| 1 | import { AsyncMapper, AsyncPredicate, 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 | * @default true
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| 6 | */
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| 7 | objectMode?: boolean;
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| 8 | /**
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| 9 | * @default false
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| 10 | * Set true to support "multiMap" - possibility to return [] and emit 1 result for each item in the array.
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| 11 | */
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| 12 | flattenArrayOutput?: boolean;
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| 13 | /**
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| 14 | * Predicate to filter outgoing results (after mapper).
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| 15 | * Allows to not emit all results.
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| 16 | *
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| 17 | * @default to filter out undefined/null values, but pass anything else
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| 18 | *
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| 19 | * Set to `r => r` (passthrough predicate) to pass ANY value (including undefined/null)
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| 20 | */
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| 21 | predicate?: AsyncPredicate<OUT>;
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| 22 | /**
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| 23 | * Number of concurrently pending promises returned by `mapper`.
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| 24 | *
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| 25 | * @default 16 (to match default highWatermark option for objectMode streams)
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| 26 | */
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| 27 | concurrency?: number;
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| 28 | /**
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| 29 | * @default THROW_IMMEDIATELY
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| 30 | */
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| 31 | errorMode?: ErrorMode;
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| 32 | /**
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| 33 | * If defined - will be called on every error happening in the stream.
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| 34 | * Called BEFORE observable will emit error (unless skipErrors is set to true).
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| 35 | */
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| 36 | onError?: (err: Error, input: IN) => any;
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| 37 | /**
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| 38 | * Progress metric
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| 39 | *
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| 40 | * @default `stream`
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| 41 | */
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| 42 | metric?: string;
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| 43 | /**
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| 44 | * If defined - called BEFORE `final()` callback is called.
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| 45 | */
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| 46 | beforeFinal?: () => any;
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| 47 | /**
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| 48 | * If defined - called AFTER final chunk was processed.
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| 49 | */
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| 50 | afterFinal?: () => any;
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| 51 | }
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| 52 | export declare function notNullishPredicate(item: any): boolean;
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| 53 | /**
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| 54 | * Like pMap, but for streams.
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| 55 | * Inspired by `through2`.
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| 56 | * Main feature is concurrency control (implemented via `through2-concurrent`) and convenient options.
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| 57 | * Using this allows native stream .pipe() to work and use backpressure.
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| 58 | *
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| 59 | * Only works in objectMode (due to through2Concurrent).
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| 60 | *
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| 61 | * Concurrency defaults to 16.
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| 62 | *
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| 63 | * 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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| 64 | */
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| 65 | export declare function transformMap<IN = any, OUT = IN>(mapper: AsyncMapper<IN, OUT>, opt?: TransformMapOptions<IN, OUT>): TransformTyped<IN, OUT>;
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