Since Reader.Peek potentially reads from the underlying io.Reader,
discarding previous buffers, UnreadRune and UnreadByte cannot
necessarily work. Change Peek to invalidate the unread buffers in all
cases (as allowed according to the documentation) and thus prevent
hiding bugs in the caller.
(This change was previoiusly merged and then reverted due concern about
being too close to a release)
Fixes#18556
Change-Id: I9027d75aa834d4b27703f37711ba25de04d89f3c
GitHub-Last-Rev: 917ef1e511
GitHub-Pull-Request: golang/go#28768
Reviewed-on: https://go-review.googlesource.com/c/149297
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
CL 145577 added the part about io.ReadFull to read len(p)
but it should be next to the existing sentence about not
reading len(p) bytes.
Change-Id: Idfa037c59a3085d44d5da6129188473db0e96d23
Reviewed-on: https://go-review.googlesource.com/c/148903
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Alan Donovan <adonovan@google.com>
Many times when using bufio.Reader I imagine, incorrectly, that it
implements the retry loop itself, being a high-level buffered wrapper
around, say, a file descriptor prone to short reads. This comment
would have saved me much time.
Change-Id: I34c790e0d7c1515430a76d02ce4739b586a36ba7
Reviewed-on: https://go-review.googlesource.com/c/145577
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Rob Pike <r@golang.org>
When existing data in buffer does not have delimiter,
and new data is added with b.fill(), continue search from
previous point instead of starting from beginning.
Change-Id: Id78332afe2b0281b4a3c86bd1ffe9449cfea7848
GitHub-Last-Rev: 08e7d2f501
GitHub-Pull-Request: golang/go#25441
Reviewed-on: https://go-review.googlesource.com/113535
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
All the readers are denoted as `b` while for `Reader.Size()` it is `r`.
Change-Id: Ib6f97306c11b3abb2ff30edbc9f9362cad36d080
GitHub-Last-Rev: 992f88b374
GitHub-Pull-Request: golang/go#26205
Reviewed-on: https://go-review.googlesource.com/122156
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
In general use of these magic methods must be documented so that
users understand what will happen.
Fixes#23289
Change-Id: Ic46915eee1d3b7e57d8d1886834ddfb2e8e66e62
Reviewed-on: https://go-review.googlesource.com/103238
Reviewed-by: Rob Pike <r@golang.org>
Go 1.9 beta 2 is already out.
It's too late to break code with a change like this.
This can be rolled forward for Go 1.10.
This reverts commit ae238688d2.
Change-Id: Ib67b8629e3deac5d50d76581aba6a91ca7a7853e
Reviewed-on: https://go-review.googlesource.com/47570
Reviewed-by: Russ Cox <rsc@golang.org>
Since Reader.Peek potentially reads from the underlying io.Reader,
discarding previous buffers, UnreadRune and UnreadByte cannot
necessarily work. Change Peek to invalidate the unread buffers in all
cases (as allowed according to the documentation) and thus prevent
hiding bugs in the caller.
Fixes#18556
Change-Id: I8d836db7ce31c4aaecb4f61c24573b0332bbf30d
Reviewed-on: https://go-review.googlesource.com/46850
Reviewed-by: Robert Griesemer <gri@golang.org>
Done with grep & interactive search & replace, to double-check
replacements. Not many remained after CL 20022.
Fixes#18572
Change-Id: Idbe90ba3b584f9b9661d2bbd141607daaadfa41a
Reviewed-on: https://go-review.googlesource.com/45270
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Returns at the end of func bodies where the funcs have no return values
are pointless.
Change-Id: I0da5ea78671503e41a9f56dd770df8c919310ce5
Reviewed-on: https://go-review.googlesource.com/41093
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
After resizing the scan buffer, we can immediately read into the
newly-resized buffer since we know there is now space.
Fixes#15712.
Change-Id: I56fcfaeb67045ee753a012c37883aa7c81b6e877
Reviewed-on: https://go-review.googlesource.com/31715
Run-TryBot: Quentin Smith <quentin@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Russ Cox <rsc@golang.org>
CL/19862 (f79b50b8d5) recently introduced the constants
SeekStart, SeekCurrent, and SeekEnd to the io package. We should use these constants
consistently throughout the code base.
Updates #15269
Change-Id: If7fcaca7676e4a51f588528f5ced28220d9639a2
Reviewed-on: https://go-review.googlesource.com/22097
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Joe Tsai <joetsai@digital-static.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>
The existing implementation returns nil, ErrBufferFull when n > len(b.buf),
now it will return any data in the buffer and ErrBufferFull.
Fixes#14121
Change-Id: Ie52d32ccd80e4078ebfae6e75393c89675959ead
Reviewed-on: https://go-review.googlesource.com/19091
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Robert Griesemer <gri@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>
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>
Or at least make them true.
Fixes#12237.
Change-Id: I3c92a07233b2174c5731d6fa7fbb9ca3a97beb6b
Reviewed-on: https://go-review.googlesource.com/17237
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
The Scan function's interface to the split function was not sufficient
to handle an empty final token in a pure function; state was required.
This was ugly.
We introduce a special error value that a split function can return
that signals that this token is OK, but is the last one and scanning
should stop immediately _after_ this token.
The same effect could be achieved using the same trick (a special
error value) and checking for that error after Scan finishes, but it's
a little clumsy. Providing a published sentinel value in bufio is
cleaner and means everyone can use the same trick. The result
is an error-free scan.
Rewrite the test (that was only barely working) to use the value
and be more robust.
Also write a new example showing how to do it.
Fixes#11836
Change-Id: Iaae77d0f95b4a2efa0175ced94d93c66353079e8
Reviewed-on: https://go-review.googlesource.com/14924
Reviewed-by: Ian Lance Taylor <iant@golang.org>
I was being too clever, as usual. Write the obvious code to make sure
that when we grow the buffer we don't overflow.
Change-Id: I1641831177b0bb8a89ab6e9bcabccf6c2fcfe1d2
Reviewed-on: https://go-review.googlesource.com/14781
Reviewed-by: Minux Ma <minux@golang.org>
Add Scanner.Buffer, which lets the user give a buffer to
the scanner and set the maximum token size.
We call it Buffer not SetBuffer for consistency with Split, which
perhaps should have been called SetSplit; too late regardless.
Both Buffer and Split panic if they are called after Scan. The
panic in Split is new, but the comment on the method already
said it needed to be called first, so we might as well add the
verification while we're doing it for Buffer.
This method allows precise user control of storage.
Fixes#11702.
Change-Id: I80e3d0e3830562fdabd4f7b08f322e1378248c39
Reviewed-on: https://go-review.googlesource.com/14599
Reviewed-by: Andrew Gerrand <adg@golang.org>
Reviewed-by: roger peppe <rogpeppe@gmail.com>
The default value for error is nil so there is no need to assign this
value here.
Change-Id: I4714ef7607996ccbf91b704390e1d1d39ee3847b
Reviewed-on: https://go-review.googlesource.com/12355
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reader.Discard is the complement to Peek. It discards the next n bytes
of input.
We already have Reader.Buffered to see how many bytes of data are
sitting available in memory, and Reader.Peek to get that that buffer
directly. But once you're done with the Peek'd data, you can't get rid
of it, other than Reading it.
Both Read and io.CopyN(ioutil.Discard, bufReader, N) are relatively
slow. People instead resort to multiple blind ReadByte calls, just to
advance the internal b.r variable.
I've wanted this previously, several people have asked for it in the
past on golang-nuts/dev, and somebody just asked me for it again in a
private email. There are a few places in the standard library we'd use
it too.
Change-Id: I85dfad47704a58bd42f6867adbc9e4e1792bc3b0
Reviewed-on: https://go-review.googlesource.com/2260
Reviewed-by: Russ Cox <rsc@golang.org>
The new rules for split functions mean that we are exposed
to the common bug of a function that loops forever at EOF.
Pick these off by shutting down the scanner if too many
consecutive empty tokens are delivered.
Fixes#9020.
LGTM=rsc, adg
R=golang-codereviews, rsc, adg, bradfitz
CC=golang-codereviews
https://golang.org/cl/169970043
