From: Paul Mckibbin <pmckibbin@...>
Date: 2008-03-11T08:08:43+09:00
Subject: Re: shortcut for x = [x] unless x.is_a?(Array)

Aryk Grosz wrote:
> Is there any prettier or cleaner way to write
> 
>  x = [x] unless x.is_a?(Array)

Lots of caveats, caution and make sure you really, really are thinking 
about what you are trying to do. But with that note of skepticism 
aside.......

I'd guess what you really want is:

x=Array(x)

This will give you the same behaviour for String, Fixnum, TrueClass, 
Regexp and Array as your line, and is probably more what you want for 
Nil, Range and Hash. I'm second guessing, but this may not be the wisest 
way of writing your code.

Are you trying to get around the fact that x=x.to_a default behavior 
will be obsoleted in v1.9?

Make sure that is really what you want.

The answer depends on what you are trying to convert from. I'd use 
something like this to make sure this is really what you want to 
achieve.

TEST=[[1,2,3],(1..3),{:a=>:b},1,"test",true,nil,/123/]

TEST.each do |x|
  puts x.class
  puts '============================'
  puts "#{x.inspect}.to_a => #{x.to_a.inspect}"
  puts "[#{x.inspect}] => #{([x]).inspect}"
  puts "Array(#{x.inspect}) => #{Array(x).inspect}"
  puts '============================'
end


OUTPUT
============================
[1, 2, 3].to_a => [1, 2, 3]
[[1, 2, 3]] => [[1, 2, 3]]          <----- this seems to be the only 
case that you are catering for
Array([1, 2, 3]) => [1, 2, 3]
============================
Range
============================
1..3.to_a => [1, 2, 3]
[1..3] => [1..3]
Array(1..3) => [1, 2, 3]
============================
Hash
============================
{:a=>:b}.to_a => [[:a, :b]]
[{:a=>:b}] => [{:a=>:b}]
Array({:a=>:b}) => [[:a, :b]]
============================
Fixnum
============================
1.to_a => [1]
[1] => [1]
Array(1) => [1]
============================
String
============================
"test".to_a => ["test"]
["test"] => ["test"]
Array("test") => ["test"]
============================
TrueClass
============================
true.to_a => [true]
[true] => [true]
Array(true) => [true]
============================
NilClass
============================
nil.to_a => []
[nil] => [nil]
Array(nil) => []
============================
Regexp
============================
/123/.to_a => [/123/]
[/123/] => [/123/]
Array(/123/) => [/123/]
============================
-- 
Posted via http://www.ruby-forum.com/.