encoding

Documentation

Overview

Package encoding defines an interface for character encodings, such as Shift JIS and Windows 1252, that can convert to and from UTF-8.

Encoding implementations are provided in other packages, such as golang.org/x/text/encoding/charmap and golang.org/x/text/encoding/japanese.

Index

• Constants
• Variables
• type Decoder
  • func (d *Decoder) Bytes(b []byte) ([]byte, error)
  • func (d *Decoder) Reader(r io.Reader) io.Reader
  • func (d *Decoder) String(s string) (string, error)
• type Encoder
  • func HTMLEscapeUnsupported(e *Encoder) *Encoder
  • func ReplaceUnsupported(e *Encoder) *Encoder
  • func (e *Encoder) Bytes(b []byte) ([]byte, error)
  • func (e *Encoder) String(s string) (string, error)
  • func (e *Encoder) Writer(w io.Writer) io.Writer
• type Encoding

Constants

const ASCIISub = '\x1a'

ASCIISub is the ASCII substitute character, as recommended by https://unicode.org/reports/tr36/#Text_Comparison

Variables

var ErrInvalidUTF8 = errors.New("encoding: invalid UTF-8")

ErrInvalidUTF8 means that a transformer encountered invalid UTF-8.

var UTF8Validator transform.Transformer = utf8Validator{}

UTF8Validator is a transformer that returns ErrInvalidUTF8 on the first input byte that is not valid UTF-8.

Types

type Decoder

type Decoder struct {
	transform.Transformer
	// contains filtered or unexported fields
}

A Decoder converts bytes to UTF-8. It implements transform.Transformer.

Transforming source bytes that are not of that encoding will not result in an error per se. Each byte that cannot be transcoded will be represented in the output by the UTF-8 encoding of '\uFFFD', the replacement rune.

func (*Decoder) Bytes

func (d *Decoder) Bytes(b []byte) ([]byte, error)

Bytes converts the given encoded bytes to UTF-8. It returns the converted bytes or nil, err if any error occurred.

func (*Decoder) Reader

func (d *Decoder) Reader(r io.Reader) io.Reader

Reader wraps another Reader to decode its bytes.

The Decoder may not be used for any other operation as long as the returned Reader is in use.

func (*Decoder) String

func (d *Decoder) String(s string) (string, error)

String converts the given encoded string to UTF-8. It returns the converted string or "", err if any error occurred.

type Encoder

type Encoder struct {
	transform.Transformer
	// contains filtered or unexported fields
}

An Encoder converts bytes from UTF-8. It implements transform.Transformer.

Each rune that cannot be transcoded will result in an error. In this case, the transform will consume all source byte up to, not including the offending rune. Transforming source bytes that are not valid UTF-8 will be replaced by `\uFFFD`. To return early with an error instead, use transform.Chain to preprocess the data with a UTF8Validator.

func HTMLEscapeUnsupported

func HTMLEscapeUnsupported(e *Encoder) *Encoder

HTMLEscapeUnsupported wraps encoders to replace source runes outside the repertoire of the destination encoding with HTML escape sequences.

This wrapper exists to comply to URL and HTML forms requiring a non-terminating legacy encoder. The produced sequences may lead to data loss as they are indistinguishable from legitimate input. To avoid this issue, use UTF-8 encodings whenever possible.

func ReplaceUnsupported

func ReplaceUnsupported(e *Encoder) *Encoder

ReplaceUnsupported wraps encoders to replace source runes outside the repertoire of the destination encoding with an encoding-specific replacement.

This wrapper is only provided for backwards compatibility and legacy handling. Its use is strongly discouraged. Use UTF-8 whenever possible.

func (*Encoder) Bytes

func (e *Encoder) Bytes(b []byte) ([]byte, error)

Bytes converts bytes from UTF-8. It returns the converted bytes or nil, err if any error occurred.

func (*Encoder) String

func (e *Encoder) String(s string) (string, error)

String converts a string from UTF-8. It returns the converted string or "", err if any error occurred.

func (*Encoder) Writer

func (e *Encoder) Writer(w io.Writer) io.Writer

Writer wraps another Writer to encode its UTF-8 output.

The Encoder may not be used for any other operation as long as the returned Writer is in use.

type Encoding

type Encoding interface {
	// NewDecoder returns a Decoder.
	NewDecoder() *Decoder

	// NewEncoder returns an Encoder.
	NewEncoder() *Encoder
}

Encoding is a character set encoding that can be transformed to and from UTF-8.

var Nop Encoding = nop{}

Nop is the nop encoding. Its transformed bytes are the same as the source bytes; it does not replace invalid UTF-8 sequences.

var Replacement Encoding = replacement{}

Replacement is the replacement encoding. Decoding from the replacement encoding yields a single '\uFFFD' replacement rune. Encoding from UTF-8 to the replacement encoding yields the same as the source bytes except that invalid UTF-8 is converted to '\uFFFD'.

It is defined at http://encoding.spec.whatwg.org/#replacement