From: Robert Klemme <shortcutter@...>
Date: 2009-02-26T17:32:50+09:00
Subject: Re: Where is splat implemented? / How does it work?

2009/2/26 minilith@gmail.com <minilith@gmail.com>:
>> > I'm pretty sure that implicit conversions to array use to_ary, not to_a.
>> > This is the way it works in Ruby 1.8, and after an experimental period in
>> > 1.9 with to_splat
>
> Building on David Black's examples, I tried the following to clarify
> the use of #to_a and #to_ary for me.
>
>> RUBY_VERSION
> => "1.9.1"
>> o = Object.new
> => #<Object:0x100af964>
>> class << o
>>     def to_a
>>         [:a]
>>     end
>>     def to_ary
>>         [:ary]
>>     end
>> end
>> [*o]
> => [:a]
>> [1] + o
> => [1, :ary]
>
> The #to_splat method seems to be gone.

Here's another test set

09:31:50 OPSC_Gold_bas_dev_R2.0_foundation$ ruby /tmp/o.rb
"1.8.7"
1
2
3
"--------------"
#<Object:0x1002dfcc>
nil
nil
"--------------"
5
6
7
"--------------"
5
6
7
"=============="
1
2
3
"--------------"
error
error
5
6
7
"--------------"
09:31:55 OPSC_Gold_bas_dev_R2.0_foundation$ ruby19 /tmp/o.rb
"1.9.1"
1
2
3
"--------------"
#<Object:0x1001a3dc>
nil
nil
"--------------"
#<Object:0x1001a378>
nil
nil
"--------------"
5
6
7
"=============="
1
2
3
"--------------"
error
error
error
09:31:57 OPSC_Gold_bas_dev_R2.0_foundation$ cat /tmp/o.rb

p RUBY_VERSION

def t(a,b,c)
  p a,b,c, '--------------'
end

o = Object.new

def o.to_a
  [1,2,3]
end

q = Object.new

def q.to_ary
  [5,6,7]
end

a, b, c = *o
p a,b,c, '--------------'

a, b, c = o
p a,b,c, '--------------'

a, b, c = *q
p a,b,c, '--------------'

a, b, c = q
p a,b,c, '=============='

t(*o) rescue puts "error"
t(o) rescue puts "error"

t(q) rescue puts "error"
t(*q) rescue puts "error"
09:32:04 OPSC_Gold_bas_dev_R2.0_foundation$

Cheers

robert


-- 
remember.guy do |as, often| as.you_can - without end