Re: String not enumerable, what about IO? (was Re: Symbol < String in Ruby > 1.8)

Hi --

On Thu, 19 Oct 2006, Nikolai Weibull wrote:

> On 10/19/06, [e-mail] <[e-mail]> wrote:
>> Hi --
>> 
>> On Thu, 19 Oct 2006, Yukihiro Matsumoto wrote:
>> 
>> > Hi,
>> >
>> > In message "Re: String not enumerable, what about IO? (was Re: Symbol < 
>> String in Ruby > 1.8)"
>> >    on Thu, 19 Oct 2006 20:16:54 +0900, [e-mail] writes:
>> >
>> > |There are two separate questions involved, though:
>> > |
>> > |   1. Should there be a method to enumerate over the lines without
>> > |      creating an intermediate array?
>> > |   2. Should that method be called "lines"?
>> > |
>> > |I would say yes to #1, and no to #2.
>> >
>> > The reason behind no to #2 is that readlines returns an array, right?
>> > Then, what if I change readlines to return Enumerator?
>> 
>> I still think the naming is very unexpected.  I know it's
>> old-fashioned and naive to expect "things" to be a collection of
>> things :-)  But I really do have that expectation.
>
> I think it's rather nice, and it actually /is/ a collection of
> "things", although more of what may be thought of as a lazy list that
> will give you another one of the "things" each time you need it, not
> all at once in an array.  One really has to get away from treating all
> collections as if they're always going to be arrays of "things".
> Sadly, it's the C in us that makes us think/read/talk in that manner
> [1].

Actually in my case it's the Ruby in me :-)

> Anyway, I'd love to be able to write
>
> IO.read(file).lines.each{ |line| puts line if line =~ pattern }.

If lines were a collection of lines, you could do exactly that.  And,
just to say it again, I'm not saying that there should be no methods
that return Enumerators, just that "things" sounds (to my Ruby-trained
mind :-) like a collection/array of things.


David

-- 
                   David A. Black | [e-mail]
Author of "Ruby for Rails"   [1] | Ruby/Rails training & consultancy [3]
DABlog (DAB's Weblog)        [2] | Co-director, Ruby Central, Inc.   [4]
[1] http://www.manning.com/black | [3] http://www.rubypowerandlight.com
[2] http://dablog.rubypal.com    | [4] http://www.rubycentral.org