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