16 lines
735 B
TypeScript
16 lines
735 B
TypeScript
//// [subtypeRelationForNever.ts]
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function fail(message: string) : never { throw new Error(message); }
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function withFew<a, r>(values: a[], haveFew: (values: a[]) => r, haveNone: (reason: string) => r): r {
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return values.length > 0 ? haveFew(values) : haveNone('No values.');
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}
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function id<a>(value: a) : a { return value; }
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const result = withFew([1, 2, 3], id, fail); // expected result is number[]
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//// [subtypeRelationForNever.js]
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function fail(message) { throw new Error(message); }
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function withFew(values, haveFew, haveNone) {
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return values.length > 0 ? haveFew(values) : haveNone('No values.');
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}
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function id(value) { return value; }
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var result = withFew([1, 2, 3], id, fail); // expected result is number[]
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