move demo/static/src/ts/core to src/

src/registry.ts

@@ -0,0 +1,28 @@
+/**
+ * The registry is basically a simple hashmap. It is only a little safer and
+ * more structured than a simple object.
+ */
+export class Registry<T> {
+  private map: { [key: string]: T } = {};
+
+  /**
+   * Add an element to the registry.  Note that the add method returns the
+   * registry, to it can be chained.
+   */
+  add(key: string, item: T): Registry<T> {
+    if (key in this.map) {
+      throw new Error(`Key ${key} already exists!`);
+    }
+    this.map[key] = item;
+    return this;
+  }
+
+  /**
+   * Returns the element corresponding to the key
+   *
+   * Nothing is done to check that the key actually exists.
+   */
+  get(key: string): T | undefined {
+    return this.map[key];
+  }
+}