`ExponentPart` after `HexIntegerLiteral`

The spec grammar for `HexIntegerLiteral` is as follows:
http://es5.github.com/x7.html#x7.8.3

HexIntegerLiteral ::
    0x HexDigit
    0X HexDigit
    HexIntegerLiteral HexDigit

HexDigit :: one of
    0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F

Note that no `ExponentPart` seems to be allowed here.

However, a lot of engines seem to support exponents after hex integer literals:

    255; // 255
    0xFF; // 255
    255e2; // 25500
    0xFFe2; // 65506

I couldn’t find this in the spec though. Is this defined anywhere? Is
this expected behavior or not?

Hello,

0xFFe2 is valid HexIntegerLiteral, because 'e' and '2' is one of the hex
digit.
So I think it is OK.

0xFFe2 // 65506
0xFFe3 // 65507

Thanks.

On Sat, Feb 25, 2012 at 10:40 PM, Mathias Bynens <mathias at qiwi.be> wrote:

> The spec grammar for `HexIntegerLiteral` is as follows:
> http://es5.github.com/x7.html#x7.8.3
>
> HexIntegerLiteral ::
>    0x HexDigit
>    0X HexDigit
>    HexIntegerLiteral HexDigit
>
> HexDigit :: one of
>    0 1 2 3 4 5 6 7 8 9 a b c d e f A B C D E F
>
> Note that no `ExponentPart` seems to be allowed here.
>
> However, a lot of engines seem to support exponents after hex integer
> literals:
>
>    255; // 255
>    0xFF; // 255
>    255e2; // 25500
>    0xFFe2; // 65506
>
> I couldn’t find this in the spec though. Is this defined anywhere? Is
> this expected behavior or not?
> _______________________________________________
> es-discuss mailing list
> es-discuss at mozilla.org
> https://mail.mozilla.org/listinfo/es-discuss
>
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Oh my, that was embarrassing. Haven’t trolled myself like that in a long time.

Thanks Yusuke!