Implement types and WIP pipe fittings

Author: cliffhall

src/types/pipe.ts

@@ -0,0 +1,67 @@
+import { PipeMessage } from "./message";
+
+/**
+ * Pipe Fitting Interface.
+ *
+ * An `IPipeFitting<` can be connected to other
+ * `IPipeFitting`s, forming a Pipeline.
+ * `Messages`s are written to one end of a
+ * Pipeline by some client code. The messages are then
+ * transferred in synchronous fashion from one fitting to
+ * the next.
+ */
+export interface IPipeFitting {
+  /**
+   * Connect another Pipe Fitting to the output.
+   *`
+   * Fittings connect and write to
+   * other fittings in a one way synchronous
+   * chain, as water typically flows one direction
+   * through a physical pipes.ts.`
+   *
+   * @return Boolean true if no other fitting was already connected.
+   */
+  connect(output: IPipeFitting): boolean;
+
+  /**
+   * Disconnect the Pipe Fitting connected to the output.
+   *`
+   * This disconnects the output fitting, returning a
+   * reference to it. If you were splicing another fitting
+   * into a pipeline, you need to keep (at least briefly)
+   * a reference to both sides of the pipeline in order to
+   * connect them to the input and output of whatever
+   * fitting that you're splicing in.`
+   *
+   * @return IPipeFitting the now disconnected output fitting
+   */
+  disconnect(): IPipeFitting | null;
+
+  /**
+   * Write the message to the output Pipe Fitting.
+   *`
+   * There may be subsequent filters and tees
+   * (which also implement this interface), that the
+   * fitting is writing to, and so a message
+   * may branch and arrive in different forms at
+   * different endpoints. `
+   *`
+   * If any fitting in the chain returns false
+   * from this method, then the client who originally
+   * wrote into the pipes.ts can take action, such as
+   * rolling back changes.`
+   */
+  write(message: PipeMessage): boolean;
+}
+
+/**
+ * Pipe Aware interface.
+ *
+ * Can be implemented by any PureMVC Core that wishes
+ * to communicate with other Cores using the Pipes
+ * utility.
+ */
+export interface IPipeAware {
+  acceptInputPipe(name: string, pipe: IPipeFitting): void;
+  acceptOutputPipe(name: string, pipe: IPipeFitting): void;
+}