11 lines
591 B
JavaScript
11 lines
591 B
JavaScript
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import { EmptyError } from '../util/EmptyError';
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import { filter } from './filter';
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import { take } from './take';
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import { defaultIfEmpty } from './defaultIfEmpty';
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import { throwIfEmpty } from './throwIfEmpty';
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import { identity } from '../util/identity';
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export function first(predicate, defaultValue) {
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const hasDefaultValue = arguments.length >= 2;
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return (source) => source.pipe(predicate ? filter((v, i) => predicate(v, i, source)) : identity, take(1), hasDefaultValue ? defaultIfEmpty(defaultValue) : throwIfEmpty(() => new EmptyError()));
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}
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//# sourceMappingURL=first.js.map
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