utf8string

Documentation

Overview

Package utf8string provides an efficient way to index strings by rune rather than by byte.

Index

• type String
  • func NewString(contents string) *String
  • func (s *String) At(i int) rune
  • func (s *String) Init(contents string) *String
  • func (s *String) IsASCII() bool
  • func (s *String) RuneCount() int
  • func (s *String) Slice(i, j int) string
  • func (s *String) String() string

Types

type String

type String struct {
	// contains filtered or unexported fields
}

String wraps a regular string with a small structure that provides more efficient indexing by code point index, as opposed to byte index. Scanning incrementally forwards or backwards is O(1) per index operation (although not as fast a range clause going forwards). Random access is O(N) in the length of the string, but the overhead is less than always scanning from the beginning. If the string is ASCII, random access is O(1). Unlike the built-in string type, String has internal mutable state and is not thread-safe.

func NewString

func NewString(contents string) *String

NewString returns a new UTF-8 string with the provided contents.

func (*String) At

func (s *String) At(i int) rune

At returns the rune with index i in the String. The sequence of runes is the same as iterating over the contents with a "for range" clause.

func (*String) Init

func (s *String) Init(contents string) *String

Init initializes an existing String to hold the provided contents. It returns a pointer to the initialized String.

func (*String) IsASCII

func (s *String) IsASCII() bool

IsASCII returns a boolean indicating whether the String contains only ASCII bytes.

func (*String) RuneCount

func (s *String) RuneCount() int

RuneCount returns the number of runes (Unicode code points) in the String.

func (*String) Slice

func (s *String) Slice(i, j int) string

Slice returns the string sliced at rune positions [i:j].

func (*String) String

func (s *String) String() string

String returns the contents of the String. This method also means the String is directly printable by fmt.Print.