Namespace: go.std.unicode.utf8

v1.0

Contents

• Summary
• Index
• Constants
• Variables
• Functions, Macros, and Special Forms
• Types

Summary

Provides a low-level interface to the unicode/utf8 package.

Package utf8 implements functions and constants to support text encoded in
UTF-8. It includes functions to translate between runes and UTF-8 byte sequences.
See https://en.wikipedia.org/wiki/UTF-8

Index

• AppendRune
• DecodeLastRune
• DecodeLastRuneInString
• DecodeRune
• DecodeRuneInString
• EncodeRune
• FullRune
• FullRuneInString
• MaxRune
• RuneCount
• RuneCountInString
• RuneError
• RuneLen
• RuneSelf
• RuneStart
• UTFMax
• Valid
• ValidRune
• ValidString

Legend

Constant Variable Function Macro Special form Type GoVar Receiver/Method

Constants

Constants are variables with :const true in their metadata. Joker currently does not recognize them as special; as such, it allows redefining them or their values.

• MaxRune

  Char v1.0

  Maximum valid Unicode code point.
  

• RuneError

  Char v1.0

  the "error" Rune or "Unicode replacement character"
  

• RuneSelf

  Int v1.0

  characters below RuneSelf are represented as themselves in a single byte.
  

• UTFMax

  Int v1.0

  maximum number of bytes of a UTF-8 encoded Unicode character.
  

Variables

(None.)

Functions, Macros, and Special Forms

• AppendRune

  Function v1.0

  (AppendRune p r)
  

  AppendRune appends the UTF-8 encoding of r to the end of p and
  returns the extended buffer. If the rune is out of range,
  it appends the encoding of RuneError.
  
  Go input arguments: (p []byte, r rune)
  
  Go returns: []byte
  
  Joker input arguments: [^arrayOfByte p, ^Char r]
  
  Joker returns: ^arrayOfByte

• DecodeLastRune

  Function v1.0

  (DecodeLastRune p)
  

  DecodeLastRune unpacks the last UTF-8 encoding in p and returns the rune and
  its width in bytes. If p is empty it returns (RuneError, 0). Otherwise, if
  the encoding is invalid, it returns (RuneError, 1). Both are impossible
  results for correct, non-empty UTF-8.
  
  An encoding is invalid if it is incorrect UTF-8, encodes a rune that is
  out of range, or is not the shortest possible UTF-8 encoding for the
  value. No other validation is performed.
  
  Go input arguments: (p []byte)
  
  Go returns: (r rune, size int)
  
  Joker input arguments: [^arrayOfByte p]
  
  Joker returns: [^Char r, ^Int size]

• DecodeLastRuneInString

  Function v1.0

  (DecodeLastRuneInString s)
  

  DecodeLastRuneInString is like DecodeLastRune but its input is a string. If
  s is empty it returns (RuneError, 0). Otherwise, if the encoding is invalid,
  it returns (RuneError, 1). Both are impossible results for correct,
  non-empty UTF-8.
  
  An encoding is invalid if it is incorrect UTF-8, encodes a rune that is
  out of range, or is not the shortest possible UTF-8 encoding for the
  value. No other validation is performed.
  
  Go input arguments: (s string)
  
  Go returns: (r rune, size int)
  
  Joker input arguments: [^String s]
  
  Joker returns: [^Char r, ^Int size]

• DecodeRune

  Function v1.0

  (DecodeRune p)
  

  DecodeRune unpacks the first UTF-8 encoding in p and returns the rune and
  its width in bytes. If p is empty it returns (RuneError, 0). Otherwise, if
  the encoding is invalid, it returns (RuneError, 1). Both are impossible
  results for correct, non-empty UTF-8.
  
  An encoding is invalid if it is incorrect UTF-8, encodes a rune that is
  out of range, or is not the shortest possible UTF-8 encoding for the
  value. No other validation is performed.
  
  Go input arguments: (p []byte)
  
  Go returns: (r rune, size int)
  
  Joker input arguments: [^arrayOfByte p]
  
  Joker returns: [^Char r, ^Int size]

• DecodeRuneInString

  Function v1.0

  (DecodeRuneInString s)
  

  DecodeRuneInString is like DecodeRune but its input is a string. If s is
  empty it returns (RuneError, 0). Otherwise, if the encoding is invalid, it
  returns (RuneError, 1). Both are impossible results for correct, non-empty
  UTF-8.
  
  An encoding is invalid if it is incorrect UTF-8, encodes a rune that is
  out of range, or is not the shortest possible UTF-8 encoding for the
  value. No other validation is performed.
  
  Go input arguments: (s string)
  
  Go returns: (r rune, size int)
  
  Joker input arguments: [^String s]
  
  Joker returns: [^Char r, ^Int size]

• EncodeRune

  Function v1.0

  (EncodeRune p r)
  

  EncodeRune writes into p (which must be large enough) the UTF-8 encoding of the rune.
  If the rune is out of range, it writes the encoding of RuneError.
  It returns the number of bytes written.
  
  Go input arguments: (p []byte, r rune)
  
  Go returns: int
  
  Joker input arguments: [^arrayOfByte p, ^Char r]
  
  Joker returns: ^Int

• FullRune

  Function v1.0

  (FullRune p)
  

  FullRune reports whether the bytes in p begin with a full UTF-8 encoding of a rune.
  An invalid encoding is considered a full Rune since it will convert as a width-1 error rune.
  
  Go input arguments: (p []byte)
  
  Go returns: bool
  
  Joker input arguments: [^arrayOfByte p]
  
  Joker returns: ^Boolean

• FullRuneInString

  Function v1.0

  (FullRuneInString s)
  

  FullRuneInString is like FullRune but its input is a string.
  
  Go input arguments: (s string)
  
  Go returns: bool
  
  Joker input arguments: [^String s]
  
  Joker returns: ^Boolean

• RuneCount

  Function v1.0

  (RuneCount p)
  

  RuneCount returns the number of runes in p. Erroneous and short
  encodings are treated as single runes of width 1 byte.
  
  Go input arguments: (p []byte)
  
  Go returns: int
  
  Joker input arguments: [^arrayOfByte p]
  
  Joker returns: ^Int

• RuneCountInString

  Function v1.0

  (RuneCountInString s)
  

  RuneCountInString is like RuneCount but its input is a string.
  
  Go input arguments: (s string)
  
  Go returns: int
  
  Joker input arguments: [^String s]
  
  Joker returns: ^Int n

• RuneLen

  Function v1.0

  (RuneLen r)
  

  RuneLen returns the number of bytes required to encode the rune.
  It returns -1 if the rune is not a valid value to encode in UTF-8.
  
  Go input arguments: (r rune)
  
  Go returns: int
  
  Joker input arguments: [^Char r]
  
  Joker returns: ^Int

• RuneStart

  Function v1.0

  (RuneStart b)
  

  RuneStart reports whether the byte could be the first byte of an encoded,
  possibly invalid rune. Second and subsequent bytes always have the top two
  bits set to 10.
  
  Go input arguments: (b byte)
  
  Go returns: bool
  
  Joker input arguments: [^Byte b]
  
  Joker returns: ^Boolean

• Valid

  Function v1.0

  (Valid p)
  

  Valid reports whether p consists entirely of valid UTF-8-encoded runes.
  
  Go input arguments: (p []byte)
  
  Go returns: bool
  
  Joker input arguments: [^arrayOfByte p]
  
  Joker returns: ^Boolean

• ValidRune

  Function v1.0

  (ValidRune r)
  

  ValidRune reports whether r can be legally encoded as UTF-8.
  Code points that are out of range or a surrogate half are illegal.
  
  Go input arguments: (r rune)
  
  Go returns: bool
  
  Joker input arguments: [^Char r]
  
  Joker returns: ^Boolean

• ValidString

  Function v1.0

  (ValidString s)
  

  ValidString reports whether s consists entirely of valid UTF-8-encoded runes.
  
  Go input arguments: (s string)
  
  Go returns: bool
  
  Joker input arguments: [^String s]
  
  Joker returns: ^Boolean

Types

(None.)