Rename directory "engines" to "languages"

languages/worker-constants.ts

@@ -0,0 +1,76 @@
+import { StepExecutionResult } from "./types";
+import * as E from "./worker-errors";
+
+/** Types of requests the worker handles */
+export type WorkerRequestData =
+  | {
+      type: "Init";
+      params?: null;
+    }
+  | {
+      type: "Reset";
+      params?: null;
+    }
+  | {
+      type: "Prepare";
+      params: { code: string; input: string };
+    }
+  | {
+      type: "UpdateBreakpoints";
+      params: { points: number[] };
+    }
+  | {
+      type: "ValidateCode";
+      params: { code: string };
+    }
+  | {
+      type: "Execute";
+      params: { interval: number };
+    }
+  | {
+      type: "ExecuteStep";
+      params?: null;
+    }
+  | {
+      type: "Pause";
+      params?: null;
+    };
+
+/** Kinds of acknowledgement responses the worker can send  */
+export type WorkerAckType =
+  | "init" // on initialization
+  | "reset" // on state reset
+  | "bp-update" // on updating breakpoints
+  | "prepare" // on preparing for execution
+  | "pause"; // on pausing execution
+
+/** Errors associated with each response ack type */
+export type WorkerAckError = {
+  init: undefined;
+  reset: undefined;
+  "bp-update": undefined;
+  prepare: E.WorkerParseError;
+  pause: undefined;
+};
+
+/** Types of responses the worker can send */
+export type WorkerResponseData<RS, A extends WorkerAckType> =
+  /** Ack for one-off requests, optionally containing error occured (if any) */
+  | {
+      type: "ack";
+      data: A;
+      error?: WorkerAckError[A];
+    }
+  /** Result of code validation, containing parsing error (if any) */
+  | {
+      type: "validate";
+      error?: E.WorkerParseError;
+    }
+  /** Response containing step execution result, and runtime error (if any) */
+  | {
+      type: "result";
+      data: StepExecutionResult<RS>;
+      error?: E.WorkerRuntimeError;
+    }
+  /** Response indicating a bug in worker/engine logic */
+  | { type: "error"; error: E.WorkerError };