Re: match specific blank terms

Thank you all. I understand now.

On 24 November 2017 at 15:49, Gregg Kellogg <gregg@greggkellogg.net> wrote:

> On Nov 24, 2017, at 7:21 AM, Anthony Durity <a.durity@umail.ucc.ie> wrote:
>
> One last mail from me for now.
>
> The alternative is that I avoid Array#include? and use something like
> terms.any?{|t| t == n }
>
> Does anyone have any thoughts on the matter?
>
>
> That’s pretty much what you’re left with, but with a large repository,
> could be very expensive. As a general rule, when using a SPARQL endpoint,
> you can use the form Ian suggested using FILTER, such as SELECT ?bn WHERE
> {?bn ?p ?o . FILTER(?bn == _:foo) } UNION {?s ?p2 ?_bn . FILTER(?bn ==
> _:foo) }
>
> When working with an in-memory repository, then terms.any? {|t| t.node? &&
> t.iid == “foo”} is probably reasonable.
>
> Gregg
>
> On 24 November 2017 at 12:05, Anthony Durity <a.durity@umail.ucc.ie>
> wrote:
>
>> Ok, having looked at the code for RDF::Node I guess my question is. Why
>> is #eql? different to #== for RDF::Node ? That gives me the situation where
>> terms.last == n is true but terms.include?(n) gives me false.
>>
>> On 24 November 2017 at 09:14, Ian Dickinson <i.j.dickinson@gmail.com>
>> wrote:
>>
>>> Hi Anthony,
>>> On Thu, Nov 23, 2017 at 10:13 PM, Anthony Durity <a.durity@umail.ucc.ie>
>>> wrote:
>>> > I was working under the impression that 'local scope' meant local to
>>> the
>>> > repo.
>>> >
>>> > Given that I have:
>>> > [
>>> > #<RDF::URI:0x2ac3bff25014 URI:https://dh.ucc.ie/entity/α54>,
>>> > #<RDF::URI:0x2ac3be8bc444 URI:http://www.wikidata.org/prop/direct/P31
>>> >,
>>> > #<RDF::URI:0x2ac3bff2c5d0 URI:http://www.wikidata.org/entity/Q187685>,
>>> > #<RDF::URI:0x2ac3bff32b60 URI:https://dh.ucc.ie/entity/α55>,
>>> > #<RDF::URI:0x2ac3bff3f9f0 URI:https://dh.ucc.ie/entity/α56>,
>>> > #<RDF::URI:0x2ac3be892504 URI:https://dh.ucc.ie/entity/α57>,
>>> > #<RDF::Node:0x2ac3c025570c(_:g47253167721100)>,
>>> > #<RDF::Node:0x2ac3bf67d7b8(_:59)>,
>>> > #<RDF::Node:0x2ac3c0265d50(_:α60)>
>>> > ]
>>> > what's the best way to match the blank node 'α60' ? I tried “intern”
>>> just
>>> > there and it didn't work :/
>>>
>>> I think it would be easier to offer advice if you could back up a bit
>>> and say what you're
>>> trying to achieve? As Gregg said, bNodes can be funny things, so the
>>> 'best
>>> way' to handle them tends to be a bit "well, it depends ..."!
>>>
>>> Ian
>>>
>>
>>
>
>