Bryan Boreham c5430dc1d8 regexp: allow patterns with no alternates to be one-pass ... Check whether a regex has any 'alt' instructions before rejecting it as one-pass. Previously `^abc` would run the backtrack matcher. I tried to make the comment match what the code does now. Updates #21463 ``` name old time/op new time/op delta Find-8 167ns ± 1% 170ns ± 3% ~ (p=0.500 n=5+5) FindAllNoMatches-8 88.8ns ± 5% 87.3ns ± 0% ~ (p=0.095 n=5+5) FindString-8 166ns ± 3% 164ns ± 0% ~ (p=0.063 n=5+5) FindSubmatch-8 191ns ± 1% 191ns ± 0% ~ (p=0.556 n=4+5) FindStringSubmatch-8 183ns ± 0% 182ns ± 0% -0.43% (p=0.048 n=5+5) Literal-8 50.3ns ± 0% 50.1ns ± 0% -0.40% (p=0.016 n=5+4) NotLiteral-8 914ns ± 0% 927ns ± 7% ~ (p=0.730 n=5+5) MatchClass-8 1.20µs ± 1% 1.22µs ± 6% ~ (p=0.738 n=5+5) MatchClass_InRange-8 1.20µs ± 6% 1.21µs ± 6% ~ (p=0.548 n=5+5) ReplaceAll-8 796ns ± 0% 792ns ± 0% -0.51% (p=0.032 n=5+5) AnchoredLiteralShortNonMatch-8 41.0ns ± 2% 34.2ns ± 2% -16.47% (p=0.008 n=5+5) AnchoredLiteralLongNonMatch-8 53.3ns ± 0% 34.3ns ± 3% -35.74% (p=0.008 n=5+5) AnchoredShortMatch-8 74.0ns ± 2% 75.8ns ± 0% +2.46% (p=0.032 n=5+4) AnchoredLongMatch-8 146ns ± 3% 76ns ± 1% -48.12% (p=0.008 n=5+5) OnePassShortA-8 424ns ± 0% 423ns ± 0% ~ (p=0.222 n=5+4) NotOnePassShortA-8 373ns ± 1% 375ns ± 2% ~ (p=0.690 n=5+5) OnePassShortB-8 315ns ± 2% 308ns ± 0% -2.12% (p=0.008 n=5+5) NotOnePassShortB-8 244ns ± 3% 239ns ± 0% ~ (p=0.476 n=5+5) OnePassLongPrefix-8 61.6ns ± 2% 60.9ns ± 0% -1.13% (p=0.016 n=5+4) OnePassLongNotPrefix-8 236ns ± 3% 230ns ± 0% ~ (p=0.143 n=5+5) ``` Change-Id: I8a94b53bc761cd7ec89923c905ec8baaaa58a5fd GitHub-Last-Rev: e9e0c29b74 GitHub-Pull-Request: golang/go#48748 Reviewed-on: https://go-review.googlesource.com/c/go/+/353711 Reviewed-by: Daniel Martí <mvdan@mvdan.cc> Reviewed-by: Russ Cox <rsc@golang.org> Auto-Submit: Ian Lance Taylor <iant@golang.org> Reviewed-by: Dmitri Shuralyov <dmitshur@google.com> Auto-Submit: Ian Lance Taylor <iant@google.com> LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Commit-Queue: Ian Lance Taylor <iant@google.com> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com>		2024-07-24 01:01:48 +00:00
..
syntax	regexp/syntax: cleanup code generation in perl_groups.go	2024-04-02 13:59:01 +00:00
testdata
all_test.go	regexp: use slices to simplify the code	2024-03-25 19:36:03 +00:00
backtrack.go	regexp: use built-in clear to clear b.visited in *bitState.reset	2023-09-14 17:25:39 +00:00
example_test.go	regexp: improve Regexp.ReplaceAll documentation and tests related to Expand part	2023-08-07 00:22:53 +00:00
exec2_test.go
exec_test.go	regexp: use slices to simplify the code	2024-03-25 19:36:03 +00:00
exec.go
find_test.go
onepass_test.go	regexp: allow patterns with no alternates to be one-pass	2024-07-24 01:01:48 +00:00
onepass.go	regexp: allow patterns with no alternates to be one-pass	2024-07-24 01:01:48 +00:00
regexp.go	regexp: more cross-references in docstrings	2024-07-16 20:07:41 +00:00