From: "David A. Black" <dblack@...>
Date: 2008-06-18T15:37:52+09:00
Subject: Re: quick question about how array objects are handled

Hi --

On Wed, 18 Jun 2008, ara.t.howard wrote:

>
> On Jun 17, 2008, at 9:46 PM, Chance Dinkins wrote:
>
>> Thanks guys, I apperciate it - these.. dynamic methods (is that what
>> they are considered?) are a little strange to me.
>
> they are normal functions but one's which take anonymous functions (blocks) 
> as arguments.  ruby makes this very easy on the eyes, but even C has this 
> concept: do a 'man qsort' and you'll see
>
>    void
>    qsort(void *base, size_t nel, size_t width, int (*compar)(const void *, 
> const void *));
>
> note the 'compar' function you can pass in.  so, in c, you have to define 
> that function up front and then pass a pointer to it.  in ruby you can do 
> things like
>
> compar = lambda{|a,b| a <=> b}
>
> array.qsort &compar
>
> or, more compactly
>
> array.qsort{|a,b| a <=> b}
>
> of course the method is called 'sort' and not 'qsort', but the principle is 
> exactly the same.

I'd leave room, though, for the fact that in Ruby, you can provide a
code block to a method, as part of the syntax of the method call, but
you can also send anonymous functions in the argument list. So there's
a sense of "The Block", so to speak, separate from any functions you
might include as regular arguments. (Yes, I do know about the &block
idiom in method signatures :-)


David

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