-function LRUCache (options) {
- if (!(this instanceof LRUCache)) {
- return new LRUCache(options)
+class LRUCache {
+ constructor (options) {
+ if (typeof options === 'number')
+ options = { max: options }
+
+ if (!options)
+ options = {}
+
+ if (options.max && (typeof options.max !== 'number' || options.max < 0))
+ throw new TypeError('max must be a non-negative number')
+ // Kind of weird to have a default max of Infinity, but oh well.
+ const max = this[MAX] = options.max || Infinity
+
+ const lc = options.length || naiveLength
+ this[LENGTH_CALCULATOR] = (typeof lc !== 'function') ? naiveLength : lc
+ this[ALLOW_STALE] = options.stale || false
+ if (options.maxAge && typeof options.maxAge !== 'number')
+ throw new TypeError('maxAge must be a number')
+ this[MAX_AGE] = options.maxAge || 0
+ this[DISPOSE] = options.dispose
+ this[NO_DISPOSE_ON_SET] = options.noDisposeOnSet || false
+ this[UPDATE_AGE_ON_GET] = options.updateAgeOnGet || false
+ this.reset()