Mapbox iOS GeoJSON with clustering example (swift)

MapViewController.swift

//
//  MapViewController.swift
//  Mapbox Clustering Test
//
//  Created by Ester Sanchez on 18/01/17.
//  Copyright © 2017 misato.es. All rights reserved.
//

import UIKit
import Mapbox

class MapViewController: UIViewController, MGLMapViewDelegate {
    @IBOutlet weak var mapView: MGLMapView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        mapView.delegate = self
    }
  
    // Based on this example: https://gist.github.com/boundsj/1a239f5f3e4d27eb7a4fba54db328152
    // Updated for Swift 3 and Mapbox iOS SDK 3.4.0.beta 7 (January 2017)
    private func loadGeoJSON() {
        
        let url = URL(string: "https://www.mapbox.com/mapbox-gl-js/assets/earthquakes.geojson")!
        let geoJSONSource = MGLShapeSource(identifier: "earthquakes", url: url, options: [.clustered: true, .clusterRadius: 20, .maximumZoomLevelForClustering: 15])
        mapView.style?.addSource(geoJSONSource)
        
        let unclusteredLayer = MGLCircleStyleLayer(identifier: "unclustered", source: geoJSONSource)

        unclusteredLayer.circleColor = MGLStyleValue(rawValue: UIColor(colorLiteralRed: 229/255.0, green: 94/255.0, blue: 94/255.0, alpha: 1))
        unclusteredLayer.circleRadius = MGLStyleValue(rawValue: 20)
        unclusteredLayer.circleBlur = MGLStyleValue(rawValue: 15)
        unclusteredLayer.predicate = NSPredicate(format: "%K != YES", argumentArray: ["cluster"])
        
        mapView.style?.addLayer(unclusteredLayer)

        let layers = [
            (150, UIColor(colorLiteralRed: 229/255.0, green: 94/255.0, blue: 94/255.0, alpha: 1)),
            (20, UIColor(colorLiteralRed: 249/255.0, green: 136/255.0, blue: 108/255.0, alpha: 1)),
            (0, UIColor(colorLiteralRed: 251/255.0, green: 176/255.0, blue: 59/255.0, alpha: 1))
        ]
        for index in 0..<layers.count {
            let circles = MGLCircleStyleLayer(identifier: "cluster-\(index)", source: geoJSONSource)
            circles.circleColor = MGLStyleValue(rawValue: layers[index].1)
            circles.circleRadius = MGLStyleValue(rawValue: 70)
            circles.circleBlur = MGLStyleValue(rawValue: 1)
            
            let gtePredicate = NSPredicate(format: "%K >= %@", argumentArray: ["point_count", layers[index].0])
            let allPredicate = index == 0 ?
                gtePredicate :
                NSCompoundPredicate(andPredicateWithSubpredicates: [gtePredicate, NSPredicate(format: "%K < %@", argumentArray: ["point_count", layers[index - 1].0])])               

            circles.predicate = allPredicate
            
            mapView.style?.addLayer(circles)
            
        }
    }
 
    
    //MARK: - MGLMapViewDelegate
    
    func mapViewDidFinishLoadingMap(_ mapView: MGLMapView) {
        loadGeoJSON()
    }  

}

Hey, could you update it for Swift 4 and iOS 11 ? This would be extremely useful. 🥇