import { type MapFunction } from '../value/map';
import { type Maybe } from '../value/maybe.type';
/**
 * Trims leading and trailing whitespace from a string.
 *
 * @param input The string to trim.
 * @returns The trimmed string.
 */
export declare function stringTrimFunction(input: string): string;
/**
 * Converts a string to uppercase.
 *
 * @param input The string to convert.
 * @returns The uppercase string.
 */
export declare function stringToUppercaseFunction(input: string): string;
/**
 * Converts a string to lowercase.
 *
 * @param input The string to convert.
 * @returns The lowercase string.
 */
export declare function stringToLowercaseFunction(input: string): string;
/**
 * Configuration for transforming a string.
 * Defines operations like trimming, case conversion, or applying a custom transform function.
 *
 * @template S The specific string type, defaults to `string`.
 */
export type TransformStringFunctionConfig<S extends string = string> = {
    /**
     * If true, the string will be trimmed of leading/trailing whitespace.
     * Trimming occurs before other transformations like case conversion or a custom `transform` function.
     */
    readonly trim?: boolean;
    /**
     * If true, the string will be converted to lowercase.
     * This is ignored if a custom `transform` function is provided.
     */
    readonly toLowercase?: boolean;
    /**
     * If true, the string will be converted to uppercase.
     * This is ignored if a custom `transform` function is provided and takes precedence over `toLowercase` if both are true.
     */
    readonly toUppercase?: boolean;
    /**
     * Slices the string based on the configuration.
     */
    readonly slice?: SliceStringFunctionConfig;
    /**
     * An optional custom function to transform the string.
     * If provided, `toLowercase` and `toUppercase` are ignored. Trimming (if `trim` is true) occurs before this custom transform.
     */
    readonly transform?: TransformStringFunction<S>;
};
/**
 * A reference object holding a `TransformStringFunctionConfig`.
 *
 * @template S The specific string type, defaults to `string`.
 */
export interface TransformStringFunctionConfigRef<S extends string = string> {
    /**
     * The string transformation configuration.
     */
    readonly transform: TransformStringFunctionConfig<S>;
}
/**
 * A function that maps a string of type S to another string of type S.
 *
 * @template S The specific string type, defaults to `string`.
 */
export type TransformStringFunction<S extends string = string> = MapFunction<S, S>;
/**
 * Input type for string transformation configuration.
 * Can be a full `TransformStringFunctionConfig` object or a direct `TransformStringFunction`.
 *
 * @template S The specific string type, defaults to `string`.
 */
export type TransformStringFunctionConfigInput<S extends string = string> = TransformStringFunctionConfig<S> | TransformStringFunction<S>;
/**
 * Normalizes a `TransformStringFunctionConfigInput` into a `TransformStringFunctionConfig` object.
 * If the input is a function, it's wrapped into a config object with that function as the `transform` property.
 * If the input is undefined, it returns undefined.
 *
 * @template S The specific string type, defaults to `string`.
 * @param config The configuration input to normalize.
 * @returns A `TransformStringFunctionConfig` object, or `undefined` if the input config is undefined.
 */
export declare function transformStringFunctionConfig<S extends string = string>(config?: TransformStringFunctionConfigInput<S>): Maybe<TransformStringFunctionConfig<S>>;
/**
 * Creates a string transformation function based on the provided configuration.
 * The resulting function will apply transformations in a specific order:
 * 1. Trimming (if `config.trim` is true).
 * 2. Slicing (if `config.slice` is provided).
 * 2. Custom `config.transform` function (if provided).
 * 3. Uppercase conversion (if `config.toUppercase` is true and no `config.transform`).
 * 4. Lowercase conversion (if `config.toLowercase` is true and no `config.transform` or `config.toUppercase`).
 * If no transformations are specified, the identity function is returned.
 *
 * @template S The specific string type, defaults to `string`.
 * @param config The `TransformStringFunctionConfig` detailing the transformations.
 * @returns A `TransformStringFunction` that applies the configured transformations.
 */
export declare function transformStringFunction<S extends string = string>(config: TransformStringFunctionConfig<S>): TransformStringFunction<S>;
/**
 * Adds a prefix to the input string if it does not already start with that prefix.
 *
 * @param prefix - The prefix to add.
 * @param input - The string to modify.
 * @returns The string with the prefix applied.
 */
export declare function addPrefix(prefix: string, input: string): string;
/**
 * Function that adds a configured prefix to the input string if it does not exist on that string.
 */
export type AddPrefixFunction = (input: string) => string;
/**
 * Creates a function that adds a configured prefix to the input string if it does not exist on that string.
 *
 * @param prefix The prefix to add.
 * @returns A function that adds the prefix to a string.
 */
export declare function addPrefixFunction(prefix: string): AddPrefixFunction;
/**
 * Function that adds a configured suffix to the input string if it does not exist on that string.
 */
export type AddSuffixFunction = TransformStringFunction;
/**
 * Adds a suffix to a string if it does not already end with that suffix.
 *
 * @param suffix The suffix to add.
 * @param input The string to modify.
 * @returns The modified string.
 */
export declare function addSuffix(suffix: string, input: string): string;
/**
 * Creates a function that adds a configured suffix to the input string if it does not exist on that string.
 *
 * @param suffix The suffix to add.
 * @returns A function that adds the suffix to a string.
 */
export declare function addSuffixFunction(suffix: string): AddSuffixFunction;
/**
 * Function that pads the start of a string to a minimum length.
 */
export type PadStartFunction = TransformStringFunction;
/**
 * Pads the start of a string to a minimum length.
 *
 * @param minLength The minimum length of the string.
 * @param padCharacter The character to use for padding.
 * @returns A function that pads the start of a string.
 */
export declare function padStartFunction(minLength: number, padCharacter: string): PadStartFunction;
/**
 * Function that slices and concats parts of a string based on the configuration.
 */
export type SliceStringFunction = TransformStringFunction;
/**
 * Configuration for sliceStringFunction()
 */
export interface SliceStringFunctionConfig {
    /**
     * The number of characters to take from the start of the string.
     *
     * When both fromStart and fromEnd are specified, the first N characters are concatenated with the last M characters.
     * If the total (fromStart + fromEnd) is greater than or equal to the string length, the entire string is returned.
     *
     * If undefined or 0, only takes from the end of the string. The absolute value of this number is used.
     */
    readonly fromStart?: number;
    /**
     * The number of characters to take from the end of the string.
     *
     * When both fromStart and fromEnd are specified, the first N characters are concatenated with the last M characters.
     * If the total (fromStart + fromEnd) is greater than or equal to the string length, the entire string is returned.
     *
     * If undefined or 0, only takes from the start of the string. The absolute value of this number is used.
     */
    readonly fromEnd?: number;
}
/**
 * Creates a function that slices and concats parts of a string based on the configuration.
 *
 * @param config The configuration for the slice function.
 * @returns A SliceStringFunction.
 */
export declare function sliceStringFunction(config: SliceStringFunctionConfig): SliceStringFunction;