1 files changed, 39 insertions, 0 deletions
diff --git a/llparse-builder/src/node/invoke.ts b/llparse-builder/src/node/invoke.ts
new file mode 100644
index 0000000..d6791a7
--- /dev/null
+++ b/llparse-builder/src/node/invoke.ts
@@ -0,0 +1,39 @@
+import * as assert from 'assert';
+
+import { Code } from '../code';
+import { Edge } from '../edge';
+import { Node } from './base';
+
+/**
+ * Map of return codes of the callback. Each key is a return code,
+ * value is the target node that must be executed upon getting such return code.
+ */
+export interface IInvokeMap {
+  readonly [key: number]: Node;
+}
+
+/**
+ * This node invokes either external callback or intrinsic code and passes the
+ * execution to either a target from a `map` (if the return code matches one of
+ * registered in it), or to `otherwise` node.
+ */
+export class Invoke extends Node {
+  /**
+   * @param code  External callback or intrinsic code. Can be created with
+   *              `builder.code.*()` methods.
+   * @param map   Map from callback return codes to target nodes
+   */
+  constructor(public readonly code: Code, map: IInvokeMap) {
+    super('invoke_' + code.name);
+
+    Object.keys(map).forEach((mapKey) => {
+      const numKey: number = parseInt(mapKey, 10);
+      const targetNode = map[numKey]!;
+
+      assert.strictEqual(numKey, numKey | 0,
+        'Invoke\'s map keys must be integers');
+
+      this.addEdge(new Edge(targetNode, true, numKey, undefined));
+    });
+  }
+}