bench_stringscanner.rb

require "benchmark/ips"
require "strscan"

string = "abc" * 10_000

Benchmark.ips do |x|
  x.report("scan") do
    accum = ""
    string.scan(/\w/) { |m| accum = m }
  end

  x.report("stringscanner") do
    accum = ""
    scanner = StringScanner.new(string)
    loop do
      break if scanner.eos?
      accum = scanner.scan(/\w/)
    end
  end

  x.compare!
end

# ruby 3.2.2 (2023-03-30 revision e51014f9c0) [arm64-darwin22]
#
# Warming up --------------------------------------
#                 scan    12.000  i/100ms
#        stringscanner    32.000  i/100ms
# Calculating -------------------------------------
#                 scan    119.745  (± 2.5%) i/s -    600.000  in   5.014112s
#        stringscanner    328.416  (± 1.5%) i/s -      1.664k in   5.067770s

# Comparison:
#        stringscanner:      328.4 i/s
#                 scan:      119.7 i/s - 2.74x  (± 0.00) slower