ianlewis / runeio

Package runeio provides a buffered RuneReader/RuneScanner implementation for Go.

runeio

runeio is a Go package that provides basic interfaces to I/O primitives for runes. Its primary job is to wrap and supplement existing implementations of such primitives, such as those in package io.

Because these interfaces and primitives wrap lower-level operations with various implementations, unless otherwise informed clients should not assume they are safe for parallel execution.

The package provides a buffered RuneReader that implements the io.RuneScanner interface. Its primary purpose is to buffer the reading of runes and allow users to Peek ahead by a number of runes rather than a number of bytes as with the bufio.Reader.

Examples

A single rune can be read with ReadRune.

r := runeio.NewReader(strings.NewReader("Hello World!"))

var runes []rune
for {
  rn, _, err := r.ReadRune()
  if err != nil {
    break
  }
  runes = append(runes, rn)
}

fmt.Print(string(runes))

// Output: Hello World!

Read can be used to read runes into a buffer.

r := runeio.NewReader(strings.NewReader("Hello World!"))

buf := make([]rune, 5)
_, _ = r.Read(buf)

fmt.Print(string(buf))

// Output: Hello

Peek can be used to look ahead into the stream without consuming the runes.

r := runeio.NewReader(strings.NewReader("Hello World!"))

buf := make([]rune, 6)
_, _ = r.Read(buf)
peeked, _ := r.Peek(6)

fmt.Print(string(peeked))

// Output: World!

Related Projects

• pelletier/go-buffruneio: Another buffering implementation of io.RuneScanner.
  • Uses a custom badRune value for encoding errors instead of unicode.ReplacementChar
  • Uses a custom EOF rune value instead of just returning io.EOF.
  • The undo buffer grows unbounded until Forget is called.
  • NewReader also takes a io.Reader which is wrapped in a bufio.Reader when it could just take an io.RuneReader since it the implementation only requiresReadRune from the underlying reader.
• SteelSeries/bufrr: Another buffering implementation of io.RuneScanner.
  • Implements only a static single rune buffer. This means that only one rune could be peeked at.

Contributing

See CONTRIBUTING.md