"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.MemoLazy = void 0;
class MemoLazy {
constructor(selector, creator) {
this.selector = selector;
this.creator = creator;
this.selected = undefined;
this._value = undefined;
}
get hasValue() {
return this._value !== undefined;
}
get value() {
const selected = this.selector();
if (this._value !== undefined && equals(this.selected, selected)) {
// value exists and selected hasn't changed, so return the cached value
return this._value;
}
this.selected = selected;
const result = this.creator(selected);
this.value = result;
return result;
}
set value(value) {
this._value = value;
}
}
exports.MemoLazy = MemoLazy;
function equals(firstValue, secondValue) {
const isFirstObject = typeof firstValue === "object" && firstValue !== null;
const isSecondObject = typeof secondValue === "object" && secondValue !== null;
// do a shallow comparison of objects, arrays etc.
if (isFirstObject && isSecondObject) {
const keys1 = Object.keys(firstValue);
const keys2 = Object.keys(secondValue);
return keys1.length === keys2.length && keys1.every((key) => equals(firstValue[key], secondValue[key]));
}
// otherwise just compare the values directly
return firstValue === secondValue;
}
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