[ruby-core:27006] [Bug #2422] splat operator fails on array of 1 element

Issue #2422 has been updated by Dave B.


Tanaka Akira (on ruby-core) wrote:
> On Thu, Dec 3, 2009 at 2:35 AM, Raul Parolari <[e-mail]> wrote:
>> Bug #2422: splat operator fails on array of 1 element
>> http://redmine.ruby-lang.org/issues/show/2422
>
>> In Ruby 1.9.1:
>>
>> a, b = *[ 137, 271 ]  #  a = 137; b = 271  # (as expected)
>>
>> a    = *[ 137 ]      # a = [137 ]   #  (should be 137 !)
>
> The Ruby 1.9 behavior is simplified and more consistent.
>
> % ruby -ve '
> a = *[1,2,3]; p a
> a = *[1,2]; p a
> a = *[1]; p a
> a = *[]; p a'
> ruby 1.9.2dev (2009-09-24 trunk 25067) [i686-linux]
> [1, 2, 3]
> [1, 2]
> [1]
> []
>
> % ruby-1.8 -ve '
> a = *[1,2,3]; p a
> a = *[1,2]; p a
> a = *[1]; p a
> a = *[]; p a'
> ruby 1.8.8dev (2009-10-15 revision 25343) [i686-linux]
> [1, 2, 3]
> [1, 2]
> 1
> nil
>
> Ruby 1.9 doesn't handle zero or one element array specially.


But Raul's example reveals *inconsistency* from 1.9 for a balanced LHS / RHS ...


puts 'ruby %s (%s) [%s]' % [RUBY_VERSION, RUBY_RELEASE_DATE, RUBY_PLATFORM]

a,b,c,d = *[1,2,3,4]
p [a,b,c,d]

a,b,c = *[1,2,3]
p [a,b,c]

a,b = *[1,2]
p [a,b]


--
daz

a = *[1]
p [a]

=begin (output)

ruby 1.8.6 (2008-08-11) [i386-mswin32]
[1, 2, 3, 4]
[1, 2, 3]
[1, 2]
[1]

ruby 1.9.2 (2009-05-19) [i386-mswin32_90]
[1, 2, 3, 4]
[1, 2, 3]
[1, 2]
[[1]]

=end

a = *[1] (a = 1) results in a = [1]


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http://redmine.ruby-lang.org/issues/show/2422

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http://redmine.ruby-lang.org