Re: [Json] Leading and trailing whitespace

Carsten Bormann <cabo@tzi.org> Tue, 11 June 2013 05:15 UTC

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From: Carsten Bormann <cabo@tzi.org>
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Date: Tue, 11 Jun 2013 07:14:25 +0200
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To: Nico Williams <nico@cryptonector.com>
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Cc: Jim Schaad <ietf@augustcellars.com>, Paul Hoffman <paul.hoffman@vpnc.org>, json@ietf.org
Subject: Re: [Json] Leading and trailing whitespace
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On Jun 11, 2013, at 05:42, Nico Williams <nico@cryptonector.com> wrote:

> Do implementations that allow any value type at the top-level allow
> leading and/or trailing whitespace?

Yes.  E.g.,

>> JSON.parse("\r\n \t 27 \r\n \t", quirks_mode: true)
=> 27

(quirks_mode is the flag that switches on the non-coforming acceptance of any "value".)

> *Should* they?

Yes.

(If you are not convinced from first principles: people have argued you can do streaming by adding whitespace, and that required being allowed to add whitespace :-)

So we will have to add a production:

	JSON-value = ws value ws

That didn't seem too hard.

Thanks for pointing this out, Jim.

This production can be in 4627-bis or in the document that defines the application/json-value media type, if we want to go the latter route.

Grüße, Carsten

PS.: Just to show that trailing whitespace is indeed properly parsed:
>> JSON.parse("\r\n \t 27 \r\n \t 28", quirks_mode: true)
JSON::ParserError: 795: unexpected token at '28'