asciidisco.com/build/node_modules/prepack/lib/evaluators/ForOfStatement.js

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.InternalGetResultValue = InternalGetResultValue;
exports.LoopContinues = LoopContinues;
exports.ForInOfHeadEvaluation = ForInOfHeadEvaluation;
exports.ForInOfBodyEvaluation = ForInOfBodyEvaluation;

exports.default = function (ast, strictCode, env, realm, labelSet) {
  var left = ast.left,
      right = ast.right,
      body = ast.body;


  try {
    if (left.type === "VariableDeclaration") {
      if (left.kind === "var") {
        // for (var ForBinding o fAssignmentExpression) Statement
        // 1. Let keyResult be the result of performing ? ForIn/OfHeadEvaluation(« », AssignmentExpression, iterate).
        var keyResult = ForInOfHeadEvaluation(realm, env, [], right, "iterate", strictCode);
        (0, _invariant2.default)(keyResult instanceof _index.ObjectValue);

        // 2. Return ? ForIn/OfBodyEvaluation(ForBinding, Statement, keyResult, varBinding, labelSet).
        return ForInOfBodyEvaluation(realm, env, left.declarations[0].id, body, keyResult, "varBinding", labelSet, strictCode);
      } else {
        // for (ForDeclaration of AssignmentExpression) Statement
        // 1. Let keyResult be the result of performing ? ForIn/OfHeadEvaluation(BoundNames of ForDeclaration, AssignmentExpression, iterate).
        var _keyResult = ForInOfHeadEvaluation(realm, env, _singletons.Environment.BoundNames(realm, left), right, "iterate", strictCode);
        (0, _invariant2.default)(_keyResult instanceof _index.ObjectValue);

        // 2. Return ? ForIn/OfBodyEvaluation(ForDeclaration, Statement, keyResult, lexicalBinding, labelSet).
        return ForInOfBodyEvaluation(realm, env, left, body, _keyResult, "lexicalBinding", labelSet, strictCode);
      }
    } else {
      // for (LeftHandSideExpression of AssignmentExpression) Statement
      // 1. Let keyResult be the result of performing ? ForIn/OfHeadEvaluation(« », AssignmentExpression, iterate).
      var _keyResult2 = ForInOfHeadEvaluation(realm, env, [], right, "iterate", strictCode);
      (0, _invariant2.default)(_keyResult2 instanceof _index.ObjectValue);

      // 2. Return ? ForIn/OfBodyEvaluation(LeftHandSideExpression, Statement, keyResult, assignment, labelSet).
      return ForInOfBodyEvaluation(realm, env, left, body, _keyResult2, "assignment", labelSet, strictCode);
    }
  } catch (e) {
    if (e instanceof _completions.BreakCompletion) {
      if (!e.target) return (0, _index2.UpdateEmpty)(realm, e, realm.intrinsics.undefined).value;
    }
    throw e;
  }
};

var _errors = require("../errors.js");

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

var _completions = require("../completions.js");

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

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

var _invariant2 = _interopRequireDefault(_invariant);

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

var _singletons = require("../singletons.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.
 */

function InternalGetResultValue(realm, result) {
  if (result instanceof _completions.AbruptCompletion) {
    return result.value;
  } else {
    return result;
  }
}

// ECMA262 13.7.1.2
function LoopContinues(realm, completion, labelSet) {
  // 1. If completion.[[Type]] is normal, return true.
  if (completion instanceof _index.Value) return true;
  (0, _invariant2.default)(completion instanceof _completions.AbruptCompletion);

  // 2. If completion.[[Type]] is not continue, return false.
  if (!(completion instanceof _completions.ContinueCompletion)) return false;

  // 3. If completion.[[Target]] is empty, return true.
  if (!completion.target) return true;

  // 4. If completion.[[Target]] is an element of labelSet, return true.
  if (labelSet != null && labelSet.indexOf(completion.target) >= 0) return true;

  // 5. Return false.
  return false;
}

// ECMA262 13.7.5.10
function BindingInstantiation(realm, ast, env) {
  // ast = ForDeclaration : LetOrConst ForBinding

  // 1. Let envRec be environment's EnvironmentRecord.
  var envRec = env.environmentRecord;

  // 2. Assert: envRec is a declarative Environment Record.
  (0, _invariant2.default)(envRec instanceof _environment.DeclarativeEnvironmentRecord);

  // 3. For each element name of the BoundNames of ForBinding do
  var _iteratorNormalCompletion = true;
  var _didIteratorError = false;
  var _iteratorError = undefined;

  try {
    for (var _iterator = _singletons.Environment.BoundNames(realm, ast)[Symbol.iterator](), _step; !(_iteratorNormalCompletion = (_step = _iterator.next()).done); _iteratorNormalCompletion = true) {
      var name = _step.value;

      // a. If IsConstantDeclaration of LetOrConst is true, then
      if (ast.kind === "const") {
        // i. Perform ! envRec.CreateImmutableBinding(name, true).
        envRec.CreateImmutableBinding(name, true);
      } else {
        // b.
        // i. Perform ! envRec.CreateMutableBinding(name, false).
        envRec.CreateMutableBinding(name, false);
      }
    }
  } catch (err) {
    _didIteratorError = true;
    _iteratorError = err;
  } finally {
    try {
      if (!_iteratorNormalCompletion && _iterator.return) {
        _iterator.return();
      }
    } finally {
      if (_didIteratorError) {
        throw _iteratorError;
      }
    }
  }
}

// ECMA262 13.7.5.12
function ForInOfHeadEvaluation(realm, env, TDZnames, expr, iterationKind, strictCode) {
  // 1. Let oldEnv be the running execution context's LexicalEnvironment.
  var oldEnv = realm.getRunningContext().lexicalEnvironment;

  // 2. If TDZnames is not an empty List, then
  if (TDZnames.length) {
    // a. Assert: TDZnames has no duplicate entries.

    // b. Let TDZ be NewDeclarativeEnvironment(oldEnv).
    var TDZ = _singletons.Environment.NewDeclarativeEnvironment(realm, oldEnv);

    // c. Let TDZEnvRec be TDZ's EnvironmentRecord.
    var TDZEnvRec = TDZ.environmentRecord;

    // d. For each string name in TDZnames, do
    var _iteratorNormalCompletion2 = true;
    var _didIteratorError2 = false;
    var _iteratorError2 = undefined;

    try {
      for (var _iterator2 = TDZnames[Symbol.iterator](), _step2; !(_iteratorNormalCompletion2 = (_step2 = _iterator2.next()).done); _iteratorNormalCompletion2 = true) {
        var name = _step2.value;

        // i. Perform ! TDZEnvRec.CreateMutableBinding(name, false).
        TDZEnvRec.CreateMutableBinding(name, false);
      }

      // e. Set the running execution context's LexicalEnvironment to TDZ.
    } catch (err) {
      _didIteratorError2 = true;
      _iteratorError2 = err;
    } finally {
      try {
        if (!_iteratorNormalCompletion2 && _iterator2.return) {
          _iterator2.return();
        }
      } finally {
        if (_didIteratorError2) {
          throw _iteratorError2;
        }
      }
    }

    realm.getRunningContext().lexicalEnvironment = TDZ;
    env = TDZ;
  }

  var exprRef = void 0;
  try {
    // 3. Let exprRef be the result of evaluating expr.
    exprRef = env.evaluate(expr, strictCode);
  } finally {
    // 4. Set the running execution context's LexicalEnvironment to oldEnv.
    var lexEnv = realm.getRunningContext().lexicalEnvironment;
    if (lexEnv !== oldEnv) realm.onDestroyScope(lexEnv);
    realm.getRunningContext().lexicalEnvironment = oldEnv;
  }
  env = oldEnv;

  // 5. Let exprValue be ? GetValue(exprRef).
  var exprValue = _singletons.Environment.GetValue(realm, exprRef);

  // 6. If iterationKind is enumerate, then
  if (iterationKind === "enumerate") {
    // a. If exprValue.[[Value]] is null or undefined, then
    if (exprValue instanceof _index.NullValue || exprValue instanceof _index.UndefinedValue) {
      // i. Return Completion{[[Type]]: break, [[Value]]: empty, [[Target]]: empty}.
      throw new _completions.BreakCompletion(realm.intrinsics.empty, expr.loc, undefined);
    }

    // b. Let obj be ToObject(exprValue).
    var obj = _singletons.To.ToObjectPartial(realm, exprValue);

    // c. Return ? EnumerateObjectProperties(obj).
    if (obj.isPartialObject() || obj instanceof _index.AbstractObjectValue) {
      return obj;
    } else {
      return _singletons.Properties.EnumerateObjectProperties(realm, obj);
    }
  } else {
    // 8. Else,
    // 1. Assert: iterationKind is iterate.
    (0, _invariant2.default)(iterationKind === "iterate", "expected iterationKind to be iterate");

    if (exprValue instanceof _index.AbstractValue) {
      var error = new _errors.CompilerDiagnostic("for of loops over unknown collections are not yet supported", expr.loc, "PP0014", "FatalError");
      realm.handleError(error);
      throw new _errors.FatalError();
    }

    // 1. Return ? GetIterator(exprValue).
    return (0, _index2.GetIterator)(realm, exprValue);
  }
}

// ECMA262 13.7.5.13
function ForInOfBodyEvaluation(realm, env, lhs, stmt, iterator, lhsKind, labelSet, strictCode) {
  // 1. Let oldEnv be the running execution context's LexicalEnvironment.
  var oldEnv = realm.getRunningContext().lexicalEnvironment;

  // 2. Let V be undefined.
  var V = realm.intrinsics.undefined;

  // 3. Let destructuring be IsDestructuring of lhs.
  var destructuring = _singletons.Environment.IsDestructuring(lhs);

  // 4. If destructuring is true and if lhsKind is assignment, then
  if (destructuring && lhsKind === "assignment") {
    // a. Assert: lhs is a LeftHandSideExpression.
    (0, _invariant2.default)(lhs.type !== "VariableDeclaration");

    // b. Let assignmentPattern be the parse of the source text corresponding to lhs using AssignmentPattern as the goal symbol.
  }

  // 5. Repeat
  while (true) {
    // a. Let nextResult be ? IteratorStep(iterator).
    var nextResult = (0, _index2.IteratorStep)(realm, iterator);

    // b. If nextResult is false, return NormalCompletion(V).
    if (!nextResult) return V;

    // c. Let nextValue be ? IteratorValue(nextResult).
    var nextValue = (0, _index2.IteratorValue)(realm, nextResult);

    // d. If lhsKind is either assignment or varBinding, then
    var iterationEnv = void 0;
    var lhsRef = void 0;
    if (lhsKind === "assignment" || lhsKind === "varBinding") {
      // i. If destructuring is false, then
      if (!destructuring) {
        // 1. Let lhsRef be the result of evaluating lhs. (It may be evaluated repeatedly.)
        lhsRef = env.evaluateCompletion(lhs, strictCode);
      }
    } else {
      // e. Else,
      // i. Assert: lhsKind is lexicalBinding.
      (0, _invariant2.default)(lhsKind === "lexicalBinding", "expected lhsKind to be lexicalBinding");
      (0, _invariant2.default)(lhs.type === "VariableDeclaration");

      // ii. Assert: lhs is a ForDeclaration.

      // iii. Let iterationEnv be NewDeclarativeEnvironment(oldEnv).
      iterationEnv = _singletons.Environment.NewDeclarativeEnvironment(realm, oldEnv);

      // iv. Perform BindingInstantiation for lhs passing iterationEnv as the argument.
      BindingInstantiation(realm, lhs, iterationEnv);

      // v. Set the running execution context's LexicalEnvironment to iterationEnv.
      realm.getRunningContext().lexicalEnvironment = iterationEnv;
      env = iterationEnv;

      // vi. If destructuring is false, then
      if (!destructuring) {
        var names = _singletons.Environment.BoundNames(realm, lhs);

        // 1. Assert: lhs binds a single name.
        (0, _invariant2.default)(names.length === 1, "expected single name");

        // 2. Let lhsName be the sole element of BoundNames of lhs.
        var lhsName = names[0];

        // 3. Let lhsRef be ! ResolveBinding(lhsName).
        lhsRef = _singletons.Environment.ResolveBinding(realm, lhsName, strictCode);
      }
    }

    // f. If destructuring is false, then
    var status = void 0;
    try {
      if (!destructuring) {
        // i. If lhsRef is an abrupt completion, then
        if (lhsRef instanceof _completions.AbruptCompletion) {
          // 1. Let status be lhsRef.
          status = lhsRef;
        } else if (lhsKind === "lexicalBinding") {
          // ii. Else if lhsKind is lexicalBinding, then
          // 1. Let status be InitializeReferencedBinding(lhsRef, nextValue).
          (0, _invariant2.default)(lhsRef instanceof _environment.Reference);
          status = _singletons.Environment.InitializeReferencedBinding(realm, lhsRef, nextValue);
        } else {
          // iii. Else,
          // 1. Let status be PutValue(lhsRef, nextValue).
          (0, _invariant2.default)(lhsRef !== undefined);
          status = _singletons.Properties.PutValue(realm, lhsRef, nextValue);
        }
      } else {
        // g. Else,
        // i. If lhsKind is assignment, then
        if (lhsKind === "assignment") {
          (0, _invariant2.default)(lhs.type === "ArrayPattern" || lhs.type === "ObjectPattern");

          // 1. Let status be the result of performing DestructuringAssignmentEvaluation of assignmentPattern using nextValue as the argument.
          status = (0, _index2.DestructuringAssignmentEvaluation)(realm, lhs, nextValue, strictCode, iterationEnv || env);
        } else if (lhsKind === "varBinding") {
          // ii. Else if lhsKind is varBinding, then
          // 1. Assert: lhs is a ForBinding.

          // 2. Let status be the result of performing BindingInitialization for lhs passing nextValue and undefined as the arguments.
          status = _singletons.Environment.BindingInitialization(realm, lhs, nextValue, strictCode, undefined);
        } else {
          // iii. Else,
          // 1. Assert: lhsKind is lexicalBinding.
          (0, _invariant2.default)(lhsKind === "lexicalBinding");

          // 2. Assert: lhs is a ForDeclaration.

          // 3. Let status be the result of performing BindingInitialization for lhs passing nextValue and iterationEnv as arguments.
          (0, _invariant2.default)(iterationEnv !== undefined);
          status = _singletons.Environment.BindingInitialization(realm, lhs, nextValue, strictCode, iterationEnv);
        }
      }
    } catch (e) {
      if (e instanceof _completions.AbruptCompletion) {
        status = e;
      } else {
        throw e;
      }
    }

    // h. If status is an abrupt completion, then
    if (status instanceof _completions.AbruptCompletion) {
      // i. Set the running execution context's LexicalEnvironment to oldEnv.
      realm.getRunningContext().lexicalEnvironment = oldEnv;

      // ii. Return ? IteratorClose(iterator, status).
      throw (0, _index2.IteratorClose)(realm, iterator, status);
    }

    // i. Let result be the result of evaluating stmt.
    var result = env.evaluateCompletion(stmt, strictCode);
    (0, _invariant2.default)(result instanceof _index.Value || result instanceof _completions.AbruptCompletion);

    // j. Set the running execution context's LexicalEnvironment to oldEnv.

    var lexEnv = realm.getRunningContext().lexicalEnvironment;
    if (lexEnv !== oldEnv) realm.onDestroyScope(lexEnv);
    realm.getRunningContext().lexicalEnvironment = oldEnv;
    env = oldEnv;

    // k. If LoopContinues(result, labelSet) is false, return ? IteratorClose(iterator, UpdateEmpty(result, V)).
    if (!LoopContinues(realm, result, labelSet)) {
      (0, _invariant2.default)(result instanceof _completions.AbruptCompletion);
      result = (0, _index2.UpdateEmpty)(realm, result, V);
      (0, _invariant2.default)(result instanceof _completions.AbruptCompletion);
      throw (0, _index2.IteratorClose)(realm, iterator, result);
    }

    // l. If result.[[Value]] is not empty, let V be result.[[Value]].
    var resultValue = InternalGetResultValue(realm, result);
    if (!(resultValue instanceof _index.EmptyValue)) V = resultValue;
  }

  /* istanbul ignore next */
  (0, _invariant2.default)(false); // can't get here but there is no other way to make Flow happy
}

// ECMA262 13.7.5.11
//# sourceMappingURL=ForOfStatement.js.map