Re^4: Operator overloading with returning lists?

I have a sublanguage called "DPath" (inspired by XPath) which is used like this:

    $data = ...# some Perl data structure
    @resultlist = dpath('/AAA/BBB/*/CCC')->match($data);
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In @resultlist are all elements of $data which match the path '/AAA/BBB/*/CCC'. Due to its "matching nature" this could imho look more naturally when expressed with an overloaded '~~' (and maybe some prototype "dpath($)"), like this:

    $data = ...# some Perl data structure
    @resultlist = $data ~~ dpath '/AAA/BBB/*/CCC';
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That's what I want to do.

The dpath() function returns an object of a class to which I hoped to bind the overloading.

Thanks,
Steffen

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Re^5: Operator overloading with returning lists? by ikegami (Patriarch) on Dec 02, 2008 at 14:34 UTC
I have a sublanguage called "DPath" (inspired by XPath) Interesting. I wonder why XPath wasn't used? All the examples in the Synopsis are also valid and equivalent XPaths. It's not all that much work either, since XML::XPathEngine can be used to add XPath support to any tree class.	[reply]
Re^6: Operator overloading with returning lists? by renormalist (Sexton) on Dec 04, 2008 at 20:15 UTC
Actually if you look on CPAN there is a fork of `XML::XPath` done by James G. Smith as developer version. I experimented with it and it really worked for initial examples. Unfortunately data structures differ from XML documents in various aspects: XML elements can be repeated but not in hashes, hash keys can be as strange as you like in contrast to element names. Arrays starting with index 1 in XPath is confusing to read on data structures. And a lot of code complexity for XML that's useless on data structures: for namespaces, attributes, etc., and missing features the other way around: eg. testing for the blessed types. That's why I restarted it, with kind permission of James G. Smith to use his namespace. Not that I already have all the features, of course ...	[reply]