How do I create a hash in Ruby that compares strings, ignoring case?

Question

In Ruby, I want to store some stuff in a Hash, but I don\'t want it to be case-sensitive. So for example:

h = Hash.new
h[\"HELLO\"] = 7
puts h[\"hello\"]
         


        

Answer 1

While Ryan McGeary's approach works great and is almost certainly the correct way to do it, there is a bug that I haven't been able to discern the cause of, which breaks the Hash[] method.

For example:

r = CaseInsensitiveHash['ASDF', 1, 'QWER', 2]
=> {"ASDF"=>1, "QWER"=>2}
r['ASDF']
=> nil
ap r
{
    "ASDF" => nil,
    "QWER" => nil
}
=> {"ASDF"=>1, "QWER"=>2}

Although I've not been able to find or fix the underlying cause of the bug, the following hack does ameliorate the problem:

r = CaseInsensitiveHash.new(Hash['ASDF', 1, 'QWER', 2])
=> {"asdf"=>1, "qwer"=>2}
r['ASDF']
=> 1
ap r
{
    "asdf" => 1,
    "qwer" => 2
}
=> {"asdf"=>1, "qwer"=>2}