, 2017 at 11:35 AM, Leo Balter [email protected] wrote:

Are two statements, one with a as an identifier and the second as an object literal {}.

it's not an object literal, it's a Block https://tc39.github.io/ecma262/#prod-Block. ASI needs to prevail as both are valid code already.

var a = 42; a {}

The completion value should be 42 (getting a)

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[rwaldron]

@samuelgoto

Does that make sense?

Mostly, but @leobalter already pointed out the important corrections.

Still, point being that this is NOT equivalent to a(function {}).

That's what I was hoping to verify. This issue can be closed once a valid grammar exists which satisfies the requirement, ideally @leobalter's recommendation.

[samuelgoto]

a NoLineTerminator is certainly required to avoid breaking a matching LHSExpressoin + a Block

@leobalter 's recommendation works for me. I'm going to keep this open just to make sure we don't forget this when writing a more specific spec (the text right now is very informal).

good catch, thanks!