String#=~ faster than String#match

[schneems]

If you're only looking for presence of a match and don't need the matchdata, use String#=~

schneems/rails@1bf50ba#commitcomment-12572839

[Arcovion]

Regexp#=== is a tiny bit faster on my machine, worth including:

require'benchmark/ips'deffastest/boo/ === 'foo'.freezeenddeffast'foo'.freeze =~ /boo/enddefslow'foo'.freeze.match(/boo/)endBenchmark.ipsdo |bm|
bm.report("Regexp#==="){fastest}bm.report("String#=~"){fast}bm.report("String#match"){slow}bm.compare!end

Calculating -------------------------------------
Regexp#=== 116.319k i/100ms
String#=~ 119.576k i/100ms
String#match 102.506k i/100ms
-------------------------------------------------
Regexp#=== 3.048M (± 1.5%) i/s - 15.238M
String#=~ 2.988M (± 1.4%) i/s - 14.947M
String#match 2.482M (± 1.2%) i/s - 12.506M
Comparison:
Regexp#===: 3047884.6 i/s
String#=~: 2988148.2 i/s - 1.02x slower
String#match: 2481615.6 i/s - 1.23x slower

[schneems]

Yep

Calculating -------------------------------------
String#=~ 66.023k i/100ms
String#match 60.124k i/100ms
String#=== 70.747k i/100ms
-------------------------------------------------
String#=~ 1.798M (±10.3%) i/s - 8.913M
String#match 1.374M (± 9.7%) i/s - 6.854M
String#=== 1.847M (± 9.8%) i/s - 9.197M

Seems good. How should I report this? I would like to have all 3 examples in the code and reported.

[Arcovion]

Edited my comment as String#=== was wrong, I meant Regexp#===
Added example of how it might look...

[JuanitoFatas]

How about list all possibilities (code/string/===-vs-=~-vs-match.rb)?

require"benchmark/ips"deffastest"foo".freeze === /boo/enddeffaster"foo".freeze =~ /boo/enddeffast/boo/ === "foo".freezeenddefslow"foo".freeze.match(/boo/)endBenchmark.ipsdo |x|
x.report("String#==="){fastest}x.report("Regexp#==="){faster}x.report("String#=~"){fast}x.report("String#match"){slow}x.compare!end

ruby -v code/string/match-vs-=\~.rb
ruby 2.2.2p95 (2015-04-13 revision 50295) [x86_64-darwin14]
Calculating -------------------------------------
String#=== 143.440k i/100ms
Regexp#=== 94.853k i/100ms
String#=~ 91.999k i/100ms
String#match 88.397k i/100ms
-------------------------------------------------
String#=== 5.637M (± 7.4%) i/s - 28.114M
Regexp#=== 2.599M (± 5.4%) i/s - 12.995M
String#=~ 2.318M (± 7.7%) i/s - 11.592M
String#match 1.905M (± 8.4%) i/s - 9.458M
Comparison:
String#===: 5637360.8 i/s
Regexp#===: 2599326.4 i/s - 2.17x slower
String#=~: 2318149.8 i/s - 2.43x slower
String#match: 1905484.8 i/s - 2.96x slower

❓

[Arcovion]

String#=== doesn't work, it's not the correct result.

[JuanitoFatas]

String#=== doesn't work, it's not the correct result.

Yup. The #59 (comment) is wrong.

Let's keep this simple since the regexp need to flip the string to be compared to the end. Which is counterintuitive

[schneems]

It's a pretty big speed boost, we would have to rename it to Regexp#=== and we could put a warning in about not switching the arguments cause you'll get the wrong results