eval5
Version:
A JavaScript interpreter written in JavaScript
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Markdown
中文 | [English](./README-en_US.md)
[](https://github.com/bplok20010/eval5/blob/master/LICENSE)
[](https://www.npmjs.com/package/eval5)
[](https://raw.githubusercontent.com/bplok20010/eval5/master/umd/eval5.min.js)
基于 TypeScript 编写的 JavaScript 解释器，支持完整 ES5 语法
**支持浏览器、node.js、小程序等 JavaScript 运行环境**
[在线体验](https://bplok20010.github.io/eval5/)
[更多示例](https://bplok20010.github.io/eval5/examples.html)
- 浏览器环境中需要使用沙盒环境执行 JavaScript 脚本
- 控制执行时长
- 不支持`eval` `Function`的 JavaScript 运行环境：如 微信小程序 [demo](https://github.com/bplok20010/eval5-wx-demo) [we-script](https://github.com/bplok20010/we-script) [taro-script](https://github.com/bplok20010/taro-script)
- 研究/学习用
ES5
```
npm install --save eval5
```
[](https://codesandbox.io/s/eval5-zxndl?fontsize=14&hidenavigation=1&theme=dark)
```javascript
import { Interpreter } from "eval5";
const interpreter = new Interpreter(window, {
timeout: 1000,
});
let result;
try {
result = interpreter.evaluate("1+1");
console.log(result);
interpreter.evaluate("var a=100");
interpreter.evaluate("var b=200");
result = interpreter.evaluate("a+b");
console.log(result);
} catch (e) {
console.log(e);
}
```
```ts
interface Options {
// 默认为：0，不限制
timeout?: number;
// 根作用域，只读
rootContext?: {} | null;
globalContextInFunction?: any;
}
```
示例
```
import { Interpreter } from "eval5";
const ctx = {};
const interpreter = new Interpreter(ctx, {
rootContext: window,
timeout: 1000,
});
interpreter.evaluate(`
a = 100;
console.log(a); // 100
`);
window.a;//undefined
```
**`version`**
当前版本
**`global`**
默认值: `{}`
设置默认的全局作用域
```js
Interpreter.global = window;
const interpreter = new Interpreter();
interpreter.evaluate('alert("hello eval5")');
```
**`globalContextInFunction`**
默认值: `undefined`
`eval5` 不支持 `use strict` 严格模式, 在非严格下的函数中`this`默认指向的是全局作用域，但在`eval5`中是`undefined`， 可通过`globalContextInFunction`来设置默认指向。
```js
import { Interpreter } from "Interpreter";
const ctx = {};
const interpreter = new Interpreter(ctx);
interpreter.evaluate(`
this; // ctx
function func(){
return this; // undefined
}
func();
`);
```
```js
import { Interpreter } from "Interpreter";
Interpreter.globalContextInFunction = window;
const ctx = {};
const interpreter = new Interpreter({});
interpreter.evaluate(`
this; // ctx
function func(){
return this; // window
}
func();
`);
```
原因，示例代码：
> **注意: alert异常**
```
import { Interpreter } from "Interpreter";
Interpreter.globalContextInFunction = {};
const ctx = {alert: alert};
const interpreter = new Interpreter(ctx);
interpreter.evaluate(`
// throw Illegal invocation
alert('Hello eval5'); // 同 alert.call({}, 'Hello eval5')
`);
```
**`constructor(context = Interpreter.global, options?: Options )`**
构造函数
**`evaluate(code: string): any`**
执行给定的字符串代码，并返回最后一个表达式的值
```js
import { Interpreter } from "Interpreter";
const interpreter = new Interpreter(window);
const result = interpreter.evaluate(`
var a = 100;
var b = 200;
a+b;
`);
console.log(result); // 300
```
**`appendCode(code: string): any`**
`evaluate`的别名
**`getExecutionTime(): number`**
获取上一次调用`evaluate`的执行时长
**`setExecTimeout(timeout: number = 0): void`**
设置执行时长
**`getOptions(): Readonly<Options>`**
获取解释器参数
---
执行给定的字符串代码，并返回最后一个表达式的值
> 注: 该函数每次执行都会创建一个新的解释器
```js
import { evaluate } from "eval5";
evaluate(
`
var a = 100;
var b = 100;
console.log(a+b);
`,
{ console: console }
); // 200
evaluate(`
a;
`); // a is not defined
```
该函数会将`Interpreter.global` `Interpreter.globalContextInFunction`当作默认值并创建新的解释器
```js
import { Function } from "eval5";
const func = new Function("a", "b", "return a+b;");
console.log(func(100, 200)); // 300
```
查看 [vm](https://nodejs.org/dist/latest-v13.x/docs/api/vm.html)
- vm.createContext
- vm.compileFunction
- vm.runInContext
- vm.runInNewContext
- vm.Script
MIT
- [evaljs](https://github.com/marten-de-vries/evaljs)
- [closure-interpreter](https://github.com/int3/closure-interpreter)