I'm working with decorator functions and i do not want to use bind for passing this value here, instead I wanna use a wrapper function and execute the code in there.
But i faced with this error ->
Uncaught RangeError: Maximum call stack size exceeded
And here is the code:
let math = {
multi(n, type) {
if(type == 'double') {
this.printSomething(n * 2);
}
else if (type == 'triple') {
this.printSomething(n * 3);
}
},
printSomething(result) {
console.log(result);
}
};
function cachingDecorator(func) {
let cache = new Map();
return function(n, type) {
if(cache.has(n))
return cache.get(n);
let result = func(n, type);
cache.set(n, result);
return result;
};
};
math.multi = cachingDecorator((n, type) => math.multi(n, type));
math.multi(10, 'double');
I used Chrome Developer Tools though, but I could not fix the problem.
I know that this error ocurred because there is a recursion. But where?
The problem is that you're reassigning math.multi to the caching version, then the caching version of it uses the reassigned value here:
math.multi = cachingDecorator((n, type) => math.multi(n, type));
// −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−^^^^^^^^^^
Instead, you need to remember and use the original:
const originalMulti = math.multi;
math.multi = cachingDecorator((n, type) => originalMulti.call(math, n, type));
// −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−^^^^^^^^^^^^^^^^^^^^^^^
Note that I had to use .call(math to ensure this is correct, since I copied math.multi to a variable; calling it directly later doesn't set this correctly.
Live Example:
let math = {
multi(n, type) {
if(type == 'double') {
this.printSomething(n * 2);
}
else if (type == 'triple') {
this.printSomething(n * 3);
}
},
printSomething(result) {
console.log(result);
}
};
function cachingDecorator(func) {
let cache = new Map();
return function(n, type) {
if(cache.has(n))
return cache.get(n);
let result = func(n, type);
cache.set(n, result);
return result;
};
}
const originalMulti = math.multi;
math.multi = cachingDecorator((n, type) => originalMulti.call(math, n, type));
math.multi(10, 'double');