From: John Mair <jrmair@...>
Date: 2010-11-12T16:51:07+09:00
Subject: Re: what's an object?

@Josh,

I agree with Yehuda too. But I do not feel the case of Method 
objects/methods is analogous to the case of blocks/procs. The 
fundamental reason is that a very crucial point of Yehuda's argument is 
that when you on-pass the block it has the same object_id; in fact in 
Yehuda's article this point is mentioned multiple times culiminating in 
this statement:

"You can tell that blocks are not being semantically wrapped and 
unwrapped
because blocks passed along via & share the same object_id across 
methods."

This semantic wrapping/unwrapping on the other hand is EXACTLY what's 
happening in the case of methods and method objects. In other words, 
what is happening with methods/method objects is precisely what Yehuda 
was arguing was *not* happening with blocks/procs.

Yehuda's argument *would* apply to methods/method objects if the 
object_id remained the same across multiple calls to the method method. 
Read what he wrote again, the persistent object_id is a big part of his 
argument.

To try to maintain the mental model that a method is really an object is 
actually impossible if the object keeps changing ;)

It is not impossible in the case of blocks/procs however, as the 
object_id remains the same.

One last example to drive it home:

method(:puts).instance_variable_set(:@hello, :hello)
method(:puts).instance_variagle_get(:@hello) #=> nil

John

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