FlitsGeohash

FlitsGeohash is a Swift package for working with geohashes on Apple platforms and Linux. It wraps a small C implementation with a Swift-friendly API for encoding coordinates, finding adjacent cells, collecting neighbors, and generating the geohashes that cover a region.

Features

• Encode CLLocationCoordinate2D values into geohash strings
• Get adjacent geohashes in the four cardinal directions
• Fetch all 8 neighboring geohashes
• Generate the geohashes that cover a map region
• Use strongly typed fixed-length geohashes for common lengths
• Use the same coordinate API on Linux without depending on CoreLocation

Requirements

• Swift 6.0+
• Apple platforms where CoreLocation is available
• Linux

When CoreLocation is unavailable, FlitsGeohash provides compatible CLLocationCoordinate2D, CLLocationDegrees, and CLLocationCoordinate2DIsValid definitions so the public API stays the same across platforms.

Installation

Add the package to your Package.swift:

dependencies: [
    .package(url: "https://github.com/flitsmeister/FlitsGeohash.git", from: "1.3.0")
]

Then add the product to your target:

targets: [
    .target(
        name: "YourTarget",
        dependencies: [
            .product(name: "FlitsGeohash", package: "FlitsGeohash")
        ]
    )
]

Usage

Encode a coordinate

#if canImport(CoreLocation)
import CoreLocation
#endif
import FlitsGeohash

let coordinate = CLLocationCoordinate2D(
    latitude: 57.64911063015461,
    longitude: 10.40743969380855
)

let hash = Geohash.hash(coordinate, length: 11)
// "u4pruydqqvj"

let shortHash = coordinate.geohash(length: 5)
// "u4pru"

The string-based API accepts geohash lengths from 1...22.

On Linux, the snippet above works unchanged. FlitsGeohash exposes a compatible coordinate type when CoreLocation is not available.

Adjacent cells and neighbors

let hash = "u4pruydqqvj"

let north = Geohash.adjacent(hash: hash, direction: .north)
// "u4pruydqqvm"

let neighbors = Geohash.neighbors(hash: hash)
print(neighbors.east)       // "u4pruydqqvn"
print(neighbors.southWest)  // "u4pruydqquu"
print(neighbors.allNeighbors)

Cover a region with geohashes

let hashes = Geohash.hashesForRegion(
    centerCoordinate: .init(latitude: 57.64911063015461, longitude: 10.40743969380855),
    latitudeDelta: 2,
    longitudeDelta: 2,
    length: 3
)

print(hashes.sorted())
// ["u4n", "u4p", "u4q", "u4r", "u60", "u62"]

Use fixed-length geohash types

For stricter code, the package also exposes typed geohashes for lengths 1...11:

let geohash = Geohash11(coordinate)
print(geohash.string) // "u4pruydqqvj"

let neighbors = geohash.neighbors()
print(neighbors.north.string) // "u4pruydqqvm"

let lowerPrecision: Geohash5? = geohash.toLowerLength()
print(lowerPrecision?.string as Any) // Optional("u4pru")

Typed region coverage is also available:

let regionHashes = Geohash3.hashesForRegion(
    centerCoordinate: .init(latitude: 57.64911063015461, longitude: 10.40743969380855),
    latitudeDelta: 2,
    longitudeDelta: 2
)

Running Tests

swift test

The test suite includes correctness checks and performance-oriented coverage for encoding, adjacency, neighbors, and region generation, and CI runs on both macOS and Ubuntu.

Contributing

See CONTRIBUTING.md.