babel-core/lib/babel/transformation/transformers/es7/comprehensions.js

Turn ES6 code into readable vanilla ES5 with source maps

"use strict";

var _interopRequireWildcard = function (obj) { return obj && obj.__esModule ? obj : { "default": obj }; };

var _interopRequire = function (obj) { return obj && obj.__esModule ? obj["default"] : obj; };

exports.ComprehensionExpression = ComprehensionExpression;
exports.__esModule = true;

var buildComprehension = _interopRequire(require("../../helpers/build-comprehension"));

var traverse = _interopRequire(require("../../../traversal"));

var util = _interopRequireWildcard(require("../../../util"));

var t = _interopRequireWildcard(require("../../../types"));

var metadata = {
  stage: 0
};

exports.metadata = metadata;

function ComprehensionExpression(node, parent, scope, file) {
  var callback = array;
  if (node.generator) callback = generator;
  return callback(node, parent, scope, file);
}

function generator(node) {
  var body = [];
  var container = t.functionExpression(null, [], t.blockStatement(body), true);
  container.shadow = true;

  body.push(buildComprehension(node, function () {
    return t.expressionStatement(t.yieldExpression(node.body));
  }));

  return t.callExpression(container, []);
}

function array(node, parent, scope, file) {
  var uid = scope.generateUidBasedOnNode(parent);

  var container = util.template("array-comprehension-container", {
    KEY: uid
  });
  container.callee.shadow = true;

  var block = container.callee.body;
  var body = block.body;

  if (traverse.hasType(node, scope, "YieldExpression", t.FUNCTION_TYPES)) {
    container.callee.generator = true;
    container = t.yieldExpression(container, true);
  }

  var returnStatement = body.pop();

  body.push(buildComprehension(node, function () {
    return util.template("array-push", {
      STATEMENT: node.body,
      KEY: uid
    }, true);
  }));
  body.push(returnStatement);

  return container;
}