Quibbling Over Semicolons

re: Quibbling Over Semicolons

David Cumps — Mon, 02 Feb 2004 22:04:00 GMT

Completely agree
don't be lazy :)

re: Quibbling Over Semicolons

Louis Parks — Mon, 02 Feb 2004 22:25:00 GMT

What was the reasoning behind allowing devs to not use semis in the first place?

re: Quibbling Over Semicolons

mike — Tue, 03 Feb 2004 06:50:00 GMT

Do JScript and JavaScript (ECMAScript, perhaps) differ in this at all?

re: Quibbling Over Semicolons

Eric Lippert — Tue, 03 Feb 2004 08:08:00 GMT

The ECMA spec mandates auto semi insertion, and to my knowledge, JScript and JavaScript both implement it consistently and according to the spec.

re: Quibbling Over Semicolons

Dan Shappir — Tue, 03 Feb 2004 08:45:00 GMT

Here is another example of an ambiguity stemming from this "feature" (and also from the overloaded meaning of the curly brackets):

{ foo: bar() }

Is this an anonymous object, with a single member foo equal to the value returned by bar()? Or maybe this is a code block with a labeled call to bar()? How should JScript (or ECMAScript) behave if it encounters a file with just this text?

I would have much preferred mandatory semi-colons to such ambiguities. Indeed, I would have been in favor of a mandatory use of var to declare variables (even members). These are two examples where trying to make something simpler ends up making it more complex.

Dan (a reader)

re: Quibbling Over Semicolons

Eric Lippert — Tue, 03 Feb 2004 19:08:00 GMT

> How should ECMAScript behave if it encounters a file with just this text?

I see what you're getting at, but actually, this has little to do with auto semi insertion. Basically you're asking should the auto semi inserter do this

{ foo : bar() }; // object literal

or this

{ foo : bar(); } // labeled statement in a block

?

But in ECMAScript the former isn't even grammatical, so the auto semi inserter will never produce it! The parser never even considers that it might be an object literal.

This is not ambiguous because it is simply not grammatical to have a statement consisting of a single expression that begins with a left curly. See section 12.4 of ECMA 262 Revision 3 for the details.

re: When Are You Required To Set Objects To Nothing?

Fabulous Adventures In Coding — Thu, 29 Apr 2004 00:02:00 GMT

The trouble with dynamic languages

C# Nuggets — Mon, 22 Jan 2007 23:44:15 GMT

Javascript is a dynamic language . And that's a problem. On the one hand it allows you virtually

re: Quibbling Over Semicolons

Aaron Moore — Thu, 25 Sep 2008 23:36:00 GMT

Python seems to get along fine without them.