JavaScriptCore has never allowed octal sequences (anything other than a . or x
after 0) in strict mode, and we haven't had any problems with it.
--Oliver
> On Aug 5, 2014, at 11:13 AM, Allen Wirfs-Brock <al...@wirfs-brock.com> wrote:
>
>
> On Aug 5, 2014, at 8:38 AM, Mathias Bynens wrote:
>
>> On 5 Aug 2014, at 17:19, Mark S. Miller <erig...@google.com> wrote:
>>
>>> On Tue, Aug 5, 2014 at 8:17 AM, Mathias Bynens <math...@qiwi.be> wrote:
>>>
>>>> The literals under discussion (e.g. `08` and `09`) are not octal literals.
>>>
>>> Strict mode should reject these even more vehemently! (Allen, can we have
>>> an early vehement error?)
>
> I think we weren't clear enough in the ES5 spec. The base-line grammar says
> that starting a decimal literal (other than a single '0') with a 'o' is not
> valid syntax. You should expect to get a syntax error for 00, or 07, or 08,
> or0123456789, or 01234567, etc. ES5 Annex B defines an extension that makes
> sequences of digits (excluding '8' or '9') legal syntax. But section 7.8.3
> says that that particular extension is not allowed in strict mode code.
>
> The problem is that there is another extensions (that is not in ES5 Annex B)
> that allows and gives meaning for '0' followed by digit sequences that
> include the digits '8' and/or '9'. I'm pretty sure that when drafting ES5 we
> thought the restriction in 7.8.3 was making making both of these extensions
> illegal in strict mode. Apparently most real world browsers didn't interpret
> things that way which is unfortunate.
>
>>
>> Now I’m confused again. That contradicts what Allen said earlier in this
>> thread:
>>
>> On 5 Aug 2014, at 16:20, Allen Wirfs-Brock <al...@wirfs-brock.com> wrote:
>>
>>> Regarding, leading 0 constants in strict mode. The long term plan is to
>>> eventually make them legal decimal constants.
>>
>> I stand by my earlier suggestion:
>>
>> 1. Accept decimal integer literals with leading `0`, even in strict mode.
>> 2. Interpret the value of such literals as octal in case they consist of
>> octal digits only. (Note: this is already in Annex B – see
>> `LegacyOctalIntegerLiteral`.)
>>
>> Strict mode would accept `08` as it’s a zero-prefixed decimal literal but
>> not `07` since that’s an octal literal.
>>
>> This matches what all browsers already do (except Firefox), and fulfills the
>> long-term plan Allen was talking about.
>
> I think this is more or less the strategy we should follow.
>
> All browsers in all modes apparently interpret leading 0 numbers that contain
> the digits "8" or "9" as decimal literals. We should make that part of the
> base language for ES6.
>
> The ES6 base language should make leading 0 numbers containing only octal
> digits ("1"-"7") syntactically illegal.
>
> Annex B can continue to define the meaning for such leading 0 octal numbers.
> And strict mode still makes that annex B extension illegal
>
> Someday, when strict mode/modules is more dominant we can relax the
> restriction of leaning 0 numbers without "8" or "9" and make all leading 0
> numbers decimal literals in strict mode.
>
> Allen
>
>
>
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