mirror of https://github.com/tidwall/tile38.git
76 lines
1.3 KiB
Go
76 lines
1.3 KiB
Go
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package stringprep
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import (
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"golang.org/x/text/unicode/norm"
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)
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// Profile represents a stringprep profile.
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type Profile struct {
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Mappings []Mapping
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Normalize bool
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Prohibits []Set
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CheckBiDi bool
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}
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var errProhibited = "prohibited character"
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// Prepare transforms an input string to an output string following
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// the rules defined in the profile as defined by RFC-3454.
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func (p Profile) Prepare(s string) (string, error) {
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// Optimistically, assume output will be same length as input
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temp := make([]rune, 0, len(s))
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// Apply maps
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for _, r := range s {
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rs, ok := p.applyMaps(r)
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if ok {
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temp = append(temp, rs...)
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} else {
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temp = append(temp, r)
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}
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}
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// Normalize
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var out string
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if p.Normalize {
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out = norm.NFKC.String(string(temp))
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} else {
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out = string(temp)
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}
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// Check prohibited
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for _, r := range out {
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if p.runeIsProhibited(r) {
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return "", Error{Msg: errProhibited, Rune: r}
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}
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}
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// Check BiDi allowed
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if p.CheckBiDi {
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if err := passesBiDiRules(out); err != nil {
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return "", err
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}
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}
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return out, nil
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}
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func (p Profile) applyMaps(r rune) ([]rune, bool) {
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for _, m := range p.Mappings {
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rs, ok := m.Map(r)
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if ok {
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return rs, true
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}
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}
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return nil, false
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}
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func (p Profile) runeIsProhibited(r rune) bool {
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for _, s := range p.Prohibits {
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if s.Contains(r) {
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return true
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}
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}
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return false
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}
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