Inline.
Summary : it didn't consume the whole input, only up to the end of the
legal part.
On 05/04/2022 12:43, Lorenz Buehmann wrote:
Hi Barry,
Did you try SPARQL1.1 parser instead? Afaik, ARQ was always beyond
SPARQL 1.1 or better said, already before SPARQL 1.1 with some extensions.
Indeed, Andy will correct me soon :D
The grammar files for JavaCC are here:
https://github.com/apache/jena/tree/main/jena-arq/Grammar
You can check arq.jj and sparql_11.jj
Or just wait for Andy's response ...
Cheers,
Lorenz
On 05.04.22 13:21, Nouwt, B. (Barry) wrote:
Hi everyone,
We are using ARQ's SPARQL parser to parse graph patterns and noticed
that it allows dashes in variable names if these variables occur as
the *object* location of a triple pattern. If the variable names at
the *subject* location of a triple pattern contains dashes, it fails
with a ParseException. As far as we could tell the SPARQL
specification does not allow dashes in variable names at all
(https://www.w3.org/TR/sparql11-query/#rVARNAME). The pattern1 and
pattern2 below should both fail, but the first one does not fail and
the second does fail.
String pattern1 = "<test> https://www.tno.nl/example/b ?community-ID .";
ARQParser parser1 = new ARQParser(new StringReader(pattern1));
parser1.GroupGraphPatternSub();
Calling into the middle of the parse doesn't work so easily.
It has parsed up to the end of legal triple pattern.
"<test> https://www.tno.nl/example/b ?community"
when it sees the "-" the variable name has ended and (because the "." is
not required) it is a legal GroupGraphPatternSub
The "-ID ." is left in the token input stream.
You have to test whether end-of-input has been reached.
try
qparse 'SELECT * { <test> <p> ?o-1 }'
Parse error because "-1", the next token (tokenizing is done ahead of
where the parser grammar is the 1 in LL(1)) is not legal.
This is illegal because there is check for end of input:
qparse 'SELECT * { <test> <p> ?o } XXX'
The top level entry point is
void QueryUnit(): { }
{
ByteOrderMark()
Query()
<EOF>
}
so the parser must see <EOF> to be valid and exit without error.
Andy
String pattern2 = "?community-ID https://www.tno.nl/example/b <test> .";
ARQParser parser2 = new ARQParser(new StringReader(pattern2));
parser2.GroupGraphPatternSub();
Is this a bug?
Best regards,
Barry
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