From: shyouhei@...
Date: 2018-04-18T07:57:15+00:00
Subject: [ruby-core:86573] [Ruby trunk Bug#14695] [2.5.1] `===` is 1.77x	slower than `match?`

Issue #14695 has been updated by shyouhei (Shyouhei Urabe).


baweaver (Brandon Weaver) wrote:
> It appears that `===` is running a bit slower than `match?`

Accurate observation.  Regexp#match? was introduced as a "faster alternative" to ordinary matches; see also https://bugs.ruby-lang.org/issues/8110


----------------------------------------
Bug #14695: [2.5.1] `===` is 1.77x slower than `match?`
https://bugs.ruby-lang.org/issues/14695#change-71512

* Author: baweaver (Brandon Weaver)
* Status: Open
* Priority: Normal
* Assignee: 
* Target version: 
* ruby -v: ruby 2.5.1p57 (2018-03-29 revision 63029) [x86_64-darwin17]
* Backport: 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN
----------------------------------------
Was evaluating some of the `===` implementations while testing and came across this one:

~~~ ruby
# ruby 2.5.1p57 (2018-03-29 revision 63029) [x86_64-darwin17]

require 'benchmark/ips'

def run_benchmark(title, **benchmarks)
  puts '', title, '=' * title.size, ''

  # Validation
  benchmarks.each do |benchmark_name, benchmark_fn|
    puts "#{benchmark_name} result: #{benchmark_fn.call()}"
  end

  puts

  Benchmark.ips do |bm|
    benchmarks.each do |benchmark_name, benchmark_fn|
      bm.report(benchmark_name, &benchmark_fn)
    end

    bm.compare!
  end
end

regex = /foo/
# => /foo/
string = 'foobarbaz'
# => "foobarbaz"

run_benchmark('=== vs match? - 2.5.1',
  '===':    -> { regex === string },
  'match?': -> { regex.match? string }
)

=== vs match? - 2.5.1
=====================

=== result: true
match? result: true

Warming up --------------------------------------
                 ===   173.435k i/100ms
              match?   233.124k i/100ms
Calculating -------------------------------------
                 ===      3.174M (�� 1.6%) i/s -     15.956M in   5.029027s
              match?      5.626M (�� 2.5%) i/s -     28.208M in   5.016991s

Comparison:
              match?:  5626170.1 i/s
                 ===:  3173659.6 i/s - 1.77x  slower
~~~

It appears that `===` is running a bit slower than `match?`, though there may be some concerns around old code potentially relying on regex set globals after `===` too in case statements, so not sure there.



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