case VS conditional & range VS comparison

benchmark.txt

Rehearsal ----------------------------------------------------------------
case_comparison                0.690000   0.000000   0.690000 (  0.702333)
case_range                     4.810000   0.020000   4.830000 (  4.958253)
case_predefined_range          2.880000   0.010000   2.890000 (  2.933686)
conditional_comparison         0.690000   0.000000   0.690000 (  0.705765)
conditional_range              4.560000   0.010000   4.570000 (  4.610029)
conditional_predefined_range   2.730000   0.000000   2.730000 (  2.771041)
------------------------------------------------------ total: 16.400000sec

                                   user     system      total        real
case_comparison                0.680000   0.000000   0.680000 (  0.691518)
case_range                     4.630000   0.010000   4.640000 (  4.696290)
case_predefined_range          2.890000   0.000000   2.890000 (  2.930034)
conditional_comparison         0.680000   0.000000   0.680000 (  0.691655)
conditional_range              4.450000   0.010000   4.460000 (  4.500384)
conditional_predefined_range   2.690000   0.010000   2.700000 (  2.728140)

case_vs_conditional_range_vs_comparison.rb

require 'benchmark'

N = 10_000_000

NUMBERS = N.times

LOWER_BOUND = N / 3
UPPER_BOUND = LOWER_BOUND * 2

UPPER_RANGE = UPPER_BOUND...Float::INFINITY
LOWER_RANGE = 0...LOWER_BOUND

def case_comparison(n)
  case
  when n  >= UPPER_BOUND
    3
  when n < LOWER_BOUND
    1
  else
    2
  end
end

def case_range(n)
  case n
  when UPPER_BOUND...Float::INFINITY
    3
  when 0...LOWER_BOUND
    1
  else
    2
  end
end

def case_predefined_range(n)
  case n
  when UPPER_RANGE
    3
  when LOWER_RANGE
    1
  else
    2
  end
end

def conditional_comparison(n)
  if n >= UPPER_BOUND
    3
  elsif n < LOWER_BOUND
    1
  else
    2
  end
end

def conditional_range(n)
  if (UPPER_BOUND...Float::INFINITY) === n
    3
  elsif (0...LOWER_BOUND) === n
    1
  else
    2
  end
end

def conditional_predefined_range(n)
  if UPPER_RANGE === n
    3
  elsif LOWER_RANGE === n
    1
  else
    2
  end
end

Benchmark.bmbm do |x|
  x.report('case_comparison') { NUMBERS.each { |n| case_comparison(n) } }
  x.report('case_range') { NUMBERS.each { |n| case_range(n) } }
  x.report('case_predefined_range') { NUMBERS.each { |n| case_predefined_range(n) } }

  x.report('conditional_comparison') { NUMBERS.each { |n| conditional_comparison(n) } }
  x.report('conditional_range') { NUMBERS.each { |n| conditional_range(n) } }
  x.report('conditional_predefined_range') { NUMBERS.each { |n| conditional_predefined_range(n) } }
end