code review 5654048: unicode/utf8: document return value for decode errors

unicode/utf8: document return value for decode errors
Also replace archaic definition of rune.

[r, 2012-02-10 03:06:05]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://go.googlecode.com/hg/

[bradfitz, 2012-02-10 03:07:24]

LGTM

On Fri, Feb 10, 2012 at 2:06 PM, <r@golang.org> wrote:

> Reviewers: golang-dev_googlegroups.com,
>
> Message:
> Hello golang-dev@googlegroups.com,
>
> I'd like you to review this change to
> https://go.googlecode.com/hg/
>
>
> Description:
> unicode/utf8: document return value for decode errors
> Also replace archaic definition of rune.
>
> Please review this at
http://codereview.appspot.com/**5654048/<http://codereview.appspot.com/5654048/>
>
> Affected files:
>  M src/pkg/unicode/utf8/utf8.go
>
>
> Index: src/pkg/unicode/utf8/utf8.go
> ==============================**==============================**=======
> --- a/src/pkg/unicode/utf8/utf8.go
> +++ b/src/pkg/unicode/utf8/utf8.go
> @@ -3,7 +3,7 @@
>  // license that can be found in the LICENSE file.
>
>  // Package utf8 implements functions and constants to support text
> encoded in
> -// UTF-8. This package calls a Unicode character a rune for brevity.
> +// UTF-8. It includes functions to translate between runes and UTF-8 byte
> sequences.
>  package utf8
>
>  import "unicode" // only needed for a couple of constants
> @@ -198,19 +198,21 @@
>  }
>
>  // DecodeRune unpacks the first UTF-8 encoding in p and returns the rune
> and its width in bytes.
> +// If the encoding is invalid, it returns (RuneError, 1), an impossible
> result for correct UTF-8.
>  func DecodeRune(p []byte) (r rune, size int) {
>        r, size, _ = decodeRuneInternal(p)
>        return
>  }
>
>  // DecodeRuneInString is like DecodeRune but its input is a string.
> +// If the encoding is invalid, it returns (RuneError, 1), an impossible
> result for correct UTF-8.
>  func DecodeRuneInString(s string) (r rune, size int) {
>        r, size, _ = decodeRuneInStringInternal(s)
>        return
>  }
>
> -// DecodeLastRune unpacks the last UTF-8 encoding in p
> -// and returns the rune and its width in bytes.
> +// DecodeLastRune unpacks the last UTF-8 encoding in p and returns the
> rune and its width in bytes.
> +// If the encoding is invalid, it returns (RuneError, 1), an impossible
> result for correct UTF-8.
>  func DecodeLastRune(p []byte) (r rune, size int) {
>        end := len(p)
>        if end == 0 {
> @@ -244,6 +246,7 @@
>  }
>
>  // DecodeLastRuneInString is like DecodeLastRune but its input is a
> string.
> +// If the encoding is invalid, it returns (RuneError, 1), an impossible
> result for correct UTF-8.
>  func DecodeLastRuneInString(s string) (r rune, size int) {
>        end := len(s)
>        if end == 0 {
>
>
>

[r, 2012-02-10 03:12:23]

*** Submitted as http://code.google.com/p/go/source/detail?r=58e600a849f2 ***

unicode/utf8: document return value for decode errors
Also replace archaic definition of rune.

R=golang-dev, bradfitz
CC=golang-dev
http://codereview.appspot.com/5654048