Issue #6203 has been updated by marcandre (Marc-Andre Lafortune).


matz (Yukihiro Matsumoto) wrote:
> The trailing nil must be a bug.

Was there a reason to change the behavior of `[].values_at(42..100)`? Could this not lead to incompatibilities?

Nobu: is there a reason not to fix `rb_range_beg_len` also as per [ruby-core:43811]?
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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-28150

Author: ferrous26 (Mark Rada)
Status: Closed
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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