From: dblack@...
Date: 2006-12-26T08:12:00+09:00
Subject: Re: Merry (slightly early) Christmas! Mr. Neighborly's Humble Little Ruby Book is free!

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Hi --

On Tue, 26 Dec 2006, Jeremy McAnally wrote:

> On 12/22/06, Tyler Prete <psyonic@gmail.com> wrote:
>> This book is really great!  I'm familiar with most of the material alrea=
dy,
>> but I'm enjoying reading through it all the same.  One question I have (=
a
>> question of preference more than correctness) is in your example dealing
>> with blocks and yield, why do you choose to use while with an interator:
>>=20
>> def myeach(myarray)
>>   iter =3D 0
>>   while (iter < myarray.length):
>>     yield(myarray[iter])
>>     iter +=3D 1
>>   end
>> end
>> testarray =3D [1,2,3,4,5]
>> myeach(testarray) {|item| print "#{item}:"}
>> =A2=AA 1:2:3:4:5:
>>=20
>> Rather than using what seems (to me at least) the more Ruby way:
>>=20
>> def myeach(myarray)
>>   for elem in myarray
>>     yield elem
>>   end
>> end
>>=20
>> That way you're not using an extra variable or having to worry about arr=
ay
>> length.
>>=20
>> A funny way to write it would be using blocks:
>> def myeach(myarray)
>>   myarray.each { |elem| yield(elem) }
>> end
>>=20
>> but I think that way basically defeats the purpose of your example ;)
>>=20
>> Anyway, I'm just interested in your thoughts about this.  You most likel=
y
>> have your reasons and they probably make sense; after all, you're the on=
e
>> out there writing books :)
>>=20
> Hey Tyler,
> While thats the most Rubyish way to do it, at that point in the text I
> hadn't covered those sorts of loops/iterators yet and thought that the
> while method would be more familiar to those reading.  I may change it
> in the next revision, but I'm not sure. :)

I definitely agree that that -- dealing with forward topic references
as one writes -- is a challenge.  My favorite example is: you can't
really explain Enumerable until you've explained arrays, but Array is
Enumerable.... :-)  It is, though, a good affirmation of the fact that
Ruby is a nicely integrated system and a well-oiled machine.


David

--=20
Q. What's a good holiday present for the serious Rails developer?
A. RUBY FOR RAILS by David A. Black (http://www.manning.com/black)
    aka The Ruby book for Rails developers!
Q. Where can I get Ruby/Rails on-site training, consulting, coaching?
A. Ruby Power and Light, LLC (http://www.rubypal.com)
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