113 lines
2.4 KiB
JavaScript
113 lines
2.4 KiB
JavaScript
var hasOwnProperty = Object.prototype.hasOwnProperty
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module.exports = PseudoMap
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function PseudoMap (set) {
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if (!(this instanceof PseudoMap)) // whyyyyyyy
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throw new TypeError("Constructor PseudoMap requires 'new'")
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this.clear()
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if (set) {
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if ((set instanceof PseudoMap) ||
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(typeof Map === 'function' && set instanceof Map))
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set.forEach(function (value, key) {
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this.set(key, value)
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}, this)
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else if (Array.isArray(set))
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set.forEach(function (kv) {
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this.set(kv[0], kv[1])
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}, this)
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else
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throw new TypeError('invalid argument')
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}
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}
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PseudoMap.prototype.forEach = function (fn, thisp) {
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thisp = thisp || this
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Object.keys(this._data).forEach(function (k) {
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if (k !== 'size')
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fn.call(thisp, this._data[k].value, this._data[k].key)
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}, this)
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}
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PseudoMap.prototype.has = function (k) {
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return !!find(this._data, k)
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}
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PseudoMap.prototype.get = function (k) {
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var res = find(this._data, k)
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return res && res.value
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}
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PseudoMap.prototype.set = function (k, v) {
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set(this._data, k, v)
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}
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PseudoMap.prototype.delete = function (k) {
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var res = find(this._data, k)
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if (res) {
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delete this._data[res._index]
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this._data.size--
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}
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}
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PseudoMap.prototype.clear = function () {
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var data = Object.create(null)
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data.size = 0
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Object.defineProperty(this, '_data', {
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value: data,
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enumerable: false,
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configurable: true,
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writable: false
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})
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}
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Object.defineProperty(PseudoMap.prototype, 'size', {
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get: function () {
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return this._data.size
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},
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set: function (n) {},
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enumerable: true,
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configurable: true
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})
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PseudoMap.prototype.values =
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PseudoMap.prototype.keys =
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PseudoMap.prototype.entries = function () {
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throw new Error('iterators are not implemented in this version')
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}
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// Either identical, or both NaN
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function same (a, b) {
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return a === b || a !== a && b !== b
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}
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function Entry (k, v, i) {
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this.key = k
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this.value = v
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this._index = i
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}
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function find (data, k) {
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for (var i = 0, s = '_' + k, key = s;
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hasOwnProperty.call(data, key);
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key = s + i++) {
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if (same(data[key].key, k))
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return data[key]
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}
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}
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function set (data, k, v) {
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for (var i = 0, s = '_' + k, key = s;
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hasOwnProperty.call(data, key);
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key = s + i++) {
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if (same(data[key].key, k)) {
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data[key].value = v
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return
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}
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}
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data.size++
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data[key] = new Entry(k, v, key)
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}
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