Bug #5406: inconsistent odd-length array rejection in Hash[*ary] vs Hash[ary]

• Status: Closed
• Assignee: nobu (Nobuyoshi Nakada)
• Target version: 2.0.0
• ruby -v: ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-linux]

[sunaku (Suraj Kurapati)]

Hello,

Hash[*ary] raises an error when given odd number of arguments:

Hash.[]( 1, 2, 3 )
ArgumentError: odd number of arguments for Hash
from (irb):3:in []' from (irb):3 from /usr/bin/irb:12:in '

In contrast, Hash[ary] silently accepts odd-length arrays:

Hash.[]( [1, 2, 3] )
{}
Hash.[]( [[1, 2], 3] )
{
1 => 2
}
Hash.[]( [[1, 2], [3]] )
{
1 => 2,
3 => nil
}
Hash.[]( [[1, 2], [3,4,5]] )
{
1 => 2
}

I think this behavior is inconsistent. Please either:

(1) change Hash[ary] to raise errors upon seeing odd-length arrays or

(2) change Hash[*ary] to not raise an error for odd number of arguments and instead accept the last odd argument as a key with value nil, just like this existing behavior:

Hash.[]( [[1, 2], [3]] )
{
1 => 2,
3 => nil
}

Thanks for your consideration.

[ko1 (Koichi Sasada)]

• Category set to core
• Status changed from Open to Assigned
• Assignee set to matz (Yukihiro Matsumoto)

[matz (Yukihiro Matsumoto)]

• Assignee changed from matz (Yukihiro Matsumoto) to nobu (Nobuyoshi Nakada)

Hash should raise an exception, when invalid input comes.

Matz.

[nobu (Nobuyoshi Nakada)]

• Status changed from Assigned to Closed
• % Done changed from 0 to 100

This issue was solved with changeset r36391.
Suraj, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

hash.c: raise on invalid input

• hash.c (rb_hash_s_create): raise an exception, when input elements
  are not one or two elements arrays. [ruby-core:39945] [Bug #5406]