revert: single-binding ContextFrame representation; version 0.3.1

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@tiberjs/runner",
-  "version": "0.3.0",
+  "version": "0.3.1",
   "description": "Job-based structured concurrency, supervision, declarative task groups, and immutable execution context.",
   "type": "module",
   "main": "./dist/index.js",

src/execution/context/frame.ts

@@ -1,41 +1,11 @@
 import type { ContextEntry } from "./key.js";
 
-/** What a frame needs from its own bindings; `Map` satisfies it for many, one object for one. */
-interface Bindings {
-  has(key: PropertyKey): boolean;
-  get(key: PropertyKey): unknown;
-  keys(): Iterable<PropertyKey>;
-}
-
-/** The common case — one binding per frame — without a hash table. */
-class SingleBinding implements Bindings {
-  constructor(
-    private readonly key: PropertyKey,
-    private readonly value: unknown,
-  ) {}
-
-  has(key: PropertyKey): boolean {
-    return key === this.key;
-  }
-
-  get(key: PropertyKey): unknown {
-    return key === this.key ? this.value : undefined;
-  }
-
-  *keys(): Iterable<PropertyKey> {
-    yield this.key;
-  }
-}
-
-function bindingsOf(entries: readonly ContextEntry[]): Bindings {
-  if (entries.length === 1) {
-    const [key, value] = entries[0]!;
-    return new SingleBinding(key.id, value);
-  }
+function entryMap(entries: readonly ContextEntry[]): Map<PropertyKey, unknown> {
   const values = new Map<PropertyKey, unknown>();
   for (const [key, value] of entries) {
     values.set(key.id, value);
   }
+
   return values;
 }
 
@@ -49,9 +19,9 @@ function bindingsOf(entries: readonly ContextEntry[]): Bindings {
  */
 export class ContextFrame {
   readonly #parent: ContextFrame | null;
-  readonly #own: Bindings;
+  readonly #own: ReadonlyMap<PropertyKey, unknown>;
 
-  private constructor(parent: ContextFrame | null, own: Bindings) {
+  private constructor(parent: ContextFrame | null, own: ReadonlyMap<PropertyKey, unknown>) {
     this.#parent = parent;
     this.#own = own;
   }
@@ -61,7 +31,7 @@ export class ContextFrame {
 
   /** Create a root frame containing the supplied context bindings. */
   static from(entries: readonly ContextEntry[]): ContextFrame {
-    return entries.length === 0 ? ContextFrame.empty : new ContextFrame(null, bindingsOf(entries));
+    return entries.length === 0 ? ContextFrame.empty : new ContextFrame(null, entryMap(entries));
   }
 
   get(key: PropertyKey): unknown {
@@ -92,20 +62,18 @@ export class ContextFrame {
     if (keys.length === 0) {
       return this;
     }
-    if (keys.length === 1) {
-      const key = keys[0]!;
-      return new ContextFrame(this, new SingleBinding(key, values[key]));
-    }
+
     const own = new Map<PropertyKey, unknown>();
     for (const key of keys) {
-      own.set(key, values[key]);
+      own.set(key, (values as Record<PropertyKey, unknown>)[key]);
     }
+
     return new ContextFrame(this, own);
   }
 
   /** Return a child frame containing the supplied context bindings. */
   withEntries(entries: readonly ContextEntry[]): ContextFrame {
-    return entries.length === 0 ? this : new ContextFrame(this, bindingsOf(entries));
+    return entries.length === 0 ? this : new ContextFrame(this, entryMap(entries));
   }
 
   keys(): IterableIterator<PropertyKey> {