27 lines
1.1 KiB
TypeScript
27 lines
1.1 KiB
TypeScript
//// [promiseChaining1.ts]
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// same example but with constraints on each type parameter
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class Chain2<T extends { length: number }> {
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constructor(public value: T) { }
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then<S extends Function>(cb: (x: T) => S): Chain2<S> {
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var result = cb(this.value);
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// should get a fresh type parameter which each then call
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var z = this.then(x => result)/*S*/.then(x => "abc")/*Function*/.then(x => x.length)/*number*/; // Should error on "abc" because it is not a Function
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return new Chain2(result);
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}
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}
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//// [promiseChaining1.js]
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// same example but with constraints on each type parameter
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var Chain2 = (function () {
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function Chain2(value) {
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this.value = value;
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}
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Chain2.prototype.then = function (cb) {
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var result = cb(this.value);
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// should get a fresh type parameter which each then call
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var z = this.then(function (x) { return result; }) /*S*/.then(function (x) { return "abc"; }) /*Function*/.then(function (x) { return x.length; }); // Should error on "abc" because it is not a Function
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return new Chain2(result);
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};
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return Chain2;
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})();
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