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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at <http://mozilla.org/MPL/2.0/>. */
function hasValue(keys, store) {
let currentStore = store;
for (const key of keys) {
if (!currentStore || !currentStore.has(key)) {
return false;
}
currentStore = currentStore.get(key);
}
return true;
}
function getValue(keys, store) {
let currentStore = store;
for (const key of keys) {
if (!currentStore) {
return null;
}
currentStore = currentStore.get(key);
}
return currentStore;
}
function setValue(keys, store, value) {
const keysExceptLast = keys.slice(0, -1);
const lastKey = keys[keys.length - 1];
let currentStore = store;
for (const key of keysExceptLast) {
if (!currentStore) {
return;
}
if (!currentStore.has(key)) {
currentStore.set(key, new WeakMap());
}
currentStore = currentStore.get(key);
}
if (currentStore) {
currentStore.set(lastKey, value);
}
}
// memoize with n arguments
export default function memoize(func) {
const store = new WeakMap();
return function (...keys) {
if (hasValue(keys, store)) {
return getValue(keys, store);
}
const newValue = func.apply(null, keys);
setValue(keys, store, newValue);
return newValue;
};
}
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