object pattern matching
Ara.T.Howard
i've been toying with an idea lately and thinking about how one would crawl an
object graph to determine if it matched a specifc object. for instance
array_of_hashes = [ {}, {} ]
specific_array_of_hashes = [ {'key' => 'value}, {:k => :v} ]
specific_array_of_hashes_2 = [ {:k => :v} ]
specific_array_of_hashes.is_shaped_like? array_of_hashes #=> true
so, something like pattern matching in ml languages. any concepts on how to
do that in ruby for arbitrary objects?
cheers.
-a
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James Britt
>
> i've been toying with an idea lately and thinking about how one would
> crawl an
> object graph to determine if it matched a specifc object. for instance
>
>
> array_of_hashes = [ {}, {} ]
>
> specific_array_of_hashes = [ {'key' => 'value}, {:k => :v} ]
> specific_array_of_hashes_2 = [ {:k => :v} ]
>
> specific_array_of_hashes.is_shaped_like? array_of_hashes #=> true
>
> so, something like pattern matching in ml languages. any concepts on
> how to
> do that in ruby for arbitrary objects?
>
Isn't there a Ruby project that allows one to run regexen over object
hierarchies?
James
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Ara.T.Howard
> Ara.T.Howard wrote:
>>
>> i've been toying with an idea lately and thinking about how one would crawl
>> an
>> object graph to determine if it matched a specifc object. for instance
>>
>>
>> array_of_hashes = [ {}, {} ]
>>
>> specific_array_of_hashes = [ {'key' => 'value}, {:k => :v} ]
>> specific_array_of_hashes_2 = [ {:k => :v} ]
>>
>> specific_array_of_hashes.is_shaped_like? array_of_hashes #=> true
>>
>> so, something like pattern matching in ml languages. any concepts on how
>> to
>> do that in ruby for arbitrary objects?
>>
>
> Isn't there a Ruby project that allows one to run regexen over object
> hierarchies?
dunno... i seem to recall something too but searching the raa didn't bring up
any hits?
James Britt
> On Sun, 21 Aug 2005, James Britt wrote:
>
>>
>> Isn't there a Ruby project that allows one to run regexen over object
>> hierarchies?
>
>
> dunno... i seem to recall something too but searching the raa didn't
> bring up
> any hits?
>
I was selling some folks on Ruby recently, and mentioned this project,
and I swore I had saved off the initial announcement because it struck
me as one of those things that did solve any immediate problems but
seemed so slick that I knew it would come in handy.
Now I can't find it. :(
Phil Tomson
James Britt <jam...@neurogami.com> wrote:
>Ara.T.Howard wrote:
>> On Sun, 21 Aug 2005, James Britt wrote:
>>
>>> ...
>>>
>>> Isn't there a Ruby project that allows one to run regexen over object
>>> hierarchies?
>>
>>
>> dunno... i seem to recall something too but searching the raa didn't
>> bring up
>> any hits?
>>
>
>I was selling some folks on Ruby recently, and mentioned this project,
>and I swore I had saved off the initial announcement because it struck
>me as one of those things that did solve any immediate problems but
>seemed so slick that I knew it would come in handy.
>
>
>Now I can't find it. :(
>
>
I think you're looking for Reg:
http://rubyforge.org/projects/reg/
Reg is a library for pattern matching in ruby data structures. Reg
provides Regexp-like match and match-and-replace for all data structures
(particularly Arrays, Objects, and Hashes), not just Strings.
Phil
James Britt
..
>
> I think you're looking for Reg:
>
> http://rubyforge.org/projects/reg/
>
> Reg is a library for pattern matching in ruby data structures. Reg
> provides Regexp-like match and match-and-replace for all data structures
> (particularly Arrays, Objects, and Hashes), not just Strings.
Yes! Thanks.
James
Ara.T.Howard
thanks phil! downloading now...
Eric Mahurin
From my communications with Caleb, I believe he'll be changing
the interface to look more like Regexp. This will help in
places where you have ducked-type places that deal with
Regexp-like objects. An example is some of the scan_pattern*
methods I'll be adding to Cursor (not released yet). I think
he might add the ability to operate on a Cursor directly also,
but I'm not sure about that. A Cursor by the way is something
generic that can look kind of like a Array, String, IO, C++
iterator, Java stream, etc. all rolled into one API. I have
many derived classes that operate on a variety of sequential
data structures.
In addition I'm putting together Grammar which will also be
able to operate on any sequential data structure - as long as
you can give it a subset of the Cursor API. You'll be able to
write a lexer (operates on characters) and a parser (operates
on tokens) in a uniform way. Similar to ANTLR, but more
unification.
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Phil Tomson
Eric Mahurin <eric_m...@yahoo.com> wrote:
>--- "Ara.T.Howard" <Ara.T....@noaa.gov> wrote:
>
>> On Sun, 21 Aug 2005, Phil Tomson wrote:
We eagerly await the release of Grammar.
Phil