prepack/lib/evaluators/CatchClause.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 = function (ast, strictCode, env, realm, thrownValue) {
  (0, _invariant2.default)(thrownValue instanceof _completions.ThrowCompletion, "Metadata isn't a throw completion");

  // 1. Let oldEnv be the running execution context's LexicalEnvironment.
  let oldEnv = realm.getRunningContext().lexicalEnvironment;

  // 2. Let catchEnv be NewDeclarativeEnvironment(oldEnv).
  let catchEnv = _singletons.Environment.NewDeclarativeEnvironment(realm, oldEnv);

  // 3. Let catchEnvRec be catchEnv's EnvironmentRecord.
  let catchEnvRec = catchEnv.environmentRecord;

  // 4. For each element argName of the BoundNames of CatchParameter, do
  for (let argName of _singletons.Environment.BoundNames(realm, ast.param)) {
    // a. Perform ! catchEnvRec.CreateMutableBinding(argName, false).
    catchEnvRec.CreateMutableBinding(argName, false);
  }

  // 5. Set the running execution context's LexicalEnvironment to catchEnv.
  realm.getRunningContext().lexicalEnvironment = catchEnv;

  try {
    // 6. Let status be the result of performing BindingInitialization for CatchParameter passing thrownValue and catchEnv as arguments.
    _singletons.Environment.BindingInitialization(realm, ast.param, thrownValue.value, strictCode, catchEnv);

    // 7. If status is an abrupt completion, then
    // a. Set the running execution context's LexicalEnvironment to oldEnv.
    // b. Return Completion(status).

    // 8. Let B be the result of evaluating Block.
    let B = catchEnv.evaluate(ast.body, strictCode);
    (0, _invariant2.default)(B instanceof _index.Value);

    // 10. Return Completion(B).
    return B;
  } finally {
    // 9. Set the running execution context's LexicalEnvironment to oldEnv.
    realm.getRunningContext().lexicalEnvironment = oldEnv;
    realm.onDestroyScope(catchEnv);
  }
};

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

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

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

var _invariant2 = _interopRequireDefault(_invariant);

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

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