(https://github.com/ruby/strscan/pull/106)
It supports non-head match cases such as StringScanner#scan_until.
If we use a String as a pattern, we can improve match performance.
Here is a result of the including benchmark.
## CRuby
It shows String as a pattern is 1.18x faster than Regexp as a pattern.
```
$ benchmark-driver benchmark/check_until.yaml
Warming up --------------------------------------
regexp 9.403M i/s - 9.548M times in 1.015459s (106.35ns/i)
regexp_var 9.162M i/s - 9.248M times in 1.009479s (109.15ns/i)
string 8.966M i/s - 9.274M times in 1.034343s (111.54ns/i)
string_var 11.051M i/s - 11.190M times in 1.012538s (90.49ns/i)
Calculating -------------------------------------
regexp 10.319M i/s - 28.209M times in 2.733707s (96.91ns/i)
regexp_var 10.032M i/s - 27.485M times in 2.739807s (99.68ns/i)
string 9.681M i/s - 26.897M times in 2.778397s (103.30ns/i)
string_var 12.162M i/s - 33.154M times in 2.726046s (82.22ns/i)
Comparison:
string_var: 12161920.6 i/s
regexp: 10318949.7 i/s - 1.18x slower
regexp_var: 10031617.6 i/s - 1.21x slower
string: 9680843.7 i/s - 1.26x slower
```
## JRuby
It shows String as a pattern is 2.11x faster than Regexp as a pattern.
```
$ benchmark-driver benchmark/check_until.yaml
Warming up --------------------------------------
regexp 7.591M i/s - 7.544M times in 0.993780s (131.74ns/i)
regexp_var 6.143M i/s - 6.125M times in 0.997038s (162.77ns/i)
string 14.135M i/s - 14.079M times in 0.996067s (70.75ns/i)
string_var 14.079M i/s - 14.057M times in 0.998420s (71.03ns/i)
Calculating -------------------------------------
regexp 9.409M i/s - 22.773M times in 2.420268s (106.28ns/i)
regexp_var 10.116M i/s - 18.430M times in 1.821820s (98.85ns/i)
string 21.389M i/s - 42.404M times in 1.982519s (46.75ns/i)
string_var 20.897M i/s - 42.237M times in 2.021187s (47.85ns/i)
Comparison:
string: 21389191.1 i/s
string_var: 20897327.5 i/s - 1.02x slower
regexp_var: 10116464.7 i/s - 2.11x slower
regexp: 9409222.3 i/s - 2.27x slower
```
See:
be7815ec02/core/src/main/java/org/jruby/util/StringSupport.java (L1706-L1736)
---------
https://github.com/ruby/strscan/commit/f9d96c446a
Co-authored-by: Sutou Kouhei <kou@clear-code.com>
integers
(https://github.com/ruby/strscan/pull/89)
This commit adds `scan_byte` and `peek_byte`. `scan_byte` will scan the
current byte, return it as an integer, and advance the cursor.
`peek_byte` will return the current byte as an integer without advancing
the cursor.
Currently `StringScanner#get_byte` returns a string, but I want to get
the current byte without allocating a string. I think this will help
with writing high performance lexers.
---------
https://github.com/ruby/strscan/commit/873aba2e5d
Co-authored-by: Sutou Kouhei <kou@clear-code.com>
rb_reg_onig_match performs preparation, error handling, and cleanup for
matching a regex against a string. This reduces repetitive code and
removes the need for StringScanner to access internal data of regex.
If we use the same version as the default strscan gem in Ruby, "gem
install" doesn't extract .gem. It fails "gem install" because "gem
install" can't find ext/strscan/ to be built.
https://github.com/ruby/strscan/commit/3ceafa6cdc
iff means if and only if, but readers without that knowledge might
assume this to be a spelling mistake. To me, this seems like
exclusionary language that is unnecessary. Simply using "if and only if"
instead should suffice.
https://github.com/ruby/strscan/commit/066451c11e
NAITOH Jun
Nobuyoshi Nakada
Hiroshi SHIBATA
Burdette Lamar
卜部昌平
Aaron Patterson
Sutou Kouhei
Peter Zhu
Matt Valentine-House
OKURA Masafumi
Gannon McGibbon
Kenichi Kamiya
Jeremy Evans
Kenta Murata
Kenta Murata