Benchmarking map and compact vs each_with_object vs inject

bench.rb

require 'benchmark'

words = File.open('/usr/share/dict/words', 'r') do |file|
  file.each_line.take(100_000).map(&:chomp)
end

Benchmark.bmbm(20) do |x|
  GC.start
  x.report("map") do
    words.map do |word|
      word if word.size > 5
    end
    .compact
  end

  GC.start
  x.report("each_with_object") do
    words.each_with_object([]) do |word, long_words|
      long_words << word if word.size > 5
    end
  end

  GC.start
  x.report("inject") do
    words.inject([]) do |memo, word|
      memo << word if word.size > 5
      memo
    end
  end

  GC.start
  x.report("select") do
    words.select do |word|
      word.size > 5
    end
  end
end

results.txt

Rehearsal --------------------------------------------------------
map                    0.010000   0.000000   0.010000 (  0.014050)
each_with_object       0.020000   0.000000   0.020000 (  0.020350)
inject                 0.020000   0.000000   0.020000 (  0.017213)
select                 0.010000   0.000000   0.010000 (  0.018353)
----------------------------------------------- total: 0.060000sec

                           user     system      total        real
map                    0.010000   0.000000   0.010000 (  0.011882)
each_with_object       0.010000   0.010000   0.020000 (  0.017177)
inject                 0.020000   0.000000   0.020000 (  0.017326)
select                 0.010000   0.000000   0.010000 (  0.011077)




Rehearsal --------------------------------------------------------
map                    0.010000   0.000000   0.010000 (  0.012690)
each_with_object       0.020000   0.010000   0.030000 (  0.016924)
inject                 0.010000   0.000000   0.010000 (  0.018579)
select                 0.020000   0.000000   0.020000 (  0.018294)
----------------------------------------------- total: 0.070000sec

                           user     system      total        real
map                    0.010000   0.000000   0.010000 (  0.011580)
each_with_object       0.010000   0.000000   0.010000 (  0.016984)
inject                 0.010000   0.000000   0.010000 (  0.018552)
select                 0.010000   0.000000   0.010000 (  0.011182)




Rehearsal --------------------------------------------------------
map                    0.010000   0.000000   0.010000 (  0.012689)
each_with_object       0.010000   0.000000   0.010000 (  0.016983)
inject                 0.020000   0.010000   0.030000 (  0.018153)
select                 0.020000   0.000000   0.020000 (  0.018138)
----------------------------------------------- total: 0.070000sec

                           user     system      total        real
map                    0.010000   0.000000   0.010000 (  0.011877)
each_with_object       0.020000   0.000000   0.020000 (  0.016739)
inject                 0.020000   0.000000   0.020000 (  0.018349)
select                 0.010000   0.000000   0.010000 (  0.011309)