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Re: Minor Syntax issues

From: Alberto Reggiori <alberto@asemantics.com>
Date: Tue, 15 Feb 2005 16:51:32 +0100
Message-Id: <9b092ba45db62864f765b3a465345009@asemantics.com>
Cc: "'RDF Data Access Working Group'" <public-rdf-dawg@w3.org>
To: andy.seaborne@hp.com


Andy,

for the record, here are our answers/input to your syntax issues

On Feb 11, 2005, at 10:02 PM, Seaborne, Andy wrote:

>
> This is about tuning the current syntax, post-WD2 publication, not 
> redesigning the whole thing.
>
> 1/ Bound
>
> This is special because it tests the variable, not the value.  It's 
> the only
> case where this happens.
>
> The suggestion (PatH) was to make this different.  In other 
> programming languages, there is just a plain function like many other 
> library functions.  It returns a value (a boolean) like any other 
> function.
>
> Options:
> 1a/ BOUND(?x)   -- as the current grammar

+1 for current form in the grammar

> 1b/ BOUND[?x]   --  different grouping
>
> Anything with a colon in it will look like a qname.
>
> BOUND ?x is dangerous as it does not express the tight binding nature 
> of
> this operator: "BOUND ?x && ?y" is strange.
>
> I prefer "BOUND(?x)" -- leave as is.
> BOUND[] as a one-off is over doing it.
>
> 2/ AND
>
> AND is a special keyword that starts constraints (SUCH THAT would be 
> better
> but its two words).  Currently in the grammar it is required because 
> ?x-?y is unclear : can be "?x binary minus ?y" or two expressions "?x" 
> then "unary minus ?y"

please keep AND for this round still

>
> Proposal: use [] to mark constraints (see below).
>
> 3/ OPTIONALS
>
> There are two syntactic forms "OPTIONAL" and "[]"
>
> Proposal: just the OPTIONAL form, freeing up [] for constraints.

ok to drop [] and use only OPTIONAL keyword

>
> 4/ Functions , casting and specials.
>     &ex:foo() , xsd:byte(23) , isBlank(?x)

we are neutral about this one

> 5/ LOAD => WITH
>
> The word "LOAD" suggests, to some people, a permanent change to the 
> database which is a wrong implication.  DaveB suggested changing the 
> word to "WITH".  I have done this change (rq23 and the tests).

ok for WITH change

>
> 6/ Clause order
>
> The current order is:
>
> BASE
> PREFIX
> SELECT
> WITH
> FROM
> WHERE
> LIMIT
>
> which is a mixed style.  It would make sense to have WITH and FROM 
> before SELECT (declarations first) and have LIMIT before WHERE 
> (modifier to SELECT).  It has confused some RDQL users that FROM comes 
> after SELECT.

ok for given order - but please add few lines explaining BASE keyword 
in the prolog, still only mentioned into grammar/bnf in ver. 1.207


Yours

Alberto

-
Alberto Reggiori, @Semantics S.R.L.
www.asemantics.com
Received on Tuesday, 15 February 2005 15:51:37 GMT

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