Manual class transform

src/ol/TileCache.js

@@ -11,46 +11,48 @@ import {fromKey, getKey} from './tilecoord.js';
  * @param {number=} opt_highWaterMark High water mark.
  * @struct
  */
-const TileCache = function(opt_highWaterMark) {
+class TileCache {
+  constructor(opt_highWaterMark) {
 
-  LRUCache.call(this, opt_highWaterMark);
+    LRUCache.call(this, opt_highWaterMark);
 
-};
+  }
+
+  /**
+   * @param {!Object.<string, module:ol/TileRange>} usedTiles Used tiles.
+   */
+  expireCache(usedTiles) {
+    while (this.canExpireCache()) {
+      const tile = this.peekLast();
+      const zKey = tile.tileCoord[0].toString();
+      if (zKey in usedTiles && usedTiles[zKey].contains(tile.tileCoord)) {
+        break;
+      } else {
+        this.pop().dispose();
+      }
+    }
+  }
+
+  /**
+   * Prune all tiles from the cache that don't have the same z as the newest tile.
+   */
+  pruneExceptNewestZ() {
+    if (this.getCount() === 0) {
+      return;
+    }
+    const key = this.peekFirstKey();
+    const tileCoord = fromKey(key);
+    const z = tileCoord[0];
+    this.forEach(function(tile) {
+      if (tile.tileCoord[0] !== z) {
+        this.remove(getKey(tile.tileCoord));
+        tile.dispose();
+      }
+    }, this);
+  }
+}
 
 inherits(TileCache, LRUCache);
 
 
-/**
- * @param {!Object.<string, module:ol/TileRange>} usedTiles Used tiles.
- */
-TileCache.prototype.expireCache = function(usedTiles) {
-  while (this.canExpireCache()) {
-    const tile = this.peekLast();
-    const zKey = tile.tileCoord[0].toString();
-    if (zKey in usedTiles && usedTiles[zKey].contains(tile.tileCoord)) {
-      break;
-    } else {
-      this.pop().dispose();
-    }
-  }
-};
-
-
-/**
- * Prune all tiles from the cache that don't have the same z as the newest tile.
- */
-TileCache.prototype.pruneExceptNewestZ = function() {
-  if (this.getCount() === 0) {
-    return;
-  }
-  const key = this.peekFirstKey();
-  const tileCoord = fromKey(key);
-  const z = tileCoord[0];
-  this.forEach(function(tile) {
-    if (tile.tileCoord[0] !== z) {
-      this.remove(getKey(tile.tileCoord));
-      tile.dispose();
-    }
-  }, this);
-};
 export default TileCache;