44 lines
955 B
Go
44 lines
955 B
Go
package s2
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import (
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"strings"
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)
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var TokenPrefix = "s2:"
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// NormalizeToken removes the prefix from a token and converts all characters to lower case.
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func NormalizeToken(token string) string {
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token = strings.ToLower(token)
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token = strings.TrimSpace(token)
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if strings.HasPrefix(token, TokenPrefix) {
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return token[len(TokenPrefix):]
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}
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return token
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}
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// Prefix adds a token prefix if not exists.
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func Prefix(token string) string {
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if len(token) < 3 {
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return token
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}
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if strings.HasPrefix(token, TokenPrefix) {
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return token
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}
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return TokenPrefix + token
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}
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// PrefixedToken returns the prefixed S2 cell token for coordinates using the default level.
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func PrefixedToken(lat, lng float64) string {
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return Prefix(Token(lat, lng))
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}
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// PrefixedRange returns a token range for finding nearby locations.
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func PrefixedRange(token string, levelUp int) (min, max string) {
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min, max = Range(token, levelUp)
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return Prefix(min), Prefix(max)
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}
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