[ruby-core:49660] [ruby-trunk - Bug #6203] Array#values_at does not handle ranges with end index past the end of the array

Issue #6203 has been updated by matz (Yukihiro Matsumoto).


This is a spec change in 2.0 unless any big compatibility problem arise.
Array#values_at should be define as:

  def values_at(*idx)
    idx.map{|i| self[i]}
  end

So it should be written in the NEWS file.

Matz.


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Bug #6203: Array#values_at does not handle ranges with end index past the end of the array
https://bugs.ruby-lang.org/issues/6203#change-33177

Author: ferrous26 (Mark Rada)
Status: Open
Priority: Normal
Assignee: nobu (Nobuyoshi Nakada)
Category: core
Target version: 2.0.0
ruby -v: trunk


=begin
When I use Array#values_at I expect that it would be the same as successive calls to (({Array#[]})).

There is one case where this does not hold:

    a = [0,1,2,3,4,5]
    a[4..6] # => [4, 5]
    a.values_at(4..6) # => [4,5,nil]

I think this is an inconsistency in the design of (({Array#values_at})). We can look at a more extreme case:

    a[4..100] # => [4, 5]
    a.values_at 4..100 # => [4, 5, nil]

And now it doesn't make any sense.

I think the best solution would be to make (({Array#values_at})) be equivalent to successive calls to (({Array#[]})). I have patched (({rb_range_beg_len()})) to handle the extra case and opened a pull request on github.
=end


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