From: Logan Capaldo <logancapaldo@...>
Date: 2006-08-18T14:34:28+09:00
Subject: Re: Perl Junkie: Bad form?


On Aug 17, 2006, at 6:05 PM, /usr/ceo wrote:

> Eero Saynatkari wrote:
>> /usr/ceo wrote:
>>> Ok where do I start? :-)  A little background...
>>>
>>> I've been declaring up and down for 6 years now I'm going to stop  
>>> using
>>> Perl and start using Ruby.  One thing that has always held me  
>>> back is
>>> not having libraries I've put together in Perl available to me in  
>>> Ruby.
>>>  Instead, I've ported little Ruby tricks over into Perl to the  
>>> extent
>>> possible.  Now I've decided the only way I'm going to use Ruby is  
>>> start
>>> porting some of the stuff I use in Perl to Ruby.
>>>
>>> Here's a little bit of a delimma I have going that I hope to  
>>> illustrate
>>> using something simple.
>>>
>>> I wrote this routine in Perl called "puts" that mostly simulates  
>>> Ruby's
>>> "puts" statement.  (I intend to illustrate something bigger than  
>>> "puts"
>>> emulation here, so don't let that drag you in.  I'm more  
>>> interested in
>>> the module interaction and EXPORTS [in Perl] and include [in Ruby]
>>> interaction...).  Here's the puts() routine in Perl:
>>>
>>> <snip explanation />
>>>
>>> This is what I would rather be doing, generally, for imported  
>>> utility
>>> type routines -- making them look "native."  I understand (pretty  
>>> much)
>>> about the separate namespace issue, and namespaces are certainly  
>>> nice
>>> (both in Perl and in Ruby).  But sometimes I want to pretend I have
>>> something "natively" available to me, and this seemed to work.
>>>
>>> Ugly?  Right?  Hackish?  A better way?  Looking for the Ruby
>>> perspective here because this is probably one of my more unsolved
>>> delimmas -- how to view, approach and implement cases like this.
>>
>> The problem is you might be tromping all over the library
>> user's namespace, possibly overriding methods etc. It is
>> better to give the 'namespace' and then allow the client
>> programmer #include the module if they desire shorter access.
>>
>> Those who remember, I actually advocate allowing the client
>> programmer create a namespace for libraries instead of the
>> library writer, too, but that is another discussion.
>
> So are you advocating this (by your last statement especially)?
>
> my/utils.rb:
>
> module Utils
>    def mputs( *args )
>       args.each { |n| puts n }
>    end # def
> end # module
>
> myscript.rb:
>
> #!/usr/bin/env ruby
>
> require 'my/utils'
> include Utils
>
> mputs(
>    "Line 1",
>    "Line 2",
>    "Line 3"
> )
>
> BTW, I am familiar with the fact the one can use "here documents" in
> Ruby as well.  Again, the simple mputs() routine was intended to
> illustrate the require/include interaction -- not to illustrate a way
> to write multiple lines (in case someone else comes along and reads it
> that way.)
>
> /usr/ceo
>
>

Yes, this is SOP. The only other thing I would suggest is for modules  
like Util (where it's just a collection of "functions" and not  
methods) is you do

module Util
   def mputs(*args)
       args.each { |item| puts item }
   end
   module_function :mputs
end

This lets you say

Util.mputs

or

include Util
mputs

similar to the Math module.