When scanning input and "white space" is permitted, a carriage return
followed immediately by a newline (\r\n) is treated exactly the same
as a plain newline (\n). I hope this makes it work better on Windows.
We do it everywhere, not just on Windows, since why not?
Fixes#5391.
R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/12142043
The old code put the index before the period in the precision;
it should be after so it's always before the star, as documented.
A little trickier to do in one pass but compensated for by more
tests and catching a couple of other error cases.
R=rsc
CC=golang-dev
https://golang.org/cl/9751044
This text is added to doc.go:
Explicit argument indexes:
In Printf, Sprintf, and Fprintf, the default behavior is for each
formatting verb to format successive arguments passed in the call.
However, the notation [n] immediately before the verb indicates that the
nth one-indexed argument is to be formatted instead. The same notation
before a '*' for a width or precision selects the argument index holding
the value. After processing a bracketed expression [n], arguments n+1,
n+2, etc. will be processed unless otherwise directed.
For example,
fmt.Sprintf("%[2]d %[1]d\n", 11, 22)
will yield "22, 11", while
fmt.Sprintf("%[3]*[2].*[1]f", 12.0, 2, 6),
equivalent to
fmt.Sprintf("%6.2f", 12.0),
will yield " 12.00". Because an explicit index affects subsequent verbs,
this notation can be used to print the same values multiple times
by resetting the index for the first argument to be repeated:
fmt.Sprintf("%d %d %#[1]x %#x", 16, 17)
will yield "16 17 0x10 0x11".
The notation chosen differs from that in C, but I believe it's easier to read
and to remember (we're indexing the arguments), and compatibility with
C's printf was never a strong goal anyway.
While we're here, change the word "field" to "arg" or "argument" in the
code; it was being misused and was confusing.
R=rsc, bradfitz, rogpeppe, minux.ma, peter.armitage
CC=golang-dev
https://golang.org/cl/9680043
Better explanation of width for floating-point values.
Explain that scanning does not handle %#q etc.
Fixes#4202.
Fixes#4206.
R=golang-dev, adg, rsc, iant
CC=golang-dev
https://golang.org/cl/6620074
This is a slight change to fmt's semantics, but means that if you use
%d to print an integer with a Stringable value, it will print as an integer.
This came up because Time.Month() couldn't cleanly print as an integer
rather than a name. Using %d on Stringables is silly anyway, so there
should be no effect outside the fmt tests.
As a mild bonus, certain recursive failures of String methods
will also be avoided this way.
R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/5453053
Handling os.Error is no different than handling fmt.Stringer
here, so the code is redundant now, but it will be necessary
once error goes in.
Adding it now will make gofix fix it.
R=r
CC=golang-dev
https://golang.org/cl/5331045
%+q uses strconv.Quote[Rune]ToASCII, guaranteeing ASCII-only output.
%#U a quoted character if the rune is printable: 'x'=U+0078; otherwise
it's as before: U+000A.
R=golang-dev, gri, rsc
CC=golang-dev
https://golang.org/cl/4589047
Add a new Read method to ScanState so that it
satisfies the io.Reader interface; rename
Getrune and Ungetrune to ReadRune and UnreadRune.
Make sure ReadRune does not read past width restrictions;
remove now-unnecessary Width method from ScanState.
Also make the documentation a little clearer as to
how ReadRune and UnreadRune are used.
R=r, r2
CC=golang-dev
https://golang.org/cl/4240056
signed or unsigned integers using %v or the formatless scanner.
That is, Sscan("0x11", &i) or Sscanf("0x11", "%v", &i) will now
set i to 17. If a format other than %v is presented, the behavior
is as before.
Fixes#1469.
R=rsc
CC=golang-dev
https://golang.org/cl/4131042
fmt.Printf("%U", 1) yields "U+0001"
It's essentially "U+%.4x" but lets you override the precision works in scan, too.
R=rsc
CC=golang-dev
https://golang.org/cl/3423043
