erik.corry at gmail.com
Wed Jun 24 10:59:10 PDT 2009
2009/6/23 Brendan Eich <brendan at mozilla.com>
> On Jun 23, 2009, at 12:18 AM, Christian Plesner Hansen wrote:
> I've been looking around on the web for reasons why decimal arithmetic
> should be added to ES. The most extensive page I could find was
> http://speleotrove.com/decimal/decifaq.html. If anyone know other
> good sources of information about decimal and its inclusion in ES
> please follow up.
> Mike Cowlishaw's pages on decimal have lots of arguments for it:
I'm afraid both these links seem to have broken.
> The most-duplicated JS bug in bugzilla.mozilla.org is
> Here's a typical naive JS user complaining that his computer his broken
> because it can't calculate correct differences:
> "... I typed in:
> … and here is the garbage Apple babbled back at me: 9318.139999999999"
> He blamed Apple. Naive users often blame hardware for software bugs.
> The strongest argument seems to be financial: binary arithmetic is
> approximate in a way that makes it unsuitable for financial
> calculations. I buy this argument in general -- I would definitely
> want my bank to use some form of decimal arithmetic rather than binary
> -- but less so in the context of ES.
> Do you consider that naive user's calculator example to be "financial"? I
> do not.
> The problem is worse for non-experts. The experts can cope.
> Anyway, decimal is not being pushed into JS at this point. At the last
> face-to-face TC39 meeting, we changed direction to explore generalizing
> value type support (including operators and literals if we can) so that
> libraries could add first class number-like types.
> Whether any new value type would be native or self-hosted, and whether it
> would be included in the core standard, are issues we want to defer until
> later, ideally until there are de-facto standards to codify.
> The counter-argument articulated at the meeting by Sam was that it's rare
> for users to download binary extensions to JS for browsers (Flash is the
> only exception, and it's not primarily a JS extension). So users won't get
> decimal unless it is part of the normative core spec, so the usability bug
> reported as Mozilla bug 5856 won't get fixed.
> I think Sam has a point; lack of a standard could be a problem. But
> whatever we do about it, the committee agreed to work on value types first.
> They're on the Harmony agenda.
> es-discuss mailing list
> es-discuss at mozilla.org
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the es-discuss