Allow an array to be used for aStar functions

a-star.ts

@@ -37,7 +37,7 @@ namespace scene {
     //% onTilesOf.decompileIndirectFixedInstances=true
     //% help=github:arcade-tilemap-a-star/docs/a-star
     //% group="Path Following" weight=10
-    export function aStar(start: tiles.Location, end: tiles.Location, onTilesOf: Image = null) {
+    export function aStar(start: tiles.Location, end: tiles.Location, onTilesOf: Image | Image[] = null) {
         const tm = game.currentScene().tileMap;
         if (!tm || !start || !end)
             return undefined;
@@ -52,7 +52,7 @@ namespace scene {
             l => l.col == end1.col && l.row == end1.row);
     }
 
-    export function aStarToAnyOfType(start: tiles.Location, tile: Image, onTilesOf: Image) {
+    export function aStarToAnyOfType(start: tiles.Location, tile: Image, onTilesOf: Image | Image[]) {
         const tm = game.currentScene().tileMap;
         if (!tm || !start)
             return undefined;
@@ -70,7 +70,7 @@ namespace scene {
             });
     }
 
-    export function generalAStar(tm: tiles.TileMap, start: SimpleLocation, onTilesOf: Image,
+    export function generalAStar(tm: tiles.TileMap, start: SimpleLocation, onTilesOf: Image | Image[],
         heuristic: (tile: SimpleLocation) => number,
         isEnd: (tile: SimpleLocation) => boolean): tiles.Location[] {
 
@@ -228,10 +228,22 @@ namespace scene {
             (DIAGONAL_COST - NEIGHBOR_COST)
     }
 
-    function isWalkable(loc: SimpleLocation, onTilesOf: Image, tm: tiles.TileMap): boolean {
+    function isWalkable(loc: SimpleLocation, onTilesOf: Image | Image[], tm: tiles.TileMap): boolean {
         if (tm.isObstacle(loc.col, loc.row)) return false;
         if (!onTilesOf) return true;
         const img = tm.getTileImage(tm.getTileIndex(loc.col, loc.row))
-        return img.equals(onTilesOf);
+        if (isImageLike(onTilesOf)) return img.equals(onTilesOf)
+        if (isArrayLike<Image>(onTilesOf)) return onTilesOf.some((item: Image) => img.equals(item));
+        return true
+    }
+
+    function isArrayLike<T>(val: T | T[]): val is Array<T> {
+        return val && typeof(val) === "object" &&
+            Object.keys(val).some(k => k == "length");
+    }
+    function isImageLike(val: any): val is Image {
+        return val && typeof (val) === "object" &&
+            Object.keys(val).some(k => k == "width") &&
+            Object.keys(val).some(k => k == "height");
     }
 }

pxt.json

@@ -1,6 +1,6 @@
 {
     "name": "arcade-tilemap-a-star",
-    "version": "0.4.0",
+    "version": "0.4.1",
     "description": "",
     "dependencies": {
         "device": "*"