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go-zero/core/stringx/replacer.go

85 lines
1.5 KiB
Go

package stringx
import (
"sort"
"strings"
)
// replace more than once to avoid overlapped keywords after replace.
// only try 2 times to avoid too many or infinite loops.
const replaceTimes = 2
type (
// Replacer interface wraps the Replace method.
Replacer interface {
Replace(text string) string
}
replacer struct {
*node
mapping map[string]string
}
)
// NewReplacer returns a Replacer.
func NewReplacer(mapping map[string]string) Replacer {
rep := &replacer{
node: new(node),
mapping: mapping,
}
for k := range mapping {
rep.add(k)
}
rep.build()
return rep
}
// Replace replaces text with given substitutes.
func (r *replacer) Replace(text string) string {
for i := 0; i < replaceTimes; i++ {
var replaced bool
if text, replaced = r.doReplace(text); !replaced {
return text
}
}
return text
}
func (r *replacer) doReplace(text string) (string, bool) {
chars := []rune(text)
scopes := r.find(chars)
if len(scopes) == 0 {
return text, false
}
sort.Slice(scopes, func(i, j int) bool {
if scopes[i].start < scopes[j].start {
return true
}
if scopes[i].start == scopes[j].start {
return scopes[i].stop > scopes[j].stop
}
return false
})
var buf strings.Builder
var index int
for i := 0; i < len(scopes); i++ {
scp := &scopes[i]
if scp.start < index {
continue
}
buf.WriteString(string(chars[index:scp.start]))
buf.WriteString(r.mapping[string(chars[scp.start:scp.stop])])
index = scp.stop
}
if index < len(chars) {
buf.WriteString(string(chars[index:]))
}
return buf.String(), true
}