s2

Documentation

Overview

Package s2 provides a geolocation abstraction based on Google's S2 library.

See https://s2geometry.io/

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Index

• Variables
• func IsZero(lat, lng float64) bool
• func LatLng(token string) (lat, lng float64)
• func Level(km float64) (level int)
• func NormalizeToken(token string) string
• func Prefix(token string) string
• func PrefixedRange(token string, level int) (start, end string)
• func PrefixedToken(lat, lng float64) string
• func Range(token string, level int) (start, end string)
• func Token(lat, lng float64) string
• func TokenLevel(lat, lng float64, level int) string

Variables

var DefaultLevel = 21

DefaultLevel specifies the default S2 cell size.

var TokenPrefix = "s2:"

Functions

func IsZero

func IsZero(lat, lng float64) bool

IsZero returns true if the coordinates are both empty.

func LatLng

func LatLng(token string) (lat, lng float64)

LatLng returns the coordinates for a S2 cell token.

func Level

func Level(km float64) (level int)

Level returns the applicable cell level based on the search range in km, see https://s2geometry.io/resources/s2cell_statistics.html.

func NormalizeToken

func NormalizeToken(token string) string

NormalizeToken removes the prefix from a token and converts all characters to lower case.

func Prefix

func Prefix(token string) string

Prefix adds a token prefix if not exists.

func PrefixedRange

func PrefixedRange(token string, level int) (start, end string)

PrefixedRange returns a prefixed token range to find nearby cells within the specified S2 level.

func PrefixedToken

func PrefixedToken(lat, lng float64) string

PrefixedToken returns the prefixed S2 cell token for coordinates using the default level.

func Range

func Range(token string, level int) (start, end string)

Range returns a token range to find nearby cells within the specified S2 level.

func Token

func Token(lat, lng float64) string

Token returns the S2 cell token for coordinates using the default level.

func TokenLevel

func TokenLevel(lat, lng float64, level int) string

TokenLevel returns the S2 cell token for coordinates.