code review 5643045: encoding/hex: canonicalize error type names

encoding/hex: canonicalize error type names
Also simplify the tests.

Fixes issue 2849.

[r, 2012-02-07 03:48:00]

Hello golang-dev@googlegroups.com,

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

[bradfitz, 2012-02-07 04:05:52]

ErrLength shouldn't be a type.
 On Feb 6, 2012 7:48 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:
> encoding/hex: canonicalize error type names
>
> Fixes issue 2849.
>
> Please review this at
http://codereview.appspot.com/**5643045/<http://codereview.appspot.com/5643045/>
>
> Affected files:
>  M src/pkg/encoding/hex/hex.go
>
>
> Index: src/pkg/encoding/hex/hex.go
> ==============================**==============================**=======
> --- a/src/pkg/encoding/hex/hex.go
> +++ b/src/pkg/encoding/hex/hex.go
> @@ -29,15 +29,15 @@
>        return len(src) * 2
>  }
>
> -// OddLengthInputError results from decoding an odd length slice.
> -type OddLengthInputError struct{}
> +// ErrLength results from decoding an odd length slice.
> +type ErrLength struct{}
>
> -func (OddLengthInputError) Error() string { return "odd length hex
> string" }
> +func (ErrLength) Error() string { return "odd length hex string" }
>
> -// InvalidHexCharError results from finding an invalid character in a hex
> string.
> -type InvalidHexCharError byte
> +// ErrInvalid results from finding an invalid character in a hex string.
> +type ErrInvalid byte
>
> -func (e InvalidHexCharError) Error() string {
> +func (e ErrInvalid) Error() string {
>        return "invalid hex char: " + strconv.Itoa(int(e))
>  }
>
> @@ -46,21 +46,21 @@
>  // Decode decodes src into DecodedLen(len(src)) bytes, returning the
> actual
>  // number of bytes written to dst.
>  //
> -// If Decode encounters invalid input, it returns an OddLengthInputError
> or an
> -// InvalidHexCharError.
> +// If Decode encounters invalid input, it returns an ErrLength or an
> +// ErrInvalid.
>  func Decode(dst, src []byte) (int, error) {
>        if len(src)%2 == 1 {
> -               return 0, OddLengthInputError{}
> +               return 0, ErrLength{}
>        }
>
>        for i := 0; i < len(src)/2; i++ {
>                a, ok := fromHexChar(src[i*2])
>                if !ok {
> -                       return 0, InvalidHexCharError(src[i*2])
> +                       return 0, ErrInvalid(src[i*2])
>                }
>                b, ok := fromHexChar(src[i*2+1])
>                if !ok {
> -                       return 0, InvalidHexCharError(src[i*2+1]**)
> +                       return 0, ErrInvalid(src[i*2+1])
>                }
>                dst[i] = (a << 4) | b
>        }
>
>
>

[r, 2012-02-07 05:19:08]

Hello golang-dev@googlegroups.com, bradfitz@golang.org (cc:
golang-dev@googlegroups.com),

Please take another look.

[bradfitz, 2012-02-07 05:33:30]

http://codereview.appspot.com/5643045/diff/1002/src/pkg/encoding/hex/hex.go
File src/pkg/encoding/hex/hex.go (right):

http://codereview.appspot.com/5643045/diff/1002/src/pkg/encoding/hex/hex.go#n...
src/pkg/encoding/hex/hex.go:37: type ErrInvalid byte
Everywhere(?) else in the standard library, ErrFoo is a variable and FooError is
a type.

You're changing it away from the normal convention here.  Is that intentional?

[r, 2012-02-07 05:53:04]

Hello golang-dev@googlegroups.com, bradfitz@golang.org (cc:
golang-dev@googlegroups.com),

Please take another look.

[r2, 2012-02-07 05:53:13]

i need coffee.

-rob

[r2, 2012-02-07 05:55:02]

hold on.

this error thing is bogus. (not my fault!) let me fix and test

-rob

[bradfitz, 2012-02-07 05:57:29]

InvalidByteError with /or$/

Holding, per your last email.

But wheels up shortly here.
 On Feb 6, 2012 9:53 PM, <r@golang.org> wrote:

> Hello golang-dev@googlegroups.com, bradfitz@golang.org (cc:
> golang-dev@googlegroups.com),
>
> Please take another look.
>
>
>
http://codereview.appspot.com/**5643045/<http://codereview.appspot.com/5643045/>
>

[r, 2012-02-07 06:23:14]

Hello golang-dev@googlegroups.com, bradfitz@golang.org, r@google.com (cc:
golang-dev@googlegroups.com),

Please take another look.

[bradfitz, 2012-02-08 00:07:47]

http://codereview.appspot.com/5643045/diff/1006/src/pkg/encoding/hex/hex.go
File src/pkg/encoding/hex/hex.go (right):

http://codereview.appspot.com/5643045/diff/1006/src/pkg/encoding/hex/hex.go#n...
src/pkg/encoding/hex/hex.go:48: // If Decode encounters invalid input, it
returns an ErrLength or an
s/an //

http://codereview.appspot.com/5643045/diff/1006/src/pkg/encoding/hex/hex.go#n...
src/pkg/encoding/hex/hex.go:49: // ErrInvalid.
s/ErrInvalid/error of type InvalidByteError/

[r, 2012-02-08 00:14:43]

Hello golang-dev@googlegroups.com, bradfitz@golang.org, r@google.com (cc:
golang-dev@googlegroups.com),

Please take another look.

[bradfitz, 2012-02-08 00:50:34]

LGTM

On Tue, Feb 7, 2012 at 4:14 PM, <r@golang.org> wrote:

> Hello golang-dev@googlegroups.com, bradfitz@golang.org, r@google.com
> (cc: golang-dev@googlegroups.com),
>
> Please take another look.
>
>
>
http://codereview.appspot.com/**5643045/<http://codereview.appspot.com/5643045/>
>

[r, 2012-02-08 00:53:39]

*** Submitted as http://code.google.com/p/go/source/detail?r=320932bfe991 ***

encoding/hex: canonicalize error type names
Also simplify the tests.

Fixes issue 2849.

R=golang-dev, bradfitz, r
CC=golang-dev
http://codereview.appspot.com/5643045