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Ruby memory leak: regular expressions in class methods

A few people were taking about this snippet of code today:

module Foo
  def class_name
    name.split(/::/)
  end
end

class Bar; extend Foo; end

loop { Bar.class_name }

It leaks like a old faucet. For some reason this snippet doesn’t:

module Foo
  def class_name
    x = /::/
    name.split(x)
  end
end

class Bar; extend Foo; end

loop { Bar.class_name }

It seems that it’s better to define a regex outside of a split, gsub or other similar method in a class method. I wonder if Rails does anything like this…