import { Either } from './utils';
export declare class ValidationErrors extends Error {
    readonly errors: string[];
    constructor(errors: string[]);
}
export declare type DirtyEnvConfig<C> = Partial<Record<keyof C, string>>;
declare type ValidatorFunction<T> = (value: string) => Either<string, T>;
export declare type Validator<T> = {
    default?: T;
    validate: ValidatorFunction<T>;
};
export declare const validator: <T>(validator: Validator<T>) => Validator<T>;
export declare type Validators<C> = {
    [P in keyof C]: Validator<C[P]>;
};
export declare const validated: <C, R>(validators: Validators<C>, parse: (env: C) => R) => (dirtyEnv: Partial<Record<keyof C, string>>) => ValidationErrors | R;
export declare const noValidation: () => ValidatorFunction<string>;
export declare const validateListOfValues: <T extends string>(allowedValues: readonly T[]) => ValidatorFunction<T>;
export declare const validateRegExp: <T extends string>(regex: RegExp) => ValidatorFunction<T>;
export declare const validateYesNo: () => ValidatorFunction<boolean>;
export declare const validateNumber: (min: number, max: number) => ValidatorFunction<number>;
export declare const validateFileReadable: () => ValidatorFunction<string>;
export {};