On Nov 13, 2013, at 3:51 PM, Joe Hildebrand (jhildebr) wrote:
On 11/13/13 3:47 PM, "John Cowan" <cowan(_at_)mercury(_dot_)ccil(_dot_)org>
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