common/escape.go

   1 package common
   2
   3 import "bytes"
   4
   5 // Markdown escape map (ASCII)
   6 // Inspired by https://github.com/golang-commonmark/markdown/blob/master/escape.go
   7 type EscapeMap [2]uint64
   8
   9 func (e *EscapeMap) Get(index uint) bool {
  10         if index >= 128 { return false }
  11         high, low := index / 64, index % 64
  12         return e[high] & (1 << low) != 0
  13 }
  14
  15 func (e *EscapeMap) Set(index uint, x bool) {
  16         if index >= 128 { return }
  17         high, low := index / 64, index % 64
  18         if x {
  19                 e[high] = e[high] | 1 << low
  20         } else {
  21                 e[high] = e[high] &^ 1 << low
  22         }
  23 }
  24
  25 func (e EscapeMap) ToBuffer(src string, dest *bytes.Buffer) (err error) {
  26         for _, char := range src {
  27                 if char < 0x80 && e.Get(uint(char)) {
  28                         // Write backslash + char
  29                         _, err = dest.Write([]byte{0x5c, byte(char)})
  30                 } else {
  31                         _, err = dest.WriteRune(char)
  32                 }
  33         }
  34         return
  35 }
  36
  37 func (e EscapeMap) ToString(src string) (string, error) {
  38         var buffer bytes.Buffer
  39         err := e.ToBuffer(src, &buffer)
  40         if err != nil {
  41                 return "", err
  42         } else {
  43                 return buffer.String(), nil
  44         }
  45 }