code review 5754046: unicode/utf8: remove dependence on unicode.

unicode/utf8: remove dependence on unicode.
The dependency was there only to pull in two constants.
Now we define them locally and verify equality in the test.

[r, 2012-03-06 00:00:25]

Hello golang-dev@googlegroups.com,

I'd like you to review this change to
https://code.google.com/p/go/

[bradfitz, 2012-03-06 00:03:47]

LGTM but validate the ______ ?

On Mon, Mar 5, 2012 at 4:00 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://code.google.com/p/go/
>
>
> Description:
> unicode/utf8: remove dependence on unicode.
> The dependency was there only to pull in two constants.
> Now we define them locally and verify equality in the test.
>
> Please review this at
http://codereview.appspot.com/**5754046/<http://codereview.appspot.com/5754046/>
>
> Affected files:
>  M src/pkg/unicode/utf8/utf8.go
>  M src/pkg/unicode/utf8/utf8_**test.go
>
>
> Index: src/pkg/unicode/utf8/utf8.go
> ==============================**==============================**=======
> --- a/src/pkg/unicode/utf8/utf8.go
> +++ b/src/pkg/unicode/utf8/utf8.go
> @@ -6,13 +6,17 @@
>  // 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
> +// The conditions RuneError==unicode.**ReplacementChar and
> +// MaxRune==unicode.MaxRune are verified in the tests.
> +// Defining them locally avoids this package depending on package
> +// unicode.
>
>  // Numbers fundamental to the encoding.
>  const (
> -       RuneError = unicode.ReplacementChar // the "error" Rune or
> "replacement character".
> -       RuneSelf  = 0x80                    // characters below Runeself
> are represented as themselves in a single byte.
> -       UTFMax    = 4                       // maximum number of bytes of
> a UTF-8 encoded Unicode character.
> +       RuneError = '\uFFFD'     // the "error" Rune or "Unicode
> replacement character"
> +       RuneSelf  = 0x80         // characters below Runeself are
> represented as themselves in a single byte.
> +       MaxRune   = '\U0010FFFF' // Maximum valid Unicode code point.
> +       UTFMax    = 4            // maximum number of bytes of a UTF-8
> encoded Unicode character.
>  )
>
>  const (
> @@ -309,7 +313,7 @@
>                return 2
>        }
>
> -       if uint32(r) > unicode.MaxRune {
> +       if uint32(r) > MaxRune {
>                r = RuneError
>        }
>
> Index: src/pkg/unicode/utf8/utf8_**test.go
> ==============================**==============================**=======
> --- a/src/pkg/unicode/utf8/utf8_**test.go
> +++ b/src/pkg/unicode/utf8/utf8_**test.go
> @@ -7,9 +7,20 @@
>  import (
>        "bytes"
>        "testing"
> +       "unicode"
>        . "unicode/utf8"
>  )
>
> +// Validate the
> +func init() {
> +       if MaxRune != unicode.MaxRune {
> +               panic("utf8.MaxRune is wrong")
> +       }
> +       if RuneError != unicode.ReplacementChar {
> +               panic("utf8.RuneError is wrong")
> +       }
> +}
> +
>  type Utf8Map struct {
>        r   rune
>        str string
>
>
>

[r, 2012-03-06 00:14:50]

*** Submitted as http://code.google.com/p/go/source/detail?r=0916d0c46bb7 ***

unicode/utf8: remove dependence on unicode.
The dependency was there only to pull in two constants.
Now we define them locally and verify equality in the test.

R=golang-dev, bradfitz
CC=golang-dev
http://codereview.appspot.com/5754046