Hi Tim,
For your first question, I think your example falls into what the spec calls
"funky looking" keys. See the 3rd bullet point example under
http://www.w3.org/TR/xquery-31/#id-lookup:
> funky / <looking @string") is equivalent to .("$funky / <looking @string"),
> an appropriate lookup for a map with rather odd conventions for keys.
In other words, I think you're stuck with the ("@context") approach.
As to your second question, it looks like what you're proposing should work -
but am I reading you as saying you get an error with your proposed approach?
If so, what's the error?
Joe
Sent from my iPad
_____________________________
From: Tim Thompson <timat...@gmail.com>
Sent: Saturday, January 9, 2016 3:11 PM
Subject: [basex-talk] Lookups and arrows
To: BaseX <basex-talk@mailman.uni-konstanz.de>
Hello,
I'm testing some XQuery 3.1 features against a JSON-LD[1] document
and had a few questions. In the JSON-LD format, the "@" symbol has special
semantics in key names, but seems to cause problems with the 3.1 lookup
operator.
For example:
json-doc(" http://lae.princeton.edu/catalog/0bp35.jsonld";)("@context")
works as expected, but
json-doc(" http://lae.princeton.edu/catalog/0bp35.jsonld";)?@context
throws an error: [XPST0003] No specifier after lookup operator: '@'.
Also, when using the "=>" operator, should it be possible to perform a
lookup on the last expression in a chain, if that expression returns a map?
For example:
json-doc(" http://lae.princeton.edu/catalog/0bp35.jsonld";)("@context")
evaluates to " http://iiif.io/api/presentation/2/context.json";
and
json-doc(" http://lae.princeton.edu/catalog/0bp35.jsonld";)("@context") =>
json-doc()
returns another map object. So, how would one achieve this:
json-doc(json-doc("
http://lae.princeton.edu/catalog/0bp35.jsonld";)("@context"))("@context")
using the arrow operator?
Thanks,
Tim
[1] http://www.w3.org/TR/json-ld/
--
Tim A. Thompson
Metadata Librarian (Spanish/Portuguese Specialty)
Princeton University Library
