| 1 | import { AbortableAsyncMapper, AsyncPredicate, CommonLogger, ErrorMode } from '@naturalcycles/js-lib';
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| 2 | import { TransformTyped } from '../stream.model';
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| 3 | export interface TransformMapOptions<IN = any, OUT = IN> {
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| 4 | /**
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| 5 | * Set true to support "multiMap" - possibility to return [] and emit 1 result for each item in the array.
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| 6 | *
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| 7 | * @default false
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| 8 | */
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| 9 | flattenArrayOutput?: boolean;
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| 10 | /**
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| 11 | * Predicate to filter outgoing results (after mapper).
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| 12 | * Allows to not emit all results.
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| 13 | *
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| 14 | * Defaults to "pass everything" (including null, undefined, etc).
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| 15 | * Simpler way to exclude certain cases is to return SKIP symbol from the mapper.
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| 16 | */
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| 17 | predicate?: AsyncPredicate<OUT>;
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| 18 | /**
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| 19 | * Number of concurrently pending promises returned by `mapper`.
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| 20 | *
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| 21 | * @default 16 (to match default highWatermark option for objectMode streams)
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| 22 | */
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| 23 | concurrency?: number;
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| 24 | /**
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| 25 | * @default THROW_IMMEDIATELY
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| 26 | */
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| 27 | errorMode?: ErrorMode;
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| 28 | /**
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| 29 | * If defined - will be called on every error happening in the stream.
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| 30 | * Called BEFORE observable will emit error (unless skipErrors is set to true).
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| 31 | */
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| 32 | onError?: (err: unknown, input: IN) => any;
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| 33 | /**
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| 34 | * Progress metric
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| 35 | *
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| 36 | * @default `stream`
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| 37 | */
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| 38 | metric?: string;
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| 39 | logger?: CommonLogger;
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| 40 | }
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| 41 | /**
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| 42 | * Like pMap, but for streams.
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| 43 | * Inspired by `through2`.
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| 44 | * Main feature is concurrency control (implemented via `through2-concurrent`) and convenient options.
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| 45 | * Using this allows native stream .pipe() to work and use backpressure.
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| 46 | *
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| 47 | * Only works in objectMode (due to through2Concurrent).
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| 48 | *
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| 49 | * Concurrency defaults to 16.
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| 50 | *
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| 51 | * If an Array is returned by `mapper` - it will be flattened and multiple results will be emitted from it. Tested by Array.isArray().
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| 52 | */
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| 53 | export declare function transformMap<IN = any, OUT = IN>(mapper: AbortableAsyncMapper<IN, OUT>, opt?: TransformMapOptions<IN, OUT>): TransformTyped<IN, OUT>;
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