On Fri, 3 Oct 2008, Timothy S. Nelson wrote:

On Fri, 3 Oct 2008, Timothy S. Nelson wrote:

On Thu, 2 Oct 2008, Timothy S. Nelson wrote:

Now that Perl6 is in the mix, though, I think that the best way to do it is to make roles that model eg. Nodes, Plexes (Documents), Elements, and the like, and then have operators on them do all the work (like my idea of using a slash for a combined feed and call code operator). I could be wrong, but it seems to me that we could get something that's somewhat like XPath this way, without having to worry about defining an XPath grammar or anything.

I'm talking to myself here :). The guys on IRC convinced me that the way to go might be something like a grammar, but that does trees and tree transformations instead of a text input stream. See the IRC log for details :).

Talking to myself again. I'm not as convinced as I was. I'll write up a long post about that if necessary, but want to get something else figured out first. First, a paste from the IRC log:

<TimToady> note to treematching folks: it is envisaged that signatures in a
        rule will match nodes in a tree

My question is, how is this expected to work? Can someone give an example?

I'm assuming that this relates to Jon Lang's comment about using rules to match non-strings.

I'm starting to see how *matching* would work now. But how would it be if I wanted to search a tree for all nodes whose "readonly" attribute were true, and return an array of those nodes? Hmm. Or something like the following XPath...

        /html/body//p/[EMAIL PROTECTED] = "#SampleName"]

(my XPath isn't that great, but I'm assuming this will find all a tags in the html body that are the direct descendant of a paragraph, and have their @name attribute set to "#SampleName"). My guess is something like this:

$htmlobject = HTML->new();

        ==> grep { /html/ } ==> map { .children() }
        ==> grep { /body/ } ==> map { .children() }
        ==> recursivegrep { /p/ } ==> map { .children() }
        ==> grep { /a/ and .name eq "#Samplename" } ==> $anchors

I'm guessing that might do it (although the tree role and recursivegrep would also require some work). But the syntax is dreadful :). You can see why I was talking about having a feed operator that did a grep and got children as well as doing the feed. But no doubt I'm missing something here. And I'm still thinking like a Perl5 programmer :).


| Name: Tim Nelson                 | Because the Creator is,        |
| E-mail: [EMAIL PROTECTED]    | I am                           |

Version 3.12
GCS d+++ s+: a- C++$ U+++$ P+++$ L+++ E- W+ N+ w--- V- PE(+) Y+>++ PGP->+++ R(+) !tv b++ DI++++ D G+ e++>++++ h! y-

Reply via email to