22 lines
292 B
JavaScript
22 lines
292 B
JavaScript
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// @noflow
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// refinement of disjoint unions
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type Empty = { }
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type Success = {
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type: 'SUCCESS';
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result: string;
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};
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type Error = {
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type: 'ERROR';
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} & Empty;
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export type T = Success | Error;
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function foo(x: T) {
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if (x.type === 'SUCCESS') return x.result;
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else return x.result;
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}
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