Refactor Instant.add() and subtract() into abstract operation

This operation will be reused in ZonedDateTime.add() and subtract() as well. See: #569
tc39 · Nov 3, 2020 · 72a02b8 · 72a02b8
1 parent 77bd78c
commit 72a02b8
Show file tree

Hide file tree

Showing 3 changed files with 50 additions and 40 deletions.
diff --git a/polyfill/lib/ecmascript.mjs b/polyfill/lib/ecmascript.mjs
@@ -2428,6 +2428,19 @@ export const ES = ObjectAssign({}, ES2020, {
     ES.RejectDuration(years, months, weeks, days, hours, minutes, seconds, milliseconds, microseconds, nanoseconds);
     return { years, months, weeks, days, hours, minutes, seconds, milliseconds, microseconds, nanoseconds };
   },
+  AddInstant: (epochNanoseconds, h, min, s, ms, µs, ns) => {
+    let sum = bigInt(0);
+    sum = sum.plus(bigInt(ns));
+    sum = sum.plus(bigInt(µs).multiply(1e3));
+    sum = sum.plus(bigInt(ms).multiply(1e6));
+    sum = sum.plus(bigInt(s).multiply(1e9));
+    sum = sum.plus(bigInt(min).multiply(60 * 1e9));
+    sum = sum.plus(bigInt(h).multiply(60 * 60 * 1e9));
+
+    const result = bigInt(epochNanoseconds).plus(sum);
+    ES.RejectInstantRange(result);
+    return result;
+  },
   RoundNumberToIncrement: (quantity, increment, mode) => {
     const quotient = quantity / increment;
     let round;

diff --git a/polyfill/lib/instant.mjs b/polyfill/lib/instant.mjs
@@ -58,18 +58,15 @@ export class Instant {
       nanoseconds
     } = ES.ToLimitedTemporalDuration(temporalDurationLike, ['years', 'months', 'weeks', 'days']);
     ES.RejectDurationSign(0, 0, 0, 0, hours, minutes, seconds, milliseconds, microseconds, nanoseconds);
-
-    let sum = bigInt(0);
-    sum = sum.plus(bigInt(nanoseconds));
-    sum = sum.plus(bigInt(microseconds).multiply(1e3));
-    sum = sum.plus(bigInt(milliseconds).multiply(1e6));
-    sum = sum.plus(bigInt(seconds).multiply(1e9));
-    sum = sum.plus(bigInt(minutes).multiply(60 * 1e9));
-    sum = sum.plus(bigInt(hours).multiply(60 * 60 * 1e9));
-
-    const ns = bigInt(GetSlot(this, EPOCHNANOSECONDS)).plus(sum);
-    ES.RejectInstantRange(ns);
-
+    const ns = ES.AddInstant(
+      GetSlot(this, EPOCHNANOSECONDS),
+      hours,
+      minutes,
+      seconds,
+      milliseconds,
+      microseconds,
+      nanoseconds
+    );
     const Construct = ES.SpeciesConstructor(this, Instant);
     const result = new Construct(bigIntIfAvailable(ns));
     if (!ES.IsTemporalInstant(result)) throw new TypeError('invalid result');
@@ -86,18 +83,15 @@ export class Instant {
       nanoseconds
     } = ES.ToLimitedTemporalDuration(temporalDurationLike, ['years', 'months', 'weeks', 'days']);
     ES.RejectDurationSign(0, 0, 0, 0, hours, minutes, seconds, milliseconds, microseconds, nanoseconds);
-
-    let sum = bigInt(0);
-    sum = sum.plus(bigInt(nanoseconds));
-    sum = sum.plus(bigInt(microseconds).multiply(1e3));
-    sum = sum.plus(bigInt(milliseconds).multiply(1e6));
-    sum = sum.plus(bigInt(seconds).multiply(1e9));
-    sum = sum.plus(bigInt(minutes).multiply(60 * 1e9));
-    sum = sum.plus(bigInt(hours).multiply(60 * 60 * 1e9));
-
-    const ns = bigInt(GetSlot(this, EPOCHNANOSECONDS)).minus(sum);
-    ES.RejectInstantRange(ns);
-
+    const ns = ES.AddInstant(
+      GetSlot(this, EPOCHNANOSECONDS),
+      -hours,
+      -minutes,
+      -seconds,
+      -milliseconds,
+      -microseconds,
+      -nanoseconds
+    );
     const Construct = ES.SpeciesConstructor(this, Instant);
     const result = new Construct(bigIntIfAvailable(ns));
     if (!ES.IsTemporalInstant(result)) throw new TypeError('invalid result');

diff --git a/spec/instant.html b/spec/instant.html
@@ -241,14 +241,7 @@ <h1>Temporal.Instant.prototype.add ( _temporalDurationLike_ )</h1>
         1. Perform ? RequireInternalSlot(_instant_, [[InitializedTemporalInstant]]).
         1. Let _duration_ be ? ToLimitedTemporalDuration(_temporalDurationLike_, « *"years"*, *"months"*, *"weeks"*, *"days"* »).
         1. Perform ? RejectDurationSign(_duration_.[[Years]], _duration_.[[Months]], _duration_.[[Weeks]], _duration_.[[Days]], _duration_.[[Hours]], _duration_.[[Minutes]], _duration_.[[Seconds]], _duration_.[[Milliseconds]], _duration_.[[Microseconds]], _duration_.[[Nanoseconds]]).
-        1. Let _ns_ be _instant_.[[Nanoseconds]] +
-            _duration_.[[Nanoseconds]] +
-            _duration_.[[Microseconds]] × 1000 +
-            _duration_.[[Milliseconds]] × 1,000,000 +
-            _duration_.[[Seconds]] × 1,000,000,000 +
-            _duration_.[[Minutes]] × 60,000,000,000 +
-            _duration_.[[Hours]] × 3,600,000,000,000.
-        1. Perform ? RejectInstant(_ns_).
+        1. Let _ns_ be ! AddInstant(_instant_.[[EpochNanoseconds]], _duration_.[[Hours]], _duration_.[[Minutes]], _duration_.[[Seconds]], _duration_.[[Milliseconds]], _duration_.[[Microseconds]], _duration_.[[Nanoseconds]]).
         1. Return ? CreateTemporalInstantFromInstance(_instant_, _ns_).
       </emu-alg>
     </emu-clause>
@@ -264,14 +257,7 @@ <h1>Temporal.Instant.prototype.subtract ( _temporalDurationLike_ )</h1>
         1. Perform ? RequireInternalSlot(_instant_, [[InitializedTemporalInstant]]).
         1. Let _duration_ be ? ToLimitedTemporalDuration(_temporalDurationLike_, « *"years"*, *"months"*, *"weeks"*, *"days"* »).
         1. Perform ? RejectDurationSign(_duration_.[[Years]], _duration_.[[Months]], _duration_.[[Weeks]], _duration_.[[Days]], _duration_.[[Hours]], _duration_.[[Minutes]], _duration_.[[Seconds]], _duration_.[[Milliseconds]], _duration_.[[Microseconds]], _duration_.[[Nanoseconds]]).
-        1. Let _ns_ be _instant_.[[Nanoseconds]] −
-            _duration_.[[Nanoseconds]] −
-            _duration_.[[Microseconds]] × 1000 −
-            _duration_.[[Milliseconds]] × 1,000,000 −
-            _duration_.[[Seconds]] × 1,000,000,000 −
-            _duration_.[[Minutes]] × 60,000,000,000 −
-            _duration_.[[Hours]] × 3,600,000,000,000.
-        1. Perform ? RejectInstant(_ns_).
+        1. Let _ns_ be ! AddInstant(_instant_.[[EpochNanoseconds]], −_duration_.[[Hours]], −_duration_.[[Minutes]], −_duration_.[[Seconds]], −_duration_.[[Milliseconds]], −_duration_.[[Microseconds]], −_duration_.[[Nanoseconds]]).
         1. Return ? CreateTemporalInstantFromInstance(_instant_, _ns_).
       </emu-alg>
     </emu-clause>
@@ -632,6 +618,23 @@ <h1>CompareEpochNanoseconds ( _epochNanosecondsOne_, _epochNanosecondsTwo_ )</h1
       </emu-alg>
     </emu-clause>
 
+    <emu-clause id="sec-temporal-addinstant" aoid="AddInstant">
+      <h1>AddInstant ( _epochNanoseconds_, _hours_, _minutes_, _seconds_, _milliseconds_, _microseconds_, _nanoseconds_ )</h1>
+      <p>
+        The abstract operation AddInstant adds a duration in various time units to a number of nanoseconds since the Unix epoch.
+      </p>
+      <emu-alg>
+        1. Let _result_ be _epochNanoseconds_ + _nanoseconds_ +
+            _microseconds_ × 1000 +
+            _milliseconds_ × 1,000,000 +
+            _seconds_ × 1,000,000,000 +
+            _minutes_ × 60,000,000,000 +
+            _hours_ × 3,600,000,000,000.
+        1. Perform ? RejectInstant(_result_).
+        1. Return _result_.
+      </emu-alg>
+    </emu-clause>
+
     <emu-clause id="sec-temporal-roundtemporalinstant" aoid="RoundTemporalInstant">
       <h1>RoundTemporalInstant ( _ns_, _increment_, _unit_, _roundingMode_ )</h1>
       <p>