如何获得箭头函数的主体作为字符串? [英] How to get an arrow function's body as a string?
问题描述
如何以箭头函数{}
之间的字符串形式获取代码?
How to get code as string between {}
of arrow function ?
var myFn=(arg1,..,argN)=>{
/**
*Want to parse
* ONLY which is between { and }
* of arrow function
*/
};
如果很容易解析简单函数的正文:myFn.toString().match(/function[^{]+\{([\s\S]*)\}$/)[1];
就足够了.但是,Arrow函数的定义中不包含function
关键字.
If it is easy to parse body of simple function : myFn.toString().match(/function[^{]+\{([\s\S]*)\}$/)[1];
is enough . However, Arrow function does not contains function
keyword in its definition .
推荐答案
这是我的尝试:
function getArrowFunctionBody(f) {
const matches = f.toString().match(/^(?:\s*\(?(?:\s*\w*\s*,?\s*)*\)?\s*?=>\s*){?([\s\S]*)}?$/);
if (!matches) {
return null;
}
const firstPass = matches[1];
// Needed because the RegExp doesn't handle the last '}'.
const secondPass =
(firstPass.match(/{/g) || []).length === (firstPass.match(/}/g) || []).length - 1 ?
firstPass.slice(0, firstPass.lastIndexOf('}')) :
firstPass
return secondPass;
}
const K = (x) => (y) => x;
const I = (x) => (x);
const V = (x) => (y) => (z) => z(x)(y);
const f = (a, b) => {
const c = a + b;
return c;
};
const empty = () => { return undefined; };
console.log(getArrowFunctionBody(K));
console.log(getArrowFunctionBody(I));
console.log(getArrowFunctionBody(V));
console.log(getArrowFunctionBody(f));
console.log(getArrowFunctionBody(empty));
它可能比需要的更为冗长,因为我尝试对空白留出大手笔.另外,如果有人知道如何跳过第二遍,我将非常高兴.最终,我决定不进行任何修剪,将其留给调用方.
It's probably more verbose than it needs to be because I tried to be generous about white space. Also, I'd be glad to hear if anyone knows how to skip the second pass. Finally, I decided not to do any trimming, leaving that to the caller.
当前仅处理简单的函数参数.您还需要一个本机支持箭头功能的浏览器.
Currently only handles simple function parameters. You'll also need a browser that natively supports arrow functions.
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