Re: [apps-discuss] Question about URI template and expansion of an empty list

"Murray S. Kucherawy" <superuser@gmail.com> Mon, 08 April 2013 13:53 UTC

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Date: Mon, 8 Apr 2013 06:53:49 -0700
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From: "Murray S. Kucherawy" <superuser@gmail.com>
To: James M Snell <jasnell@gmail.com>
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Cc: IETF Apps Discuss <apps-discuss@ietf.org>
Subject: Re: [apps-discuss] Question about URI template and expansion of an empty list
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empty_keys (defined in 3.2) is an empty associative array, not an empty
list.  So we have:

- an undefined value produces "X"
- a defined-but-empty string produces "X."
- a defined-but-empty associative array produces "X"

It's not clear to me that there's a pattern here yielding an obvious answer
for which of the two a defined-but-empty list should produce.


On Mon, Apr 8, 2013 at 6:37 AM, James M Snell <jasnell@gmail.com> wrote:

> Am I missing something subtle about the question? The examples in Section
> 3.2.5 show "X{.empty_keys}" where empty keys = [], expands to "X". Given
> that the list is empty, there's nothing to expand it into.
>  On Apr 8, 2013 5:54 AM, "Francis Galiegue" <fgaliegue@gmail.com> wrote:
>
>> On Mon, Apr 8, 2013 at 8:55 AM, Murray S. Kucherawy <superuser@gmail.com>
>> wrote:
>> > I'm inclined to think it's "X." for the same reason "X{.empty}" is "X.",
>> > which is to say that an empty list, like an empty string, isn't
>> undefined,
>> > but there is indeed nothing to expand.
>> >
>> > Either way, there may be grounds for an erratum here.  The RFC does talk
>> > about handling empty strings, but not empty lists.  The closest is
>> Section
>> > 3.2.1 which talks about "expansion of a defined, non-empty value",
>> meaning
>> > defined, empty values aren't explicitly covered in the prose as far as
>> I can
>> > see.
>> >
>>
>> Similarly, it doesn't talk about extending empty maps.
>>
>> --
>> Francis Galiegue, fgaliegue@gmail.com
>> JSON Schema in Java: http://json-schema-validator.herokuapp.com
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>