source: trip-planner-front/node_modules/regenerator-transform/lib/meta.js

Last change on this file was 6a3a178, checked in by Ema <ema_spirova@…>, 3 years ago

initial commit

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1"use strict";
2
3var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");
4
5var _assert = _interopRequireDefault(require("assert"));
6
7var _util = require("./util.js");
8
9/**
10 * Copyright (c) 2014-present, Facebook, Inc.
11 *
12 * This source code is licensed under the MIT license found in the
13 * LICENSE file in the root directory of this source tree.
14 */
15var mMap = new WeakMap();
16
17function m(node) {
18 if (!mMap.has(node)) {
19 mMap.set(node, {});
20 }
21
22 return mMap.get(node);
23}
24
25var hasOwn = Object.prototype.hasOwnProperty;
26
27function makePredicate(propertyName, knownTypes) {
28 function onlyChildren(node) {
29 var t = (0, _util.getTypes)();
30 t.assertNode(node); // Assume no side effects until we find out otherwise.
31
32 var result = false;
33
34 function check(child) {
35 if (result) {// Do nothing.
36 } else if (Array.isArray(child)) {
37 child.some(check);
38 } else if (t.isNode(child)) {
39 _assert["default"].strictEqual(result, false);
40
41 result = predicate(child);
42 }
43
44 return result;
45 }
46
47 var keys = t.VISITOR_KEYS[node.type];
48
49 if (keys) {
50 for (var i = 0; i < keys.length; i++) {
51 var key = keys[i];
52 var child = node[key];
53 check(child);
54 }
55 }
56
57 return result;
58 }
59
60 function predicate(node) {
61 (0, _util.getTypes)().assertNode(node);
62 var meta = m(node);
63 if (hasOwn.call(meta, propertyName)) return meta[propertyName]; // Certain types are "opaque," which means they have no side
64 // effects or leaps and we don't care about their subexpressions.
65
66 if (hasOwn.call(opaqueTypes, node.type)) return meta[propertyName] = false;
67 if (hasOwn.call(knownTypes, node.type)) return meta[propertyName] = true;
68 return meta[propertyName] = onlyChildren(node);
69 }
70
71 predicate.onlyChildren = onlyChildren;
72 return predicate;
73}
74
75var opaqueTypes = {
76 FunctionExpression: true,
77 ArrowFunctionExpression: true
78}; // These types potentially have side effects regardless of what side
79// effects their subexpressions have.
80
81var sideEffectTypes = {
82 CallExpression: true,
83 // Anything could happen!
84 ForInStatement: true,
85 // Modifies the key variable.
86 UnaryExpression: true,
87 // Think delete.
88 BinaryExpression: true,
89 // Might invoke .toString() or .valueOf().
90 AssignmentExpression: true,
91 // Side-effecting by definition.
92 UpdateExpression: true,
93 // Updates are essentially assignments.
94 NewExpression: true // Similar to CallExpression.
95
96}; // These types are the direct cause of all leaps in control flow.
97
98var leapTypes = {
99 YieldExpression: true,
100 BreakStatement: true,
101 ContinueStatement: true,
102 ReturnStatement: true,
103 ThrowStatement: true
104}; // All leap types are also side effect types.
105
106for (var type in leapTypes) {
107 if (hasOwn.call(leapTypes, type)) {
108 sideEffectTypes[type] = leapTypes[type];
109 }
110}
111
112exports.hasSideEffects = makePredicate("hasSideEffects", sideEffectTypes);
113exports.containsLeap = makePredicate("containsLeap", leapTypes);
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