perf(engine): trim Date shim slot fan-out and binary-search timezone lookup

source/units/Goccia.Shims.pas

@@ -438,7 +438,7 @@ implementation
         'const __GocciaDateIsObject = (value: any): boolean =>'#10 +
         '  (typeof value === "object" && value !== null) || typeof value === "function";'#10 +
         'const __GocciaDateHasSlot = (date: any): boolean =>'#10 +
-        '  __GocciaDateIsObject(date) && __GocciaDateSlots.has(date);'#10 +
+        '  __GocciaDateSlots.get(date) !== undefined;'#10 +
         'const __GocciaDateOrdinaryToPrimitive = (object: any, hint: string): any => {'#10 +
         '  const first: string = hint === "string" ? "toString" : "valueOf";'#10 +
         '  const second: string = hint === "string" ? "valueOf" : "toString";'#10 +
@@ -480,6 +480,7 @@ implementation
         '    (year < 0 ? "-" : "+") + __GocciaDatePad(year, 6);'#10 +
         'const __GocciaDateOffsetString = (offset: string): string => offset.replace(":", "");'#10 +
         'const __GocciaDateFromSingleArgument = (value: any): number => {'#10 +
+        '  if (typeof value === "number") return __GocciaDateTimeClip(value);'#10 +
         '  if (__GocciaDateHasSlot(value)) return __GocciaDateGetSlot(value);'#10 +
         '  const primitive: any = __GocciaDateToPrimitive(value);'#10 +
         '  return typeof primitive === "string" ? parseDateStringToEpoch(primitive) : __GocciaDateTimeClip(primitive);'#10 +
@@ -494,12 +495,16 @@ implementation
         '  } catch (e) {}'#10 +
         '  return __GocciaDateClass.prototype;'#10 +
         '};'#10 +
+        '// A Date slot only ever stores a number (never undefined), so a missing'#10 +
+        '// entry reads back as undefined and doubles as the brand check. This keeps'#10 +
+        '// the hot accessors to a single WeakMap lookup instead of has()+get().'#10 +
         'const __GocciaDateRequire = (date: any): void => {'#10 +
-        '  if (!__GocciaDateHasSlot(date)) throw new TypeError("Date object expected");'#10 +
+        '  if (__GocciaDateSlots.get(date) === undefined) throw new TypeError("Date object expected");'#10 +
         '};'#10 +
         'const __GocciaDateGetSlot = (date: any): number => {'#10 +
-        '  __GocciaDateRequire(date);'#10 +
-        '  return __GocciaDateSlots.get(date);'#10 +
+        '  const value: any = __GocciaDateSlots.get(date);'#10 +
+        '  if (value === undefined) throw new TypeError("Date object expected");'#10 +
+        '  return value;'#10 +
         '};'#10 +
         'const __GocciaDateSetSlot = (date: any, value: number): number => {'#10 +
         '  __GocciaDateSlots.set(date, value);'#10 +
@@ -557,8 +562,8 @@         'const __GocciaDateClass = class Date {'#10 +
         '  static #get(date: any): number { return __GocciaDateGetSlot(date); }'#10 +
         '  static #set(date: any, value: number): number { return __GocciaDateSetSlot(date, value); }'#10 +
         '  static #valid(date: any): boolean { return Number.isFinite(Date.#get(date)); }'#10 +
-        '  static #local(date: any): any { return Date.#valid(date) ? new Temporal.ZonedDateTime(BigInt(Date.#get(date)) * 1000000n, Temporal.Now.timeZoneId()) : null; }'#10 +
-        '  static #utc(date: any): any { return Date.#valid(date) ? new Temporal.ZonedDateTime(BigInt(Date.#get(date)) * 1000000n, "UTC") : null; }'#10 +
+        '  static #local(date: any): any { const ms: number = Date.#get(date); return Number.isFinite(ms) ? new Temporal.ZonedDateTime(BigInt(ms) * 1000000n, Temporal.Now.timeZoneId()) : null; }'#10 +
+        '  static #utc(date: any): any { const ms: number = Date.#get(date); return Number.isFinite(ms) ? new Temporal.ZonedDateTime(BigInt(ms) * 1000000n, "UTC") : null; }'#10 +
         '  getTime(): number { return __GocciaDateGetSlot(this); }'#10 +
         '  valueOf(): number { return __GocciaDateGetSlot(this); }'#10 +
         '  [Symbol.toPrimitive](hint: string): any {'#10 +

source/units/Goccia.Temporal.TimeZone.pas

@@ -1093,12 +1093,26 @@ function IsUTCPrimaryEquivalent(const ATimeZone: string): Boolean;
 function IsSupportedCanonicalTimeZoneIdentifier(const ATimeZone: string): Boolean;
 var
   AvailableTimeZones: TTemporalTimeZoneIdentifierArray;
-  Index: Integer;
+  Low, High, Mid, Cmp: Integer;
 begin
+  // GetAvailablePrimaryTimeZoneIdentifiers returns a list sorted ascending by
+  // CompareStr (see SortTimeZoneIdentifiers). Probe it with a binary search
+  // instead of an O(n) scan: this runs on every ZonedDateTime time-zone
+  // canonicalization, and the available-zone list has several hundred entries.
   AvailableTimeZones := GetAvailablePrimaryTimeZoneIdentifiers;
-  for Index := 0 to Length(AvailableTimeZones) - 1 do
-    if AvailableTimeZones[Index] = ATimeZone then
-      Exit(True);
+  Low := 0;
+  High := Length(AvailableTimeZones) - 1;
+  while Low <= High do
+  begin
+    Mid := Low + (High - Low) div 2;
+    Cmp := CompareStr(AvailableTimeZones[Mid], ATimeZone);
+    if Cmp = 0 then
+      Exit(True)
+    else if Cmp < 0 then
+      Low := Mid + 1
+    else
+      High := Mid - 1;
+  end;
 
   Result := False;
 end;

tests/built-ins/Date/methods.js

@@ -250,6 +250,34 @@ describe("Date methods", () => {
     }
   });
 
+  test("slot-requiring methods reject a plain non-Date object receiver", () => {
+    const slotMethods = [
+      "getTime",
+      "valueOf",
+      "getFullYear",
+      "getUTCFullYear",
+      "getTimezoneOffset",
+      "setTime",
+      "setFullYear",
+      "toISOString",
+      "toString",
+    ];
+
+    for (const method of slotMethods) {
+      const fn = Date.prototype[method];
+      expect(() => fn.call({})).toThrow(TypeError);
+      expect(() => fn.call(Object.create(Date.prototype))).toThrow(TypeError);
+    }
+  });
+
+  test("constructor reads the time value from a Date argument and clips numbers", () => {
+    const source = new Date(1718451045123);
+    expect(new Date(source).getTime()).toBe(1718451045123);
+    expect(new Date(2000).getTime()).toBe(2000);
+    expect(Number.isNaN(new Date(NaN).getTime())).toBe(true);
+    expect(Number.isNaN(new Date(NaN).getTimezoneOffset())).toBe(true);
+  });
+
   test("toJSON remains generic for object receivers", () => {
     const receiver = {
       valueOf() { return 1; },

tests/built-ins/Temporal/ZonedDateTime/constructor.js

@@ -24,6 +24,21 @@ describe.runIf(isTemporal)("Temporal.ZonedDateTime constructor", () => {
     expect(zdt.calendarId).toBe("iso8601");
   });
 
+  test("canonical named time zones are accepted and preserved", () => {
+    const zones = [
+      "Africa/Cairo",
+      "America/Los_Angeles",
+      "Asia/Tokyo",
+      "Europe/London",
+      "Pacific/Auckland",
+      "UTC",
+    ];
+    for (const id of zones) {
+      expect(new Temporal.ZonedDateTime(0n, id).timeZoneId).toBe(id);
+    }
+    expect(() => new Temporal.ZonedDateTime(0n, "Not/AZone")).toThrow(RangeError);
+  });
+
   test("constructor stores non-ISO calendarId", () => {
     const zdt = new Temporal.ZonedDateTime(0n, "Europe/Madrid", "gregory");
     expect(zdt.calendarId).toBe("gregory");