Ko1 at RubyConf 2014: Massive Garbage Collection Speedup in Ruby 2.2

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31 pointstimr5 comments

> In Ruby 2.2, symbols will be garbage collected like all other Ruby objects

This sounds like it must be an oversimplification. What benefit do symbols have over strings, other than immutability? I thought their persistence in memory was a main selling point for using them as hash keys, for instance.

I don't think persistence in memory was the selling point. The other selling point is that doing comparisons are faster because `:a == :a` can compare on a memory address while `'a' == 'a'` requires comparing the data at the different memory addresses.

Someone tell me I'm wrong.

You're right. Also they symbols won't be garbage collected if they are currently keys in a hash.

symbols should also be instantiated at most once causing possible memory savings, but recent rubys should do that for frozen strings too.

This is awesome and I'm really looking forward to the fruits of the Ruby team's much-appreciated hard work.

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