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| author | Anuraag Agrawal <anuraaga@gmail.com> | 2022-06-10 05:41:02 +0000 |
|---|---|---|
| committer | Gopher Robot <gobot@golang.org> | 2022-09-14 14:56:07 +0000 |
| commit | 9503bcae2b20d290332d00d78672881b7fcfedf0 (patch) | |
| tree | ff6b38dda4be3cfbc52698871aa95f4da775fa25 /src/strings/strings.go | |
| parent | d60e51e3539986fcca331cc27f4730a4fe266149 (diff) | |
| download | go-9503bcae2b20d290332d00d78672881b7fcfedf0.tar.xz | |
strings: reuse the input string for Repeat count of 1
The existing implementation allocates a new string even when the
count is 1, where we know the output is the same as the input.
While we wouldn't expect a count of 1 for hardcoded values of the
parameter, it is expected when the parameter is computed based on
a different value (e.g., the length of a input slice).
name old time/op new time/op delta
Repeat/5x0-10 2.03ns ± 0% 2.02ns ± 0% ~ (p=1.000 n=1+1)
Repeat/5x1-10 13.7ns ± 0% 2.0ns ± 0% ~ (p=1.000 n=1+1)
Repeat/5x2-10 18.2ns ± 0% 18.1ns ± 0% ~ (p=1.000 n=1+1)
Repeat/5x6-10 27.0ns ± 0% 27.0ns ± 0% ~ (p=1.000 n=1+1)
Repeat/10x0-10 2.02ns ± 0% 2.02ns ± 0% ~ (p=1.000 n=1+1)
Repeat/10x1-10 16.1ns ± 0% 2.0ns ± 0% ~ (p=1.000 n=1+1)
Repeat/10x2-10 20.8ns ± 0% 20.9ns ± 0% ~ (p=1.000 n=1+1)
Repeat/10x6-10 29.2ns ± 0% 29.4ns ± 0% ~ (p=1.000 n=1+1)
Change-Id: I48e08e08f8f6d6914d62b3d6a61d563d637bec59
GitHub-Last-Rev: 068f58e08b8f5c4105e7a210f242ca1ff3a61177
GitHub-Pull-Request: golang/go#53321
Reviewed-on: https://go-review.googlesource.com/c/go/+/411477
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Keith Randall <khr@google.com>
Diffstat (limited to 'src/strings/strings.go')
| -rw-r--r-- | src/strings/strings.go | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/src/strings/strings.go b/src/strings/strings.go index 1e8de2bc34..7cf3686569 100644 --- a/src/strings/strings.go +++ b/src/strings/strings.go @@ -523,8 +523,11 @@ func Map(mapping func(rune) rune, s string) string { // It panics if count is negative or if // the result of (len(s) * count) overflows. func Repeat(s string, count int) string { - if count == 0 { + switch count { + case 0: return "" + case 1: + return s } // Since we cannot return an error on overflow, |