From: Tom Cloyd <tomcloyd@...>
Date: 2009-01-15T10:45:12+09:00
Subject: Re: yield example baffling - need help

Tom Cloyd wrote:
> I'm studying the yield statement for the first time, today.
>
> All's well until I see this example:
>
> def myeach(myarray)
> iter = 0
> while (iter < myarray.length):
> yield(myarray[iter])
> iter += 1
> end
> end
>
> testarray = [1,2,3,4,5]
> myeach(testarray) {|item| print "#{item}:"}
> → 1:2:3:4:5:
>
> I see a method with one parameter. There a block to the right of the 
> method call, inexplicably. It would make sense if some iteration were 
> going on, but I don't see that at all. One call, one execution (with a 
> loop), and we're out. What does "item" have to count through?
>
> How can that yield do anything? How does it know about the block? It's 
> not passed in. The iteration appears to be happening IN the method, 
> using a block it cannot possibly see. Ouch! After some minutes, I'm 
> not getting this at all.
>
> Can anyone clear my head for me. I've never seen anything like this. 
> Or is it just a weird Ruby idiom I'll just have to accept?
>
> Thanks in advance.
>
> Tom
>
>
Arrgh. What a dolt. I just realized that ALL the yield examples I've 
been studying have this block sitting over to the right - I was 
converting the curly braces to parens in my mind, and so didn't see 
them. It IS idiomatic weirdness. I yield to higher wisdom.

t.

-- 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Tom Cloyd, MS MA, LMHC - Private practice Psychotherapist
Bellingham, Washington, U.S.A: (360) 920-1226
<< tc@tomcloyd.com >> (email)
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