prepack/lib/evaluators/AssignmentExpression.js

Execute a JS bundle, serialize global state and side effects to a snapshot that can be quickly restored.

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = _default;

var _index = require("../values/index.js");

var _environment = require("../environment.js");

var _index2 = require("../methods/index.js");

var _singletons = require("../singletons.js");

var _invariant = _interopRequireDefault(require("../invariant.js"));

var _BinaryExpression = require("./BinaryExpression.js");

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

/**
 * Copyright (c) 2017-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */
// ECMA262 12.15 Assignment Operators
function _default(ast, strictCode, env, realm) {
  if (!ast.hasOwnProperty("operator") || ast.operator === null) throw Error("Unexpected AST form");
  let LeftHandSideExpression = ast.left;
  let AssignmentExpression = ast.right;
  let AssignmentOperator = ast.operator; // AssignmentExpression : LeftHandSideExpression = AssignmentExpression

  if (AssignmentOperator === "=") {
    // 1. If LeftHandSideExpression is neither an ObjectLiteral nor an ArrayLiteral, then
    //
    // The spec assumes we haven't yet distinguished between literals and
    // patterns, but our parser does that work for us. That means we check for
    // "*Pattern" instead of "*Literal" like the spec text suggests.
    if (LeftHandSideExpression.type !== "ObjectPattern" && LeftHandSideExpression.type !== "ArrayPattern") {
      // a. Let lref be the result of evaluating LeftHandSideExpression.
      let lref = env.evaluate(LeftHandSideExpression, strictCode); // b. ReturnIfAbrupt(lref). -- Not neccessary
      // c. Let rref be the result of evaluating AssignmentExpression.

      let rref = env.evaluate(AssignmentExpression, strictCode); // d. Let rval be ? GetValue(rref).

      let rval = _singletons.Environment.GetValue(realm, rref); // e. If IsAnonymousFunctionDefinition(AssignmentExpression) and IsIdentifierRef of LeftHandSideExpression are both true, then


      if ((0, _index2.IsAnonymousFunctionDefinition)(realm, AssignmentExpression) && (0, _index2.IsIdentifierRef)(realm, LeftHandSideExpression)) {
        (0, _invariant.default)(rval instanceof _index.ObjectValue); // i. Let hasNameProperty be ? HasOwnProperty(rval, "name").

        let hasNameProperty = (0, _index2.HasOwnProperty)(realm, rval, "name"); // ii. If hasNameProperty is false, perform SetFunctionName(rval, GetReferencedName(lref)).

        if (!hasNameProperty) {
          (0, _invariant.default)(lref instanceof _environment.Reference);

          _singletons.Functions.SetFunctionName(realm, rval, _singletons.Environment.GetReferencedName(realm, lref));
        }
      } // f. Perform ? PutValue(lref, rval).


      _singletons.Properties.PutValue(realm, lref, rval); // g. Return rval.


      return rval;
    } // 2. Let assignmentPattern be the parse of the source text corresponding to LeftHandSideExpression using AssignmentPattern[?Yield] as the goal symbol.


    let assignmentPattern = LeftHandSideExpression; // 3. Let rref be the result of evaluating AssignmentExpression.

    let rref = env.evaluate(AssignmentExpression, strictCode); // 4. Let rval be ? GetValue(rref).

    let rval = _singletons.Environment.GetValue(realm, rref); // 5. Let status be the result of performing DestructuringAssignmentEvaluation of assignmentPattern using rval as the argument.


    (0, _index2.DestructuringAssignmentEvaluation)(realm, assignmentPattern, rval, strictCode, env); // 6. ReturnIfAbrupt(status).
    // 7. Return rval.

    return rval;
  } // AssignmentExpression : LeftHandSideExpression AssignmentOperator AssignmentExpression
  // 1. Let lref be the result of evaluating LeftHandSideExpression.


  let lref = env.evaluate(LeftHandSideExpression, strictCode); // 2. Let lval be ? GetValue(lref).

  let lval = _singletons.Environment.GetValue(realm, lref); // 3. Let rref be the result of evaluating AssignmentExpression.


  let rref = env.evaluate(AssignmentExpression, strictCode); // 4. Let rval be ? GetValue(rref).

  let rval = _singletons.Environment.GetValue(realm, rref); // 5. Let op be the @ where AssignmentOperator is @=.


  let op = AssignmentOperator.slice(0, -1); // 6. Let r be the result of applying op to lval and rval as if evaluating the expression lval op rval.

  let r = _singletons.Environment.GetValue(realm, (0, _BinaryExpression.computeBinary)(realm, op, lval, rval, ast.left.loc, ast.right.loc)); // 7. Perform ? PutValue(lref, r).


  _singletons.Properties.PutValue(realm, lref, r); // 8. Return r.


  return r;
}
//# sourceMappingURL=AssignmentExpression.js.map