replacer.go 1.0 KB

1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556
  1. package stringx
  2. import "strings"
  3. type (
  4. // Replacer interface wraps the Replace method.
  5. Replacer interface {
  6. Replace(text string) string
  7. }
  8. replacer struct {
  9. *node
  10. mapping map[string]string
  11. }
  12. )
  13. // NewReplacer returns a Replacer.
  14. func NewReplacer(mapping map[string]string) Replacer {
  15. rep := &replacer{
  16. node: new(node),
  17. mapping: mapping,
  18. }
  19. for k := range mapping {
  20. rep.add(k)
  21. }
  22. rep.build()
  23. return rep
  24. }
  25. // Replace replaces text with given substitutes.
  26. func (r *replacer) Replace(text string) string {
  27. var buf strings.Builder
  28. target := []rune(text)
  29. cur := r.node
  30. nextStart := 0
  31. for len(target) != 0 {
  32. used, jump, matched := cur.longestMatch(target, nextStart)
  33. if matched {
  34. replaced := r.mapping[string(target[:used])]
  35. target = append([]rune(replaced), target[used:]...)
  36. cur = r.node
  37. } else {
  38. buf.WriteString(string(target[:used]))
  39. target = target[used:]
  40. if jump != nil {
  41. cur = jump
  42. nextStart = jump.depth
  43. } else {
  44. cur = r.node
  45. nextStart = 0
  46. }
  47. }
  48. }
  49. return buf.String()
  50. }