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package stringprep
import (
"golang.org/x/text/unicode/norm"
)
// Profile represents a stringprep profile.
type Profile struct {
Mappings []Mapping
Normalize bool
Prohibits []Set
CheckBiDi bool
}
var errProhibited = "prohibited character"
// Prepare transforms an input string to an output string following
// the rules defined in the profile as defined by RFC-3454.
func (p Profile) Prepare(s string) (string, error) {
// Optimistically, assume output will be same length as input
temp := make([]rune, 0, len(s))
// Apply maps
for _, r := range s {
rs, ok := p.applyMaps(r)
if ok {
temp = append(temp, rs...)
} else {
temp = append(temp, r)
}
}
// Normalize
var out string
if p.Normalize {
out = norm.NFKC.String(string(temp))
} else {
out = string(temp)
}
// Check prohibited
for _, r := range out {
if p.runeIsProhibited(r) {
return "", Error{Msg: errProhibited, Rune: r}
}
}
// Check BiDi allowed
if p.CheckBiDi {
if err := passesBiDiRules(out); err != nil {
return "", err
}
}
return out, nil
}
func (p Profile) applyMaps(r rune) ([]rune, bool) {
for _, m := range p.Mappings {
rs, ok := m.Map(r)
if ok {
return rs, true
}
}
return nil, false
}
func (p Profile) runeIsProhibited(r rune) bool {
for _, s := range p.Prohibits {
if s.Contains(r) {
return true
}
}
return false
}
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