Merge commit '6e92d2345e8231a44556ce7d416451f5f3e6c398' as 'engine262'

2026-08-19 00:31:06 +00:00 · 2026-03-27 10:07:29 +05:30
parent 8f26db5a1f 6e92d2345e
commit b42a69d9f8
433 changed files with 90478 additions and 0 deletions
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+import { Q } from '../completion.mts';
+import { Evaluate, type ValueEvaluator } from '../evaluator.mts';
+import { Value } from '../value.mts';
+import type { ParseNode } from '../parser/ParseNode.mts';
+import { GetValue } from '#self';
+
+/** https://tc39.es/ecma262/#sec-binary-logical-operators-runtime-semantics-evaluation */
+//   CoalesceExpression :
+//     CoalesceExpressionHead `??` BitwiseORExpression
+export function* Evaluate_CoalesceExpression({ CoalesceExpressionHead, BitwiseORExpression }: ParseNode.CoalesceExpression): ValueEvaluator {
+  // 1. Let lref be the result of evaluating |CoalesceExpressionHead|.
+  const lref = Q(yield* Evaluate(CoalesceExpressionHead));
+  // 2. Let lval be ? GetValue(lref).
+  const lval = Q(yield* GetValue(lref));
+  // 3. If lval is *undefined* or *null*,
+  if (lval === Value.undefined || lval === Value.null) {
+    // a. Let rref be the result of evaluating |BitwiseORExpression|.
+    const rref = Q(yield* Evaluate(BitwiseORExpression));
+    // b. Return ? GetValue(rref).
+    return Q(yield* GetValue(rref));
+  }
+  // 4. Otherwise, return lval.
+  return lval;
+}