Re: [Json] JSON: remove gap between Ecma-404 and IETF draft

[Allen Wirfs-Brock <[e-mail]>]

On Nov 13, 2013, at 3:51 PM, Joe Hildebrand (jhildebr) wrote:

> On 11/13/13 3:47 PM, "John Cowan" <[e-mail]> wrote:
> 
>> It's not clear that 404 disallows it, since 404 is defined in terms of
>> characters, and a BOM is not a character but an out-of-band signal.

However, for example, a conforming implementation of the ECMAScript JSON.parse function would reject any string passed to it that starts with a U+FFEF code point because the unquoted occurrence of that code point does not conform to the ECMA-252, 5th Edition or Ecma-404 JSON grammar.

In order to be successfully processed, that code point would have to be stripped from the string prior to calling JSON.parse.

Allen

> 
> Agree.  However, that signal would be a part of the 4627bis octet stream,
> so a little interop guidance would likely be useful.  Something like:
> 
> "Some producers of JSON produce JSON-text that starts with a redundant
> U+FEFF (ZERO WIDTH NO-BREAK SPACE, previously known as BYTE ORDER MARK)
> with the ostensible purpose of signaling the encoding of the text to
> follow.  Since JSON has other mechanisms to determine encoding, this is
> not required.  Receiving applications MAY safely ignore this initial
> character without generating an error.  Implementations that do not send
> U+FEFF are interoperable in the sense that all software implementations
> which receive the un-prefixed text will not generate parse errors."
> 

Isn't it an interooperbility issue that many receiving applications do not ignore it.

Allen