import type { DataStream, DataType } from '../data-module/types';
import type { DurationViewport, HistoricalViewport, Viewport } from '../data-module/data-cache/requestTypes';
/**
 * Predicate Utilities
 *
 * A place for generic predicates. Useful when needing predicates which play nicely
 * with typescript, or other non-trivial predicate logic.
 *
 * Providing smart predicates with built in type guards can give us stronger typing in our business logic.
 * https://www.typescriptlang.org/docs/handbook/advanced-types.html#type-guards-and-differentiating-types
 *
 * Example:
 *
 * Without Type Guards (to be avoided):
 * ```
 * const maybeItems : (Item | null)[] = SOME_MAYBE_ITEMS;
 * const items: Item[] = maybeItems.filter(x => x != null) as Item[];
 * ```
 *
 * With Type Guards:
 * ```
 * const maybeItems : (Item | null)[] = SOME_MAYBE_ITEMS;
 * const items: Item[] = maybeItems.filter(isDefined);
 * ```
 *
 * No type casting necessary :-) all you have to do is trust that the shared predicate properly
 * type guards.
 *
 */
export declare const isDefined: <T>(value: T | null | undefined) => value is T;
export declare const isValid: <T>(predicate: (t: Partial<T>) => boolean) => (t: Partial<T>) => t is T;
export declare const isSupportedDataType: (supportsString: boolean) => ({ dataType }: {
    dataType: DataType;
}) => boolean;
export declare const isNumberDataStream: (stream: DataStream) => stream is DataStream<number>;
export declare const isNumber: <T>(val: T | number) => val is number;
export declare const isHistoricalViewport: (viewport: Viewport) => viewport is HistoricalViewport;
export declare const isDurationViewport: (viewport: Viewport) => viewport is DurationViewport;
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