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rubydynamicblock

How to dynamically wrap code inside a block in Ruby?

Suppose a certain part of code needs to be run inside a different block/context, depending on a configuration option. For example,

if silence
  silence_stdout do
    # do something
  end
else
  # do the same thing
end

Is there a way to write this without repeating the # do something code?

Solution

  • Depending on how much code "do something" is you could throw it in a lambda:

    something = -> { do_something }
if silence
  silence_stdout &something
else
  something.call
end

    or throw it in a method:

    def something
  # Do something, lots and lots of something.
end

if silence
    silence_stdout &method(:something)
else
    something
end

    You could also turn the logic inside out a bit:

    def no_op
  yield
end
def silence_stdout
  # Do whatever and then...
  yield
end

m = method(silence ? :no_op : :silence_stdout)
m.call do
  # Do something
end

    Or you could use whole classes or just lambdas instead of methods in that last one.