ECMAScript Harmony

Garrett Smith dhtmlkitchen at
Fri Aug 15 13:40:40 PDT 2008

On Wed, Aug 13, 2008 at 2:26 PM, Brendan Eich <brendan at> wrote:
> It's no secret that the JavaScript standards body, Ecma's Technical
> Committee 39, has been split for over a year, with some members
> favoring ES4, a major fourth edition to ECMA-262, and others
> advocating ES3.1 based on the existing ECMA-262 Edition 3 (ES3)
> specification. Now, I'm happy to report, the split is over.

That is good to know.

> A split committee is good for no one and nothing,

It led to contrasting ideas.

> There remain challenges, in particular getting off of the untestable
> and increasingly unwieldy ES1-3.x spec formalism.

Unit tests:
 * help developer understanding
 * provide examples for discussion
 * provide conformance suite for implementors
 * define boundaries on what is and what is not supported*

The tests could use a custom test runner or use an existing one. It
would be useful if the testrunner could be run in a browser.

It would be helpful to have code comments in the tests, indicating
exactly which rules of the spec are being tested, so that the reader
can quickly go to that section of the spec (spec in HTML).

Real code examples in the spec would be useful, too. I can easily see
a bookmarklet used to capture and execute the example selection of the

* defining "not supported" could be as simple as having an assertion
test that should be ignored, and should be marked ignore, along with a
comment as to why the test is ignored (use of Host object, et c).
Ignored tests can be a useful form of documentation.

> As Waldemar Horwat (Google) said on the final day, the meeting was
> seminal,

I like it.


> /be

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