Check for and call the special printing and format methods such as String
at printing depth 0 when printing the concrete value of a reflect.Value.
Fixes: #16015
Change-Id: I23bd2927255b60924e5558321e98dd4a95e11c4c
Reviewed-on: https://go-review.googlesource.com/30753
Reviewed-by: Russ Cox <rsc@golang.org>
Run-TryBot: Martin Möhrmann <martisch@uos.de>
TryBot-Result: Gobot Gobot <gobot@golang.org>
It's the same as %#x not %x.
Just a documentation change; tests already cover it.
Fixes#17322
Change-Id: Ia9db229f781f9042ac5c0bb824e3d7a26fb74ec5
Reviewed-on: https://go-review.googlesource.com/31254
Reviewed-by: Russ Cox <rsc@golang.org>
This CL makes minor adjustment to the handling of spaces and newlines
and then documents the result.
The semantic adjustment mainly concerns the handling of a run of
spaces following a newline in the format, like in "\n ".
Previously, that run of spaces was ignored entirely, leading to paradoxes
like the format "1 \n 2" not matching itself as input.
Now, spaces following a newline in the format match zero or more
spaces following the corresponding newline in the input.
The changes to the test suite show how minor the semantic adjustments are
and how they make the behavior more regular than previously.
This CL also updates the documentation to explain the handling of
spaces more precisely, incorporating the draft from CL 17723 but
describing the newly introduced behavior.
Fixes#13565.
Change-Id: I129666e9ba42de3c28b67f75cb47488e9a4c1867
Reviewed-on: https://go-review.googlesource.com/30611
Reviewed-by: Rob Pike <r@golang.org>
There are no semantic changes here, just tests to establish
the status quo. A followup CL will make some semantic changes,
the (limited) scope of which should be clear from the number of
tests that change.
For #13565.
Change-Id: I960749cf59d4dfe39c324875bcc575096654f883
Reviewed-on: https://go-review.googlesource.com/30610
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
It is better to document what golang does, rather than how it differs
from languages which readers may or may not know.
That the output format is based on the type is basically self-evident
if you consider this just in go terms.
Change-Id: I0223e9b4cb67cc83a9ebe4d424e6c151d7ed600f
Reviewed-on: https://go-review.googlesource.com/28393
Reviewed-by: Rob Pike <r@golang.org>
Change https://golang.org/cl/19895 caused a regression
where the last character in a string would be dropped if it was
accompanied by an io.EOF.
This change fixes the logic so that the last byte is still returned
without a problem.
Fixes#16393
Change-Id: I7a4d0abf761c2c15454136a79e065fe002d736ea
Reviewed-on: https://go-review.googlesource.com/24981
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Ignore the f.zero flag and use spaces for padding instead
when precision is set.
Fixes#15331
Change-Id: I3ac485df24b7bdf4fddf69e3cc17c213c737b5ff
Reviewed-on: https://go-review.googlesource.com/22131
Run-TryBot: Rob Pike <r@golang.org>
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Reviewed-by: Rob Pike <r@golang.org>
This code made sense before fmt switched to using sync.Pool, but a
sync.Pool clears all items on GC, so not reusing something based on
size is just a waste of memory.
Change-Id: I201312b0ee6c572ff3c0ffaf71e42623a160d23f
Reviewed-on: https://go-review.googlesource.com/21480
Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Simplify the handling of zero padding in fmt_integer and
fmt_float to not require any adjustment of the format flags.
Note that f.zero can only be true when padding to the left
and f.wid is always greater than or equal to 0.
Change-Id: I204b57d103c0eac13d86995992f2b26209196925
Reviewed-on: https://go-review.googlesource.com/21185
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Make verbs b,c,o and U work for any array and slice of integer
type including byte and uint8.
Fix a bug that triggers badverb for []uint8 and []byte type
on the slice/array level instead of on each element like for
any other slice or array type.
Add tests that make sure we do not accidentally alter the
behavior of printing []byte for []byte and []uint8 type
if they are used at the top level when formatting with %#v.
name old time/op new time/op delta
SprintfHexBytes-2 177ns ± 2% 176ns ± 2% ~ (p=0.066 n=48+49)
SprintfBytes-2 330ns ± 1% 329ns ± 1% ~ (p=0.118 n=45+47)
Fixes#13478
Change-Id: I99328a184973ae219bcc0f69c3978cb1ff462888
Reviewed-on: https://go-review.googlesource.com/20686
Run-TryBot: Rob Pike <r@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Merge printReflectValue into printValue. Determine if handleMethods
was already called in printArg by checking if depth is 0. Do not
call handleMethods on depth 0 again in printValue to not introduce
a performance regression. handleMethods is called already in printArg
to not introduce a performance penalty for top-level Stringer,
GoStringer, Errors and Formatters by using reflect.ValueOf on them
just to retrieve them again as interface{} values in printValue.
Clear p.arg in printValue after handleMethods to print the type
of the value inside the reflect.Value when a bad verb is encountered
on the top level instead of printing "reflect.Value=" as the type of
the argument. This also fixes a bug that incorrectly prints the
whole map instead of just the value for a key if the returned value
by the map for the key is an invalid reflect value.
name old time/op new time/op delta
SprintfPadding-2 229ns ± 2% 227ns ± 1% -0.50% (p=0.013 n=20+20)
SprintfEmpty-2 36.4ns ± 6% 37.2ns ±14% ~ (p=0.091 n=18+20)
SprintfString-2 102ns ± 1% 102ns ± 0% ~ (p=0.751 n=20+20)
SprintfTruncateString-2 142ns ± 0% 141ns ± 1% -0.95% (p=0.000 n=16+20)
SprintfQuoteString-2 389ns ± 0% 388ns ± 0% -0.12% (p=0.019 n=20+20)
SprintfInt-2 100ns ± 2% 100ns ± 1% ~ (p=0.188 n=20+15)
SprintfIntInt-2 155ns ± 3% 154ns ± 2% ~ (p=0.092 n=20+20)
SprintfPrefixedInt-2 250ns ± 2% 251ns ± 3% ~ (p=0.559 n=20+20)
SprintfFloat-2 177ns ± 2% 175ns ± 1% -1.30% (p=0.000 n=20+20)
SprintfComplex-2 516ns ± 1% 510ns ± 1% -1.13% (p=0.000 n=19+16)
SprintfBoolean-2 90.9ns ± 3% 90.6ns ± 1% ~ (p=0.193 n=19+19)
SprintfHexString-2 171ns ± 1% 169ns ± 1% -1.44% (p=0.000 n=19+20)
SprintfHexBytes-2 180ns ± 1% 180ns ± 1% ~ (p=0.060 n=19+18)
SprintfBytes-2 330ns ± 1% 329ns ± 1% -0.42% (p=0.003 n=20+20)
SprintfStringer-2 354ns ± 3% 352ns ± 3% ~ (p=0.525 n=20+19)
SprintfStructure-2 804ns ± 3% 776ns ± 2% -3.56% (p=0.000 n=20+20)
FprintInt-2 155ns ± 0% 151ns ± 1% -2.35% (p=0.000 n=19+20)
FprintfBytes-2 169ns ± 0% 170ns ± 1% +0.81% (p=0.000 n=18+19)
FprintIntNoAlloc-2 112ns ± 0% 109ns ± 1% -2.28% (p=0.000 n=20+20)
Change-Id: Ib9a39082ed1be0f1f7499ee6fb6c9530f043e43a
Reviewed-on: https://go-review.googlesource.com/20923
Run-TryBot: Rob Pike <r@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Remove format flag reset from doPrint. Flags will not be set in
doPrint and printArg will not return with flags modified.
Remove the extra arguments addspace and addnewline and split up
doPrint into two simpler and specialized functions.
Change-Id: Ib884d027abfbb31c6f01b008f51d6d76fc0c1a17
Reviewed-on: https://go-review.googlesource.com/21181
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Deduplicate the verb switch for signed and unsigned integer formatting.
Make names of integer related functions consistent
with names of other fmt functions.
Consolidate basic integer tests.
Change-Id: I0c19c24f1c2c06a3b1a4d7d377dcdac3b36bb0f5
Reviewed-on: https://go-review.googlesource.com/20831
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Changes the integer function to restore the original f.zero value
and therefore padding type before returning.
Change-Id: I456449259a3d39bd6d62e110553120c31ec63f23
Reviewed-on: https://go-review.googlesource.com/20512
Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
handleMethods can format Error() and String() directly as its known
these return strings that can be directly printed using fmtString.
Remove the obsolete depth argument from handleMethods.
Remove the depth argument from printArg since it is only ever
called with depth set to 0. Recursion for formatting complex
arguments is handled only by printValue which keeps track of depth.
Change-Id: I4c4be588751de12ed999e7561a51bc168eb9eb2d
Reviewed-on: https://go-review.googlesource.com/20911
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Remove rewriting of flags before calling formatters.
Change Flag method to directly take plusV and sharpV flags
into account when reporting if plus or sharp flag is set.
Change-Id: Ic3423881ad89e5a5f9fff5ab59e842062394ef6d
Reviewed-on: https://go-review.googlesource.com/20859
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Separate unicode formatting into its own fmt_unicode function.
Remove the fmtUnicode wrapper and the f.unicode and f.uniQuote
flags that are not needed anymore. Remove mangling and restoring
of the precision and sharp flags.
Removes the buffer copy needed for %#U by moving
the character encoding before the number encoding.
Changes the behavior of plus and space flag to have
no effect instead of printing a plus or space before "U+".
Always print at least four digits after "U+"
even if precision is set to less than 4.
Change-Id: If9a0ee79e9eca2c76f06a4e0fdd75d98393899ac
Reviewed-on: https://go-review.googlesource.com/20574
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Use The fmt internal buffer for character formatting instead of
the pp Printer rune decoding buffer.
Uses an uint64 instead of int64 argument to fmt_c and fmt_qc for easier
range checks since no valid runes are represented by negative numbers or
are above 0x10ffff.
Add range checks to fmt_c and fmt_qc to guarantee that a RuneError
character is returned by the functions for any invalid code point
in range uint64. For invalid code points in range utf8.MaxRune
the used utf8 and strconv functions already return a RuneError.
Change-Id: I9772f804dfcd79c3826fa7f6c5ebfbf4b5304a51
Reviewed-on: https://go-review.googlesource.com/20373
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Remove check for %p and %T in printValue.
These verbs are not recursive and are handled already in
printArg which is called on any argument before printValue.
Format the type string for %T directly instead of invoking
the more complex printArg with %s on the type string.
Decouple the %T tests from variables declared in scan_test.go.
Change-Id: Ibd51566bd4cc1a260ce6d052f36382ed05020b48
Reviewed-on: https://go-review.googlesource.com/20622
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Do a reset of the fmt flags before printing the extra argument
error message to prevent a malformed printing of extra arguments.
Regroup tests for extra argument error strings.
Change-Id: Ifd97f5ca36f6c97ed5a380d975cf154d17997d3f
Reviewed-on: https://go-review.googlesource.com/20571
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Use constants instead of dynamically computed values to determine
the bit sizes of types similar to how strconv and other packages
directly compute these sizes. Move these constants near the code
that uses them.
Change-Id: I78d113b7e697466097e32653975df5990380c2c1
Reviewed-on: https://go-review.googlesource.com/20514
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Treat the verb %X in the same special way as %q, %s and %x
are for arrays and slices with byte type elements.
Modify input for tests so the result of %x and %X is distinct.
Change-Id: I38d227755e98c7fad5e4adc2f603c6873aa910fd
Reviewed-on: https://go-review.googlesource.com/20516
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Uses a switch statement for direct format function selection
similar to other types verb handling in fmt.
Applies padding also to nil pointers formatted with %v.
Guards against "slice bounds out of range" panic in TestSprintf
when a pointer test results in a formatted string s
that is shorter than the index i the pointer should appear in.
Adds more and rearranges tests.
Fixes#14712Fixes#14714
Change-Id: Iaf5ae37b7e6ba7d27d528d199f2b2eb9d5829b8c
Reviewed-on: https://go-review.googlesource.com/20371
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Removes specialized functions for each verb and float/complex size
and replaces them with generic variants fmtFloat and
fmtComplex similar to other generic fmt functions.
Simplifies the complex formatting by relying on fmtFloat
to handle the verb and default precision selection.
Complex imaginary formatting does not need to clear the f.space flag
because the set f.plus flag will force a sign instead of a space.
Sets default precision for %b to -1 (same as %g and %G)
since precision for %b has no affect in strconv.AppendFloat.
Add more tests and group them a bit better.
Use local copies of +Inf,-Inf and NaN instead
of math package functions for testing.
Saves around 8kb in the go binary.
name old time/op new time/op delta
SprintfFloat-2 200ns ± 4% 196ns ± 4% -1.55% (p=0.007 n=20+20)
SprintfComplex-2 569ns ± 4% 570ns ± 3% ~ (p=0.804 n=20+20)
Change-Id: I36d35dab6f835fc2bd2c042ac97705868eb2446f
Reviewed-on: https://go-review.googlesource.com/20252
Reviewed-by: Rob Pike <r@golang.org>
Run-TryBot: Rob Pike <r@golang.org>
Reuse the internal buffer and use append versions of
the strconv quote functions to avoid some allocations.
Add more tests.
name old time/op new time/op delta
SprintfQuoteString-2 486ns ± 2% 416ns ± 2% -14.42% (p=0.000 n=20+20)
name old allocs/op new allocs/op delta
SprintfQuoteString-2 4.00 ± 0% 2.00 ± 0% -50.00% (p=0.000 n=20+20)
Change-Id: I63795b51fd95c53c5993ec8e6e99b659941f9f54
Reviewed-on: https://go-review.googlesource.com/20251
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Instead of calling printArg in fmtBytes to format each byte call
the byte formatting functions directly since it is known each
element is of type byte.
Add more tests for byte slice and array formatting.
name old time/op new time/op delta
SprintfBytes-2 843ns ±16% 417ns ±11% -50.58% (p=0.000 n=20+20)
Change-Id: I5b907dbf52091e3de9710b09d67649c76f4c17e9
Reviewed-on: https://go-review.googlesource.com/20176
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
formatFloat should restore the original f.wid value before
returning. Callers should not have to save and restore f.wid.
Fixes: #14642
Change-Id: I531dae15c7997fe8909e2ad1ef7c376654afb030
Reviewed-on: https://go-review.googlesource.com/20179
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
No extra buffering is needed to save the encoding
since the left padding can be computed and written out
before the encoding is generated.
Add extra tests to both string and byte slice formatting.
name old time/op new time/op delta
SprintfHexString-2 410ns ± 3% 194ns ± 3% -52.60% (p=0.000 n=20+19)
SprintfHexBytes-2 431ns ± 3% 202ns ± 2% -53.13% (p=0.000 n=18+20)
Change-Id: Ibca4316427c89f834e4faee61614493c7eedb42b
Reviewed-on: https://go-review.googlesource.com/20097
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Count only the runes up to the requested precision
to decide where to truncate a string.
Change the loop within truncate to need fewer jumps.
name old time/op new time/op delta
SprintfTruncateString-2 188ns ± 3% 155ns ± 3% -17.43% (p=0.000 n=20+20)
Change-Id: I17ca9fc0bb8bf7648599df48e4785251bbc31e99
Reviewed-on: https://go-review.googlesource.com/20098
Reviewed-by: Rob Pike <r@golang.org>
The tree's pretty inconsistent about single space vs double space
after a period in documentation. Make it consistently a single space,
per earlier decisions. This means contributors won't be confused by
misleading precedence.
This CL doesn't use go/doc to parse. It only addresses // comments.
It was generated with:
$ perl -i -npe 's,^(\s*// .+[a-z]\.) +([A-Z]),$1 $2,' $(git grep -l -E '^\s*//(.+\.) +([A-Z])')
$ go test go/doc -update
Change-Id: Iccdb99c37c797ef1f804a94b22ba5ee4b500c4f7
Reviewed-on: https://go-review.googlesource.com/20022
Reviewed-by: Rob Pike <r@golang.org>
Reviewed-by: Dave Day <djd@golang.org>
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This is a subset of https://golang.org/cl/20022 with only the copyright
header lines, so the next CL will be smaller and more reviewable.
Go policy has been single space after periods in comments for some time.
The copyright header template at:
https://golang.org/doc/contribute.html#copyright
also uses a single space.
Make them all consistent.
Change-Id: Icc26c6b8495c3820da6b171ca96a74701b4a01b0
Reviewed-on: https://go-review.googlesource.com/20111
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Use only reflect.TypeOf to detect if argument is a string.
The wasString return is only needed in doPrint with the 'v' verb.
This type of string detection is handled correctly by reflect.TypeOf
which is used already in doPrint for identifying a string argument.
Remove now obsolete wasString computations and return values.
Change-Id: Iea2de7ac0f5c536a53eec63f7e679d628f5af8dc
Reviewed-on: https://go-review.googlesource.com/19976
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Named returned values should only be used on public funcs and methods
when it contributes to the documentation.
Named return values should not be used if they're only saving the
programmer a few lines of code inside the body of the function,
especially if that means there's stutter in the documentation or it
was only there so the programmer could use a naked return
statement. (Naked returns should not be used except in very small
functions)
This change is a manual audit & cleanup of public func signatures.
Signatures were not changed if:
* the func was private (wouldn't be in public godoc)
* the documentation referenced it
* the named return value was an interesting name. (i.e. it wasn't
simply stutter, repeating the name of the type)
There should be no changes in behavior. (At least: none intended)
Change-Id: I3472ef49619678fe786e5e0994bdf2d9de76d109
Reviewed-on: https://go-review.googlesource.com/20024
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Andrew Gerrand <adg@golang.org>
Do not replace the sign in front of a number with a space if both
f.space and f.plus are both specified for number formatting.
This was already the case for integers but not for floats
and complex numbers.
Updates: #14543.
Change-Id: I07ddeb505003db84a8a7d2c743dc19fc427a00bd
Reviewed-on: https://go-review.googlesource.com/19974
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Once upon a time fmt did use bytes.Buffer for its buffer.
The buffer write methods still mimic the bytes.Buffer signatures.
The current code depends on manipulating the buffer []bytes array directly
which makes going back to bytes.Buffer by only changing the type of buffer
impossible. Since type buffer is not exported the methods can be simplified
to the needs of fmt. This saves space and avoids unnecessary overhead.
Use WriteString instead of Write for known inputs since
WriteString is faster than Write to append the same data.
This also saves space in the binary.
Remove the add method from Printer and depending on the data to be written
use WriteRune or WriteByte directly instead.
In total makes the go binary around 4 kilobyte smaller.
name old time/op new time/op delta
SprintfEmpty-2 24.1ns ± 3% 23.8ns ± 1% -1.14% (p=0.000 n=20+20)
SprintfString-2 114ns ± 2% 114ns ± 4% ~ (p=0.558 n=20+19)
SprintfInt-2 116ns ± 9% 118ns ± 7% ~ (p=0.086 n=20+20)
SprintfIntInt-2 195ns ± 6% 193ns ± 5% ~ (p=0.345 n=20+19)
SprintfPrefixedInt-2 251ns ±16% 241ns ± 9% -3.69% (p=0.024 n=20+19)
SprintfFloat-2 203ns ± 4% 205ns ± 5% ~ (p=0.153 n=20+20)
SprintfBoolean-2 101ns ± 7% 96ns ±11% -5.23% (p=0.005 n=19+20)
ManyArgs-2 651ns ± 7% 628ns ± 7% -3.44% (p=0.002 n=20+20)
FprintInt-2 164ns ± 2% 158ns ± 2% -3.62% (p=0.000 n=20+18)
FprintfBytes-2 215ns ± 1% 216ns ± 1% +0.58% (p=0.000 n=20+20)
FprintIntNoAlloc-2 115ns ± 0% 112ns ± 0% -2.61% (p=0.000 n=20+20)
ScanInts-2 700µs ± 0% 702µs ± 1% +0.38% (p=0.000 n=18+20)
ScanRecursiveInt-2 82.7ms ± 0% 82.7ms ± 0% ~ (p=0.820 n=20+20)
Change-Id: I0409eb170b8a26d9f4eb271f6292e5d39faf2d8b
Reviewed-on: https://go-review.googlesource.com/19955
Reviewed-by: Rob Pike <r@golang.org>
Move the decision if zero padding is allowed to doPrintf
where the other formatting decisions are made.
Removes some dead code for negative f.wid that was never used
due to f.wid always being positive and f.minus deciding if left
or right padding should be used.
New padding code writes directly into the buffer and is as fast
as the old version but avoids the cost of needing package init.
name old time/op new time/op delta
SprintfPadding-2 246ns ± 5% 245ns ± 4% ~ (p=0.345 n=50+47)
Change-Id: I7dfddbac8e328f4ef0cdee8fafc0d06c784b2711
Reviewed-on: https://go-review.googlesource.com/19957
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
All io.Reader that are passed to newScanState in all the standard
library tests that implement io.RuneReader also implement io.RuneScanner.
Do not check on each call ScanState's UnreadRune that the used RuneReader
also implements the UnreadRune method by using a private interface.
Instead require the used Reader to implement the public RuneScanner
interface.
The extra implementation logic for UnreadRune is removed from ScanState.
Instead the readRune wrapper is extended to implement UnreadRune for the
RuneScanner interface. If the Reader passed to newScanstate does not
implement RuneScanner the readRune wrapper is used to implement the
missing functionality.
Note that a RuneReader that does not implement RuneScanner will also
be wrapped by runeRead which was not the case before.
Performance with the readRune wrapper is better than without before.
Add benchmark to compare performance with and without using the
readRune wrapper.
name old time/op new time/op delta
ScanInts-2 704µs ± 0% 615µs ± 1% -12.73% (p=0.000 n=20+20)
ScanRecursiveInt-2 82.6ms ± 0% 51.4ms ± 0% -37.71% (p=0.000 n=20+20)
ScanRecursiveIntReaderWrapper-2 85.1ms ± 0% 52.4ms ± 0% -38.36% (p=0.000 n=20+20)
Change-Id: I8c6e85db9b87a8171caab12f020b6e256b498e81
Reviewed-on: https://go-review.googlesource.com/19895
Run-TryBot: Rob Pike <r@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
Martin Möhrmann
Odin Ugedal
Brad Fitzpatrick
Russ Cox
Martin Möhrmann
Rob Pike
Oleg Vakheta
Jim Kingdon
Joe Tsai
Mohit Agarwal
Emmanuel Odeke
Dominik Honnef