Mutable Hash Keys

Caveat. Mutable hash keys in ruby obviously behave different than you would expect:

>> foo = [1, 2, 3]
[1, 2, 3]
>> bar = {foo => 42}
{[1, 2, 3]=>42}
>> foo << 4
[1, 2, 3, 4]
>> bar[foo]
nil

Update: there is Hash#rehash.

This entry was posted on Tuesday, May 29th, 2007 at 4:42 pm and tagged as caveat, ruby, stumbledupon. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

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