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[Json] Unpaired surrogates in JSON strings

John Cowan <cowan@mercury.ccil.org> Wed, 05 June 2013 16:22 UTC

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From: John Cowan <cowan@mercury.ccil.org>
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Subject: [Json] Unpaired surrogates in JSON strings
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RFC 4627 Section 1 says:

    A string is a sequence of zero or more Unicode characters.

However, the grammar of strings permits things like "foo\uDC00bar",
which contains an escape sequence that does not correspond to any
Unicode character.  This provides backward compatibility with JavaScript,
where a string is not a sequence of characters but a sequence of UTF-16
code units.

If Section 1 is normative, then there is a contradiction with Section 4,
which says:

    A JSON parser MUST accept all texts that conform to the JSON
    grammar.

In my view, JSONbis processors should be REQUIRED to produce only strings
that conform to Section 1.

-- 
And it was said that ever after, if any                 John Cowan
man looked in that Stone, unless he had a               cowan@ccil.org
great strength of will to turn it to other              http://ccil.org/~cowan
purpose, he saw only two aged hands withering
in flame.   --"The Pyre of Denethor"

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