ts-toolbelt
Version:
TypeScript's largest utility library
50 lines (49 loc) • 1.58 kB
TypeScript
import { IterationOf } from '../Iteration/IterationOf';
import { Iteration } from '../Iteration/Iteration';
import { Pos } from '../Iteration/Pos';
import { Prepend } from './Prepend';
import { Way } from '../Iteration/_Internal';
import { List } from './List';
import { Prev } from '../Iteration/Prev';
import { Cast } from '../Any/Cast';
import { Tail } from './Tail';
import { Extends } from '../Any/Extends';
/**
* starts in reverse from `N` till `N` = 0
* @hidden
*/
declare type TakeForth<L extends List, N extends Iteration, I extends Iteration = Prev<N>, LN extends List = []> = {
0: TakeForth<L, N, Prev<I>, Prepend<LN, L[Pos<I>]>>;
1: LN;
}[Extends<-1, Pos<I>>];
/**
* starts in reverse from the end till `N` = 0
* @hidden
*/
declare type TakeBack<L extends List, N extends Iteration> = {
0: TakeBack<Tail<L>, Prev<N>>;
1: L;
}[Extends<0, Pos<N>>];
/**
* @hidden
*/
declare type __Take<L extends List, N extends Iteration, way extends Way> = {
'->': TakeForth<L, N>;
'<-': TakeBack<L, N>;
}[way];
/**
* @hidden
*/
export declare type _Take<L extends List, N extends number, way extends Way = '->'> = __Take<L, IterationOf<N>, way> extends infer X ? Cast<X, List> : never;
/**
* Extract `N` entries out of `L`
* @param L to extract from
* @param N to extract out
* @param way (?=`'->'`) to extract from end
* @returns [[List]]
* @example
* ```ts
* ```
*/
export declare type Take<L extends List, N extends number, way extends Way = '->'> = L extends unknown ? N extends unknown ? _Take<L, N, way> : never : never;
export {};