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Adding properties to a method?

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jonT

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Feb 5, 2006, 1:05:41 PM2/5/06
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Hi,

I'd like to be able to do the following:

class Method; attr_accessor :foo; end
def bar; "some_res"; end
method(:bar).foo=1

method(:bar).foo #= 1

Of coures what i'd actually get is:
method(:bar).foo #= nil

because method(:bar) returns a new object each time.

Is it possible to bind properties to a method definition? If so, how?

Thanks,
Jon

James Britt

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Feb 5, 2006, 1:29:56 PM2/5/06
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jonT wrote:
> Hi,
>
> I'd like to be able to do the following:
>
> class Method; attr_accessor :foo; end
> def bar; "some_res"; end
> method(:bar).foo=1
>
> method(:bar).foo #= 1
>
> Of coures what i'd actually get is:
> method(:bar).foo #= nil
>
> because method(:bar) returns a new object each time.

A String, in your example. Do you want the string to respond to the
message 'foo=' ?


>
> Is it possible to bind properties to a method definition? If so, how?
>

What do you mean by "bind" and "properties"?


--
James Britt

"Programs must be written for people to read, and only incidentally
for machines to execute."
- H. Abelson and G. Sussman
(in "The Structure and Interpretation of Computer Programs)


Trans

unread,
Feb 5, 2006, 1:42:53 PM2/5/06
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You can check out Facets' kernel/method.

T.

jonT

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Feb 5, 2006, 1:45:01 PM2/5/06
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>> Of coures what i'd actually get is:
>> method(:bar).foo #= nil
>> because method(:bar) returns a new object each time.
>A String, in your example. Do you want the string to respond to the
>message 'foo=' ?

method(:bar)
# => <Method: Object#bar>
method(:bar).class
# => Method

method(:bar) actually returns a method object.

>What do you mean by "bind" and "properties"?

Sorry. By bind I meant simply to set the value of a properety in the
usual way. By property I mean property: a public field.

Essentially what I'm aiming to do is to have some way of storing data
about a method (which is either private to Object or a member of some
class or module) such that it is publicly available. Example:

def cd(dir)
FileUtils.cd(dir.path)
nil
end
method(:cd).args_classes={0=>JDir}

not terribly Ruby like but you get the picture.

Jon

jonT

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Feb 5, 2006, 2:28:15 PM2/5/06
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Eric Hodel

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Feb 6, 2006, 2:33:04 PM2/6/06
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On Feb 5, 2006, at 10:08 AM, jonT wrote:

> class Method; attr_accessor :foo; end
> def bar; "some_res"; end
> method(:bar).foo=1
>
> method(:bar).foo #= 1
>
> Of coures what i'd actually get is:
> method(:bar).foo #= nil
>
> because method(:bar) returns a new object each time.

Of course! It may not be the same method. Another thread may
overwrite bar with a new implementation.

--
Eric Hodel - drb...@segment7.net - http://segment7.net
This implementation is HODEL-HASH-9600 compliant

http://trackmap.robotcoop.com


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