[sc34wg3] Fwd: Re: TMQL: Grammar broken II

Lars Heuer heuer at semagia.com
Mon Feb 23 14:58:35 EST 2009


Forgot to include the list, sorry.



This is a forwarded message

From: Lars Heuer <heuer at semagia.com>
To: Robert Barta <rho at devc.at>
Date: Monday, February 23, 2009 8:57:55 PM
Subject: [sc34wg3] TMQL: Grammar broken II

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Hi Robert,

> On Thu, Dec 04, 2008 at 01:42:54PM +0100, Lars Heuer wrote:
>> Found another bug in the grammar; according to "4.7 Composite Content"
>> this is a valid TMQL expression:
>> 
>>      // person -- // evildoer
>> 
>> 
>> But it is impossible to accept the expression according to the
>> grammar. If the entry point is "path-expression", there is no way to
>> accept the "--" and the other path expression.

> That's correct. But that is the same as saying

>   If the entry point is "constant" then 2 + 3 is
>   not parseable.

> For the above I have

>    content -> content   '--'  content              [23]
[...]
>            -> // person -- // evildoer

> Please double-check.

Yes, that works. My e-mail wasn't very clear, sorry. Here another try.
The entry point for all queries is

    [46]    query-expression

and [46] is defined as (abbreviated):

    select-expression | flwr-expression | path-expression

So, the parser sees "//person" and enters the "path-expression" rule
and there is no way to accept the "--" since once you're in
"path-expression" you cannot reach the content-rule [23].

Do I miss something?

Best regards,
Lars
-- 
Semagia 
<http://www.semagia.com>

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