From: John Pritchard-williams <monojohnny@...>
Date: 2008-09-01T22:30:46+09:00
Subject: Re: accessing instance variable

Additionally:

c = o.b

This always means: "run the _method_ 'b' on object 'o'" - not "give me 
the instance variable called 'b' on object 'o'": instance variables are 
never in scope outside of the class definition. (So they would be 
'private' instance variables in Java for instance).

I just thought it was worth making that point - the stack trace you 
provided shows that this is going on - its complaining about 'no such 
method', rather than 'no such instance variable' or something like that.

This tallies up by the way with the fact that Ruby allows optional 
brackets ("parentheses" depending on where you are from) for method 
calls.

"c=o.b" is equivalent to "c=o.b()".

So you get code that *looks* like its reading a instance variable, but 
really its executing a method.

John


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