/**
 * A lazy `thunk`
 */
export declare type Lazy<A> = () => A;
/**
 * Creates a lazy function.
 */
export declare const lazy: <A>(a: A) => Lazy<A>;
/**
 * A no-operation funciton.
 */
export declare const noop: () => void;
/**
  * Identity
  */
export declare const identity: <A>(a: A) => A;
/**
  * A thunk returns self.
  */
export declare const constant: <A>(a: A) => Lazy<A>;
/**
  * A thunk returns always `true`.
  */
export declare const constTrue: Lazy<boolean>;
/**
  * A thunk returns always `false`.
  */
export declare const constFalse: Lazy<boolean>;
/**
  * A thunk returns always `null`.
  */
export declare const constNull: Lazy<null>;
/**
  * A thunk returns always `undefined`.
  */
export declare const constUndefined: Lazy<undefined>;
/**
  * A thunk returns always `void`.
  */
export declare const constVoid: Lazy<undefined>;
/**
 * Returns whether the value is null or undefined.
 */
export declare const isNullable: (a: unknown) => a is null | undefined;
/**
 * Returns whether the value is `NonNullable`.
 */
export declare const isNonNullable: <A>(a: A) => a is NonNullable<A>;