import { Option } from '../data';
export type Cons<A> = {
    tag: 0;
} | {
    tag: 1;
    head: A;
    tail: Cons<A>;
};
export declare function singleton<A>(head: A): Cons<A>;
export declare function singletonFilter<A>(head: Option<A>): Cons<A>;
export declare function cons<A>(head: A, tail: Cons<A>): Cons<A>;
export declare function consFilter<A>(head: Option<A>, tail: Cons<A>): Cons<A>;
export declare function consCopyToArray<A>(xs: Cons<A>, ys: A[]): A[];
export type Concat<A> = {
    tag: 0;
} | {
    tag: 1;
    value: Cons<A>;
} | {
    tag: 2;
    lhs: Concat<A>;
    rhs: Concat<A>;
};
export declare function single<A>(value: Cons<A>): Concat<A>;
export declare function concat<A>(lhs: Concat<A>, rhs: Concat<A>): Concat<A>;
export declare function concatCopyToArray<A>(xs: Concat<A>, ys: A[]): A[];
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