Using the latest version of all modules known by the module proxy,
we determine that for all Trim usages (and related functionality):
* 76.6% have cutsets of len=1, and
* 13.4% have cutsets of len=2.
Given that a vast majority of usages only have a cutset of len=1,
we should more heavily optimize for that situation.
Previously, there was some optimization for cutsets of len=1,
but it's within the internal makeCutsetFunc function.
This is sub-optimal as it incurs an allocation in makeCutsetFunc
for the closure over that single byte.
This CL removes special-casing of one-byte cutsets from makeCutsetFunc
and instead distributes it directly in Trim, TrimRight, and TrimLeft.
Whether we should distribute the entire ASCII cutset logic into Trim
is a future CL that should be discussed and handled separately.
The evidence for multibyte cutsets is not as obviously compelling.
name old time/op new time/op delta
bytes/TrimByte-4 84.1ns ± 2% 7.5ns ± 1% -91.10% (p=0.000 n=9+7)
strings/TrimByte-4 86.2ns ± 3% 8.3ns ± 1% -90.33% (p=0.000 n=9+10)
Fixes#46446
Change-Id: Ia0e31a8384c3ce111ae35465605bcec45df2ebec
Reviewed-on: https://go-review.googlesource.com/c/go/+/323318
Trust: Joe Tsai <joetsai@digital-static.net>
Run-TryBot: Joe Tsai <joetsai@digital-static.net>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
The implementation for single strings had two optimization opportunities:
1. Grow the temporary buffer by known size before appending.
2. Avoid a full copy of the result since the underlying buffer won't be mutated afterward.
Both things were leveraged by using a Builder instead of a byte slice.
Relevant benchmark results:
name old time/op new time/op delta
SingleMatch-8 32.0µs ± 3% 26.1µs ± 3% -18.41% (p=0.000 n=9+10)
name old speed new speed delta
SingleMatch-8 469MB/s ± 3% 574MB/s ± 3% +22.56% (p=0.000 n=9+10)
name old alloc/op new alloc/op delta
SingleMatch-8 81.3kB ± 0% 49.0kB ± 0% -39.67% (p=0.000 n=10+10)
name old allocs/op new allocs/op delta
SingleMatch-8 19.0 ± 0% 11.0 ± 0% -42.11% (p=0.000 n=10+10)
Change-Id: I23af56a15875206c0ff4ce29a51bec95fd48bb11
GitHub-Last-Rev: 403cfc3c27
GitHub-Pull-Request: golang/go#47766
Reviewed-on: https://go-review.googlesource.com/c/go/+/343089
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Robert Griesemer <gri@golang.org>
There is no documentation on a number of methods of the strings.Reader
struct, so this change adds documentation referring to the relevant
io.* interfaces implemented. This is consistent with pre-existing
documentation in this struct.
Fixes#40381
Change-Id: I3dec65ecafca5b79d85d30a676d297e5ee9ab47e
GitHub-Last-Rev: f42429946a
GitHub-Pull-Request: golang/go#40654
Reviewed-on: https://go-review.googlesource.com/c/go/+/247523
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
Trust: Ian Lance Taylor <iant@golang.org>
The old ioutil references are still valid, but update our code
to reflect best practices and get used to the new locations.
Code compiled with the bootstrap toolchain
(cmd/asm, cmd/dist, cmd/compile, debug/elf)
must remain Go 1.4-compatible and is excluded.
Also excluded vendored code.
For #41190.
Change-Id: I6d86f2bf7bc37a9d904b6cee3fe0c7af6d94d5b1
Reviewed-on: https://go-review.googlesource.com/c/go/+/263142
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
golang.org/cl/229763 removed the documentation of requirements of
the function passed to FieldsFunc. The current implementation does
not require functions to return consistent results but this had not
been the case for previous implementations.
Add the requirement for consistent results back to the documentation
to allow for future implementations to be more allocation efficient
for an output with more than 32 fields. This is possible with a two
pass algorithm first determining the number of fields used to allocate
the output slice and then splitting the input into fields.
While at it align the documentation of bytes.FieldsFunc with
strings.FieldFunc.
Fixes#38630
Change-Id: Iabbf9ca3dff0daa41f4ec930a21a3dd98e19f122
Reviewed-on: https://go-review.googlesource.com/c/go/+/230797
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@golang.org>
The type annotation of some trim functions are inconsistent with all
other function signatures of the strings package.
Example:
func TrimRight(s string, cutset string) string
To be:
func TrimRight(s, cutset string) string
Change-Id: I456a33287bfb4ad6a7962e30a6424f209ac320c1
Reviewed-on: https://go-review.googlesource.com/c/go/+/226339
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Instead use string(r) where r has type rune.
This is in preparation for a vet warning for string(i).
Updates #32479
Change-Id: Ic205269bba1bd41723950219ecfb67ce17a7aa79
Reviewed-on: https://go-review.googlesource.com/c/go/+/220844
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Akhil Indurti <aindurti@gmail.com>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Toshihiro Shiino <shiino.toshihiro@gmail.com>
This CL adds -d=checkptr as a compile-time option for adding
instrumentation to check that Go code is following unsafe.Pointer
safety rules dynamically. In particular, it currently checks two
things:
1. When converting unsafe.Pointer to *T, make sure the resulting
pointer is aligned appropriately for T.
2. When performing pointer arithmetic, if the result points to a Go
heap object, make sure we can find an unsafe.Pointer-typed operand
that pointed into the same object.
These checks are currently disabled for the runtime, and can also be
disabled through a new //go:nocheckptr annotation. The latter is
necessary for functions like strings.noescape, which intentionally
violate safety rules to workaround escape analysis limitations.
Fixes#22218.
Change-Id: If5a51273881d93048f74bcff10a3275c9c91da6a
Reviewed-on: https://go-review.googlesource.com/c/go/+/162237
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Keith Randall <khr@golang.org>
Function sizes are computed to determine whether a function
can be kept on one line or should be split to several lines. Part of the
computation is the function header from the FUNC token and until the
opening { token.
Prior to this change, the function header size used distance from the
original source position of the current token, which led to issues when
the source between FUNC and the original source position was rewritten
(such as whitespace being collapsed). Now we take the current output
position into account, so that header size represents the reformatted
source rather than the original source.
The following files in the Go repository are reformatted with this
change:
* strings/strings_test.go
* cmd/compile/internal/gc/fmt.go
In both cases the reformatting is minor and seems to be correct given
the heuristic to single-line functions longer than 100 columns to
multiple lines.
Fixes#28082
Change-Id: Ib737f6933e09b79e83715211421d5262b366ec93
Reviewed-on: https://go-review.googlesource.com/c/go/+/188818
Run-TryBot: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Emmanuel Odeke <emm.odeke@gmail.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This clarifies meaning of "case folding" Unicode equality with more familiar "case insensitive" wording.
For case folding properties see ftp://ftp.unicode.org/Public/UNIDATA/CaseFolding.txt.
Fixes#33447
Change-Id: I6ee85ab398679bf2a0b7d18693985ff0979d6c5a
GitHub-Last-Rev: accc915933
GitHub-Pull-Request: golang/go#34434
Reviewed-on: https://go-review.googlesource.com/c/go/+/196717
Reviewed-by: Rob Pike <r@golang.org>
This is intended to help clear up confusion around the usage of the
Title and ToTitle functions. It includes a link to define title case
to distinguish it from upper case. It also includes an additional
example for the ToTitle function to showcase the difference in behavior
between it and the Title function.
Fixes#33302
Change-Id: I44e62962fb04d0d22966a39eda3a2d16de7a2291
Reviewed-on: https://go-review.googlesource.com/c/go/+/187825
Reviewed-by: Rob Pike <r@golang.org>
Update NewReplacer documentation to specify that in the case of
multiple matches at the same position, the matching old/new
pair that appears first in NewReplacer arguments takes precedence.
Fixes#32699
Change-Id: I9d0616d28e5cd8c9bfa301be201f2b0ebf361dff
Reviewed-on: https://go-review.googlesource.com/c/go/+/185099
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
I have seen code that literally copied the example like this:
if strings.ContainsAny(s, "1 & 2 & 3") {
The developer apparently thought that this is the way to
specify multiple characters and I noticed this pattern
being used in the example. Let's update the example so
that it's clear how multiple Unicode code points should
be specified.
Change-Id: Id4d780555e521af62fb787a7950be1e60848cd95
Reviewed-on: https://go-review.googlesource.com/c/go/+/178737
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The newly added functions create a copy of their input with all bytes in
invalid UTF-8 byte sequences mapped to the UTF-8 byte sequence
given as replacement parameter.
Fixes#25805
Change-Id: Iaf65f65b40c0581c6bb000f1590408d6628321d0
Reviewed-on: https://go-review.googlesource.com/c/go/+/142003
Run-TryBot: Martin Möhrmann <moehrmann@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
When string letters are all in lower/upper cases, both functions respectively
return original string.
Fixes#30987
Change-Id: Ie8d664f7af5e087f82c1bc156933e9a995645bf4
Reviewed-on: https://go-review.googlesource.com/c/go/+/171735
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
CL 56470 unindented bytes.Fields, but not strings.Fields. Do so now to
make it easier to diff the two functions for potential differences.
Change-Id: Ifef81f50cee64e8277e91efa5ec5521d8d21d3bd
Reviewed-on: https://go-review.googlesource.com/c/go/+/170951
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
When I was working on the fix for #31038 (make TrimSpace return nil on
all-space input) I noticed that there were no tests for TrimLeftFunc
and TrimRightFunc, including the funky nil behavior. So add some!
I've just reused the existing TrimFunc test cases for TrimLeftFunc and
TrimRightFunc, as well as adding new tests for the empty string and
all-trimmed cases (which test the nil-returning behavior of TrimFunc and
TrimLeftFunc).
Change-Id: Ib580d4364e9b3c91350305f9d9873080d7862904
Reviewed-on: https://go-review.googlesource.com/c/go/+/170061
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
This change adds a fast path for ASCII strings to both
strings.TrimSpace and bytes.TrimSpace. It doesn't slow down the
non-ASCII path much, if at all.
I added benchmarks for strings.TrimSpace as it didn't have any, and
I fleshed out the benchmarks for bytes.TrimSpace as it just had one
case (for ASCII). The benchmarks (and the code!) are now the same
between the two versions. Below are the benchmark results:
strings.TrimSpace:
name old time/op new time/op delta
TrimSpace/NoTrim-8 18.6ns ± 0% 3.8ns ± 0% -79.53% (p=0.000 n=5+4)
TrimSpace/ASCII-8 33.5ns ± 2% 6.0ns ± 3% -82.05% (p=0.008 n=5+5)
TrimSpace/SomeNonASCII-8 97.1ns ± 1% 88.6ns ± 1% -8.68% (p=0.008 n=5+5)
TrimSpace/JustNonASCII-8 144ns ± 0% 143ns ± 0% ~ (p=0.079 n=4+5)
bytes.TrimSpace:
name old time/op new time/op delta
TrimSpace/NoTrim-8 18.9ns ± 1% 4.1ns ± 1% -78.34% (p=0.008 n=5+5)
TrimSpace/ASCII-8 29.9ns ± 0% 6.3ns ± 1% -79.06% (p=0.008 n=5+5)
TrimSpace/SomeNonASCII-8 91.5ns ± 0% 82.3ns ± 0% -10.03% (p=0.008 n=5+5)
TrimSpace/JustNonASCII-8 150ns ± 0% 150ns ± 0% ~ (all equal)
Fixes#29122
Change-Id: Ica45cd86a219cadf60173ec9db260133cd1d7951
Reviewed-on: https://go-review.googlesource.com/c/go/+/152917
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
There are no empty function declarations in package strings anymore, so
strings.s is no longer needed.
Change-Id: I16fe161a9c06804811e98af0ca074f8f46e2f49d
Reviewed-on: https://go-review.googlesource.com/c/go/+/166458
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Change-Id: I2ff29aa9909be3062fcd5f65af261f5d8c46fbc1
Reviewed-on: https://go-review.googlesource.com/c/153843
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Cleans things up quite a bit.
There's still a few more, like runtime.cmpstring, which might also
be worth fixing.
Change-Id: Ide18dd621efc129cc686db223f47fa0b044b5580
Reviewed-on: https://go-review.googlesource.com/c/148578
Run-TryBot: Keith Randall <khr@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
At each comparison, we're making a copy of the whole string.
Instead, use unsafe to share the string backing store with a []byte.
It reduces the test time from ~4sec to ~1sec on my machine
(darwin/amd64). Some builders were having much more trouble with this
test (>3min), it may help more there.
Fixes#26174Fixes#28573Fixes#26155
Update #26473
Change-Id: Id5856fd26faf6ff46e763a088f039230556a4116
Reviewed-on: https://go-review.googlesource.com/c/147358
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
This lets []byte->string conversions which are used as arguments to
strings.IndexByte and friends have their backing store allocated on
the stack.
It only prevents allocation when the string is small enough (32
bytes), so it isn't perfect. But reusing the []byte backing store
directly requires a bunch more compiler analysis (see #2205 and
related issues).
Fixes#25864.
Change-Id: Ie52430422196e3c91e5529d6e56a8435ced1fc4c
Reviewed-on: https://go-review.googlesource.com/c/146018
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
When an invalid UTF-8 byte sequence is decoded in a range loop over a string
a utf8.RuneError rune is returned. This is not distinguishable from decoding
the valid '\uFFFD' sequence representing utf8.RuneError from a string without
further checks within the range loop.
The previous Map code did not do any extra checks and would thereby not map
invalid UTF-8 byte sequences correctly when those were mapping to utf8.RuneError.
Fix this by adding the extra checks necessary to distinguish the decoding
of invalid utf8 byte sequences from decoding the sequence for utf8.RuneError
when the mapping of a rune is utf8.RuneError.
This fix does not result in a measureable performance regression:
name old time/op new time/op delta
ByteByteMap 1.05µs ± 3% 1.03µs ± 3% ~ (p=0.118 n=10+10)
Map/identity/ASCII 169ns ± 2% 170ns ± 1% ~ (p=0.501 n=9+10)
Map/identity/Greek 298ns ± 1% 303ns ± 4% ~ (p=0.338 n=10+10)
Map/change/ASCII 323ns ± 3% 325ns ± 4% ~ (p=0.679 n=8+10)
Map/change/Greek 628ns ± 5% 635ns ± 1% ~ (p=0.460 n=10+9)
MapNoChanges 120ns ± 4% 119ns ± 1% ~ (p=0.496 n=10+9)
Fixes#26305
Change-Id: I70e99fa244983c5040756fa4549ac1e8cb6022c3
Reviewed-on: https://go-review.googlesource.com/c/131495
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
And start using it elsewhere in the standard library, removing the
copies in the process.
While at it, rewrite the io.WriteString godoc to be more clear, since it
can now make reference to the defined interface.
Fixes#27946.
Change-Id: Id5ba223c09c19e5fb49815bd3b1bd3254fc786f3
Reviewed-on: https://go-review.googlesource.com/c/139457
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
I omitted vendor directories and anything necessary for bootstrapping.
(Tested by bootstrapping with Go 1.4)
Updates #27864
Change-Id: I7d9b68d0372d3a34dee22966cca323513ece7e8a
Reviewed-on: https://go-review.googlesource.com/137856
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
A number of explicit function literals found through the
unlambda linter are removed.
Fixes#26802
Change-Id: I0b122bdd95e9cb804c77efe20483fdf681c8154e
Reviewed-on: https://go-review.googlesource.com/127756
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Joe Tsai
Ignacio Hagopian
David Benjamin
Robert Griesemer
Norman B. Lancaster
Russ Cox
Polina Osadcha
Martin Möhrmann
Praveen Kumar
Alexander Greim
Andy Pan
erifan01
Ian Lance Taylor
Thomas Symborski
po3rin
Brad Fitzpatrick
Matthew Dempsky
Eli Bendersky
Andrew Medvedev
Andrew Todd
Francesco Renzi
Martin Sucha
Максадбек Ахмедов
Tobias Klauser
Ben Hoyt
dupoxy
Keith Randall
沈涛
Keith Randall
Tim Cooper
Ivan Sharavuev
Daniel Martí
Tom Thorogood
Phil Pearl
go101
Johan Brandhorst