If I decide to use Rationals in Ruby for a console application, but don't want them displayed as a fraction, is there an idiomatic way to specify they should be displayed in decimal notation?
Options I know about include:
fraction = Rational(1, 2)
puts "Use to_f: #{fraction.to_f}"
puts(sprintf("Use sprintf %f", fraction))
class Rational
def to_s
to_f.to_s
end
end
puts "Monkey patch Rational#to_s: #{fraction}"
Are there any alternatives?
You can use %g in the sprintf to get the 'right' precision:
puts "%g" % Rational(1,2)
#=> 0.5
I'd personally monkey patch rational as you have, but then I'm a fan of monkey patching. Overriding the built-in to_s behavior seems entirely appropriate for a console application.
Perhaps you have another alternative where you write your own console that defines Object#to_console to call to_s, and then you could monkey patch in your own Rational#to_console instead. That extra effort would make it safer for the 0.1% chance that some library is using Rational#to_s already in a way that will break with your patch.