This shortens, simplifies and regularizes the code significantly.
(Improvements to reflect could make another step.)
Passes all.bash.
One semantic change occurs: The String() method changes
behavior. It used to run only for string formats such as %s and %q.
Instead, it now runs whenever the item has the method and the
result is then processed by the format as a string. Besides the
regularization, this has three effects:
1) width is honored for String() items
2) %x works for String() items
3) implementations of String that merely recur will recur forever
Regarding point 3, example from the updated documentation:
type X int
func (x X) String() string { return Sprintf("%d", x) }
should cast the value before recurring:
func (x X) String() string { return Sprintf("%d", int(x)) }
R=rsc
CC=golang-dev
https://golang.org/cl/1613045
fmt.Printf("%b", int8(-1)) prints 64 ones instead of 8.
This happens only for signed integers (int8, in16 and int32). I guess it's because of the way the conversion between integer types works. From go spec: "Conversions between integer types. If the value is a signed quantity, it is sign extended to implicit infinite precision ....". And there are several conversions to int64 and uint64 in the fmt package. This pathch solves only half of the problem. On a 32 bit system, an fmt.Printf("%b", int(-1)) should still print 64 ones.
R=golang-dev, r
CC=golang-dev
https://golang.org/cl/891049
parsing and printing to new syntax.
Use -oldparser to parse the old syntax,
use -oldprinter to print the old syntax.
2) Change default gofmt formatting settings
to use tabs for indentation only and to use
spaces for alignment. This will make the code
alignment insensitive to an editor's tabwidth.
Use -spaces=false to use tabs for alignment.
3) Manually changed src/exp/parser/parser_test.go
so that it doesn't try to parse the parser's
source files using the old syntax (they have
new syntax now).
4) gofmt -w src misc test/bench
2nd set of files.
R=rsc
CC=golang-dev
https://golang.org/cl/179067
Roughly 33% faster for simple cases, probably more for complex ones.
Before:
mallocs per Sprintf(""): 4
mallocs per Sprintf("xxx"): 6
mallocs per Sprintf("%x"): 10
mallocs per Sprintf("%x %x"): 12
Now:
mallocs per Sprintf(""): 2
mallocs per Sprintf("xxx"): 3
mallocs per Sprintf("%x"): 5
mallocs per Sprintf("%x %x"): 7
Speed improves because of avoiding mallocs and also by sharing a bytes.Buffer
between print.go and format.go rather than copying the data back after each
printed item.
Before:
fmt_test.BenchmarkSprintfEmpty 1000000 1346 ns/op
fmt_test.BenchmarkSprintfString 500000 3461 ns/op
fmt_test.BenchmarkSprintfInt 500000 3671 ns/op
Now:
fmt_test.BenchmarkSprintfEmpty 2000000 995 ns/op
fmt_test.BenchmarkSprintfString 1000000 2745 ns/op
fmt_test.BenchmarkSprintfInt 1000000 2391 ns/op
fmt_test.BenchmarkSprintfIntInt 500000 3751 ns/op
I believe there is more to get but this is a good milestone.
R=rsc
CC=golang-dev, hong
https://golang.org/cl/166076
- enabled for function declarations (not just function literals)
- applied gofmt -w $GOROOT/src
(look for instance at src/pkg/debug/elf/elf.go)
R=r, rsc
CC=go-dev
http://go/go-review/1026006
