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build/node_modules/prepack/lib/evaluators/ArrayExpression.js

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+"use strict";
+
+Object.defineProperty(exports, "__esModule", {
+  value: true
+});
+
+exports.default = function (ast, strictCode, env, realm) {
+  // 1. Let array be ArrayCreate(0).
+  var array = _singletons.Create.ArrayCreate(realm, 0);
+
+  // 2. Let len be the result of performing ArrayAccumulation for ElementList with arguments array and 0.
+  var elements = ast.elements || [];
+  var len = elements.length;
+  var nextIndex = 0;
+  for (var i = 0; i < len; i++) {
+    var elem = elements[i];
+    if (!elem) {
+      nextIndex++;
+      continue;
+    }
+
+    // ECMA262 12.2.5.2
+    if (elem.type === "SpreadElement") {
+      // 1. Let spreadRef be the result of evaluating AssignmentExpression.
+      var spreadRef = env.evaluate(elem.argument, strictCode);
+
+      // 2. Let spreadObj be ? GetValue(spreadRef).
+      var spreadObj = _singletons.Environment.GetValue(realm, spreadRef);
+
+      // 3. Let iterator be ? GetIterator(spreadObj).
+      var iterator = (0, _index2.GetIterator)(realm, spreadObj);
+
+      // 4. Repeat
+      while (true) {
+        // a. Let next be ? IteratorStep(iterator).
+        var next = (0, _iterator.IteratorStep)(realm, iterator);
+
+        // b. If next is false, return nextIndex.
+        if (next === false) break;
+
+        // c. Let nextValue be ? IteratorValue(next).
+        var nextValue = (0, _iterator.IteratorValue)(realm, next);
+
+        // d. Let status be CreateDataProperty(array, ToString(ToUint32(nextIndex)), nextValue).
+        var status = _singletons.Create.CreateDataProperty(realm, array, new _index.StringValue(realm, nextIndex++ + ""), nextValue);
+
+        // e. Assert: status is true.
+        (0, _invariant2.default)(status === true);
+
+        // f. Let nextIndex be nextIndex + 1.
+      }
+    } else {
+      // Redundant steps.
+      // 1. Let postIndex be the result of performing ArrayAccumulation for ElementList with arguments array and nextIndex.
+      // 2. ReturnIfAbrupt(postIndex).
+      // 3. Let padding be the ElisionWidth of Elision; if Elision is not present, use the numeric value zero.
+
+      // 4. Let initResult be the result of evaluating AssignmentExpression.
+      var initResult = env.evaluate(elem, strictCode);
+
+      // 5. Let initValue be ? GetValue(initResult).
+      var initValue = _singletons.Environment.GetValue(realm, initResult);
+
+      // 6. Let created be CreateDataProperty(array, ToString(ToUint32(postIndex+padding)), initValue).
+      var created = _singletons.Create.CreateDataProperty(realm, array, new _index.StringValue(realm, nextIndex++ + ""), initValue);
+
+      // 7. Assert: created is true.
+      (0, _invariant2.default)(created === true, "expected data property creation");
+    }
+  }
+
+  // Not necessary since we propagate completions with exceptions.
+  // 3. ReturnIfAbrupt(len).
+
+  // 4. Perform Set(array, "length", ToUint32(len), false).
+  _singletons.Properties.Set(realm, array, "length", new _index.NumberValue(realm, nextIndex), false);
+
+  // 5. NOTE: The above Set cannot fail because of the nature of the object returned by ArrayCreate.
+
+  // 6. Return array.
+  return array;
+};
+
+var _index = require("../values/index.js");
+
+var _index2 = require("../methods/index.js");
+
+var _invariant = require("../invariant.js");
+
+var _invariant2 = _interopRequireDefault(_invariant);
+
+var _iterator = require("../methods/iterator.js");
+
+var _singletons = require("../singletons.js");
+
+function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }
+//# sourceMappingURL=ArrayExpression.js.map