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88 lines
1.6 KiB
88 lines
1.6 KiB
exports.none = Object.create({
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value: function() {
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throw new Error('Called value on none');
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},
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isNone: function() {
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return true;
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},
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isSome: function() {
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return false;
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},
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map: function() {
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return exports.none;
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},
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flatMap: function() {
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return exports.none;
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},
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filter: function() {
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return exports.none;
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},
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toArray: function() {
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return [];
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},
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orElse: callOrReturn,
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valueOrElse: callOrReturn
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});
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function callOrReturn(value) {
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if (typeof(value) == "function") {
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return value();
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} else {
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return value;
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}
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}
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exports.some = function(value) {
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return new Some(value);
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};
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var Some = function(value) {
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this._value = value;
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};
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Some.prototype.value = function() {
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return this._value;
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};
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Some.prototype.isNone = function() {
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return false;
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};
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Some.prototype.isSome = function() {
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return true;
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};
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Some.prototype.map = function(func) {
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return new Some(func(this._value));
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};
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Some.prototype.flatMap = function(func) {
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return func(this._value);
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};
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Some.prototype.filter = function(predicate) {
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return predicate(this._value) ? this : exports.none;
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};
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Some.prototype.toArray = function() {
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return [this._value];
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};
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Some.prototype.orElse = function(value) {
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return this;
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};
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Some.prototype.valueOrElse = function(value) {
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return this._value;
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};
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exports.isOption = function(value) {
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return value === exports.none || value instanceof Some;
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};
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exports.fromNullable = function(value) {
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if (value == null) {
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return exports.none;
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}
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return new Some(value);
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}
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