Phrases like "returns whether or not the image is opaque" could be
describing what the function does (it always returns, regardless of
the opacity) or what it returns (a boolean indicating the opacity).
Even when the "or not" is missing, the phrasing is bizarre.
Go with "reports whether", which is still clunky but at least makes
it clear we're talking about the return value.
These were edited by hand. A few were cleaned up in other ways.
R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/11699043
This CL provides stable in-place sorting by use of
bottom up merge sort with in-place merging done by
the SymMerge algorithm from P.-S. Kim and A. Kutzner.
The additional space needed for stable sorting (in the form of
stack space) is logarithmic in the inputs size n.
Number of calls to Less and Swap grow like O(n * log n) and
O(n * log n * log n):
Stable sorting random data uses significantly more calls
to Swap than the unstable quicksort implementation (5 times more
on n=100, 10 times more on n=1e4 and 23 times more on n=1e8).
The number of calls to Less is practically the same for Sort and
Stable.
Stable sorting 1 million random integers takes 5 times longer
than using Sort.
BenchmarkSortString1K 50000 328662 ns/op
BenchmarkStableString1K 50000 380231 ns/op 1.15 slower
BenchmarkSortInt1K 50000 157336 ns/op
BenchmarkStableInt1K 50000 191167 ns/op 1.22 slower
BenchmarkSortInt64K 1000 14466297 ns/op
BenchmarkStableInt64K 500 16190266 ns/op 1.12 slower
BenchmarkSort1e2 200000 64923 ns/op
BenchmarkStable1e2 50000 167128 ns/op 2.57 slower
BenchmarkSort1e4 1000 14540613 ns/op
BenchmarkStable1e4 100 58117289 ns/op 4.00 slower
BenchmarkSort1e6 5 2429631508 ns/op
BenchmarkStable1e6 1 12077036952 ns/op 4.97 slower
R=golang-dev, bradfitz, iant, 0xjnml, rsc
CC=golang-dev
https://golang.org/cl/9612044
Demonstrates one way to sort a slice of structs according
to different sort criteria, done in sequence.
One possible answer to a question that comes up often.
R=golang-dev, gri, bradfitz, adg, adg, rogpeppe
CC=golang-dev
https://golang.org/cl/8182044
This avoids an allocation when closures are used
as "macros", in Walk idioms, or as argument to defer.
benchmark old ns/op new ns/op delta
BenchmarkSearchWrappers 1171 354 -69.77%
BenchmarkCallClosure 3 3 -12.54%
BenchmarkCallClosure1 119 7 -93.95%
BenchmarkCallClosure2 183 74 -59.18%
BenchmarkCallClosure3 187 75 -59.57%
BenchmarkCallClosure4 187 76 -58.98%
Compared to Go 1:
benchmark old ns/op new ns/op delta
BenchmarkSearchWrappers 3208 354 -88.97%
Fixes#3520.
R=daniel.morsing, bradfitz, minux.ma, dave, rsc
CC=golang-dev
https://golang.org/cl/7397056
This is based on rsc's code posted to issue 2585.
Benchmark results are greatly improved:
benchmark old ns/op new ns/op delta
BenchmarkSortString1K 564397 445897 -21.00%
BenchmarkSortInt1K 270889 221249 -18.32%
BenchmarkSortInt64K 26850765 21351967 -20.48%
Eyeballing a sampling of the raw number of comparisons shows a drop
on the order of 20-30% almost everywhere. The test input data that
doesn't match that are some of sawtooth/rand/plateau distributions,
where there is no change in the number of comparisons; that is,
there are no situations where this makes *more* comparisons.
Fixes#2585.
R=iant, rsc
CC=golang-dev
https://golang.org/cl/7306098
It was well-defined but easy to miss that the return value for
"not found" is len(input) not -1 as many expect.
Fixes#4205.
R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/6820080
Let's tell the world that Go's sort is O(n log n).
Surely this is a feature we intend to keep.
R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/5867045
They looked out of place in godoc.
Includes documenting sort stability.
Fixes#3356
R=golang-dev, gri, trolleriprofessorn
CC=golang-dev
https://golang.org/cl/5855044
go/doc: move Examples to go/ast
cmd/go: use go/doc to read examples
src/pkg: update examples to use new convention
This is to make whole file examples more readable. When presented as a
complete function, preceding an Example with its output is confusing.
The new convention is to put the expected output in the final comment
of the example, preceded by the string "output:" (case insensitive).
An idiomatic example looks like this:
// This example demonstrates Foo by doing bar and quux.
func ExampleFoo() {
// example body that does bar and quux
// Output:
// example output
}
R=rsc, gri
CC=golang-dev
https://golang.org/cl/5673053
Consequently, remove many package Makefiles,
and shorten the few that remain.
gomake becomes 'go tool make'.
Turn off test phases of run.bash that do not work,
flagged with $BROKEN. Future CLs will restore these,
but this seemed like a big enough CL already.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5601057
- no empty lines inside empty structs and interfaces
- top-level declarations are separated by a blank line if
a) they are of different kind (e.g. const vs type); or
b) there are documentation comments associated with a
declaration (this is new)
- applied gofmt -w misc src
The actual changes are in go/printer/nodes.go:397-400 (empty structs/interfaces),
and go/printer/printer.go:307-309 (extra line break). The remaining
changes are cleanups w/o changing the existing functionality.
Fixes issue 2570.
R=rsc
CC=golang-dev
https://golang.org/cl/5493057
This CL introduces the go.Example type and go.Examples functions that
are used to represent and extract code samples from Go source.
They should be of the form:
// Output of this function.
func ExampleFoo() {
fmt.Println("Output of this function.")
}
It also modifies godoc to read example code from _test.go files,
and include them in the HTML output with JavaScript-driven toggles.
It also implements testing of example functions with gotest.
The stdout/stderr is compared against the output comment on the
function.
This CL includes examples for the sort.Ints function and the
sort.SortInts type. After patching this CL in and re-building go/doc
and godoc, try
godoc -http=localhost:6060
and visit http://localhost:6060/pkg/sort/
R=gri, r, rsc
CC=golang-dev
https://golang.org/cl/5137041
Previously comparisons with NaN led to contradictory results if it was
compared to anything not NaN, since Less always returned false, thus
breaking monotonicity of ordering.
This fix makes NaN less than anything else and adds NaN and (+-)Inf to
testcases.
Fixes#2092.
R=golang-dev, r, rsc, r
CC=golang-dev
https://golang.org/cl/4805051
Doing the tail recursion elimination explicitly
seems safer than leaving it to the compiler;
the code is still clean and easy to understand.
R=r, r2, gri
CC=golang-dev
https://golang.org/cl/3373041
Backwards incompatible change, but makes
it easier to reason about non-idiomatic searches:
now f specifies what is sought.
R=gri
CC=golang-dev
https://golang.org/cl/3195042
Change comment to be more generic,
with indexed data structure search as
one common use case.
Fix typo []data.
R=gri, rog
CC=golang-dev
https://golang.org/cl/3159041
