import type { Num, U } from './index.mjs';
/**
 * Returns the length of the given string S.
 * @example
 * ```ts
 * Length<'abc'> => 3
 * ```
 */
export type Length<S extends string> = LengthHelper<S, 0>;
type LengthHelper<S extends string, Result extends number> = S extends '' ? Result : S extends `${string}${string}${string}${string}${string}${string}${string}${string}${string}${string}${infer Rest}` ? LengthHelper<Rest, Num.Add<Result, 10>> : S extends `${string}${string}${string}${string}${string}${infer Rest}` ? LengthHelper<Rest, Num.Add<Result, 5>> : S extends `${string}${infer Rest}` ? LengthHelper<Rest, Num.Add<Result, 1>> : Result;
/**
 * Convenience type to represent the concatenation of two string types.
 * @example
 * ```ts
 * Append<'abc', 'def'> => 'abcdef'
 * Append<'abc', 'd' | 'e'> => 'abcd' | 'abce'
 * ```
 */
export type Append<Start extends string, End extends string> = `${Start}${End}`;
/**
 * Convenience type to represent the concatenation of three string types.
 * @example
 * ```ts
 * AppendTwo<'abc', 'def', 'ghi'> => 'abcdefghi'
 * AppendTwo<'abc', 'd' | 'e', 'fgh'> => 'abcdfgh' | 'abcefgh'
 * ```
 */
export type AppendTwo<Start extends string, Middle extends string, End extends string> = `${Start}${Middle}${End}`;
/**
 * Returns false if the given string is empty, true otherwise.
 * @example
 * ```ts
 * IsNonEmptyString<''> => false
 * IsNonEmptyString<'abc'> => true
 * ```
 */
export type IsNonEmptyString<S extends string> = '' extends S ? false : true;
/**
 * Returns never if the given string is empty, otherwise the given string.
 * @example
 * ```ts
 * NonEmptyString<''> => never
 * NonEmptyString<'abc'> => 'abc'
 * ```
 */
export type NonEmptyString<S extends string> = '' extends S ? never : unknown;
/**
 * If the given string does not start with the given `Start` type, returns false.
 * Otherwise, returns a tuple containing the matched start and the rest.
 * @example
 * ```ts
 * StartsWith<'abcd', 'ab'> => ['ab', 'cd']
 * StartsWith<'abcd', 'd'> => false
 * StartsWith<'abcd', 'ab' | 'bc'> => ['ab', 'cd']
 * StartsWith<'abcd', 'ab' | 'a'> => ['ab', 'cd'] | ['a', 'bcd']
 * ```
 */
export type StartsWith<S extends string, Start extends string & NonEmptyString<Start>> = S extends Append<Start, infer Rest> ? S extends Append<infer StartInstance, Rest> ? [StartInstance, Rest] : false : false;
/**
 * If the given string does not end with the given `End` type, returns false.
 * Otherwise, returns a tuple containing the start and the matched end.
 * @example
 * ```ts
 * EndsWith<'abcd', 'cd'> => ['ab', 'cd']
 * EndsWith<'abcd', 'a'> => false
 * EndsWith<'abcd', 'cd' | 'de'> => ['ab', 'cd']
 * EndsWith<'abcd', 'cd' | 'd'> => ['ab', 'cd'] | ['abc', 'd']
 * ```
 */
export type EndsWith<S extends string, End extends string & NonEmptyString<End>> = S extends Append<infer Start, End> ? S extends Append<Start, infer EndInstance> ? [Start, EndInstance] : false : false;
/**
 * Returns false if the given string does not contain the given `Middle` type,
 * or a 3-tuple containing the start, the matched middle, and the rest.
 * @example
 * ```ts
 * SplitAt<'abcd', 'bc'> => ['a', 'bc', 'd']
 * SplitAt<'abcd', 'ef'> => false
 * SplitAt<'abcd', 'b' | 'c'> => ['a', 'b', 'cd'] | ['ab', 'c', 'd']
 * ```
 */
export type SplitAt<S extends string, Middle extends string & NonEmptyString<Middle>> = S extends AppendTwo<infer Start, Middle, infer End> ? S extends AppendTwo<Start, infer MiddleInstance, End> ? [Start, MiddleInstance, End] : false : ['', '', S];
/**
 * Returns a string containing all the elements that do not match the given Sub type.
 * @example
 * ```ts
 * FilterNot<'abcd', 'b'> => 'acd'
 * FilterNot<'abcd', 'b' | 'd'> => 'ac'
 * ```
 */
export type FilterNot<S extends string, Sub extends string & NonEmptyString<Sub>> = FilterNotHelper<S, Sub, ''>;
type FilterNotHelper<S extends string, Sub extends string & NonEmptyString<Sub>, Result extends string> = S extends '' ? Result : S extends Append<Sub, infer Rest> ? FilterNotHelper<Rest, Sub, Result> : S extends Append<infer First, infer Rest> ? FilterNotHelper<Rest, Sub, Append<Result, First>> : '';
/**
 * Returns a string containing all the elements that match the given Sub type.
 * @example
 * ```ts
 * Filter<'abcd', 'b'> => 'b'
 * Filter<'abcd', 'b' | 'd'> => 'bd'
 * ```
 */
export type Filter<S extends string, Sub extends string & NonEmptyString<Sub>> = FilterHelper<S, Sub, ''>;
type FilterHelper<S extends string, Sub extends string & NonEmptyString<Sub>, Result extends string> = S extends '' ? Result : StartsWith<S, Sub> extends [infer SubInstance, infer Rest] ? FilterHelper<string & Rest, Sub, Append<Result, string & SubInstance>> : S extends Append<string, infer Rest> ? FilterHelper<Rest, Sub, Result> : '';
/**
 * Replaces, in the given string, all matches with Sub with the given Repl.
 * @example
 * ```ts
 * ReplaceAll<'abcba', 'b', '_'> => 'a_c_a'
 * ReplaceAll<'abcba', 'b' | 'c', '_'> => 'a___a'
 * ```
 */
export type ReplaceAll<S extends string, Sub extends string & NonEmptyString<Sub>, Repl extends string> = S extends '' ? '' : S extends Append<Sub, infer Rest> ? Append<Repl, ReplaceAll<Rest, Sub, Repl>> : S extends Append<infer Start, infer Rest> ? Append<Start, ReplaceAll<Rest, Sub, Repl>> : never;
/**
 * Replaces, in the given string, the first match with Sub with the given Repl.
 * Returns never if there was no match.
 * @example
 * ```ts
 * ReplaceFirst<'abcba', 'b', '_'> => 'a_cba'
 * ReplaceFirst<'abcba', 'b' | 'c', '_'> => 'a_cba'
 * ```
 */
export type ReplaceFirst<S extends string, Sub extends string & NonEmptyString<Sub>, Repl extends string> = S extends '' ? never : S extends Append<Sub, infer Rest> ? Append<Repl, Rest> : S extends Append<infer Start, infer Rest> ? Append<Start, ReplaceFirst<Rest, Sub, Repl>> : never;
/**
 * Replaces, in the given string, the last match with Sub with the given Repl.
 * Returns never if there was no match.
 * @example
 * ```ts
 * ReplaceLast<'abcba', 'b', '_'> => 'abc_a'
 * ReplaceLast<'abcba', 'b' | 'c', '_'> => 'abc_a'
 * ```
 */
export type ReplaceLast<S extends string, Sub extends string & NonEmptyString<Sub>, Repl extends string> = ReplaceLastHelper<S, Sub, Repl, false>;
type ReplaceLastHelper<S extends string, Sub extends string & NonEmptyString<Sub>, Repl extends string, Replaced extends boolean> = S extends '' ? Replaced extends true ? '' : never : StartsWith<S, Sub> extends [infer SubInstance, infer Rest] ? ReplaceLastHelper<string & Rest, Sub, Repl, true> extends infer Result ? Append<Result extends Rest ? string & Repl : string & SubInstance, string & Result> : never : S extends Append<infer Start, infer Rest> ? Append<Start, ReplaceLastHelper<Rest, Sub, Repl, Replaced>> : never;
/**
 * Returns the amount of times the given `Sub` type is encountered in the given string.
 * @example
 * ```ts
 * Count<'abcba', 'c'> => 1
 * Count<'abcba', 'a' | 'c'> => 3
 * Count<'abcba', 'q'> => 0
 * ```
 */
export type Count<S extends string, Sub extends string & NonEmptyString<Sub>> = CountHelper<S, Sub, 0>;
type CountHelper<S extends string, Sub extends string & NonEmptyString<Sub>, Result extends number> = S extends '' ? Result : S extends Append<Sub, infer Rest> ? CountHelper<Rest, Sub, Num.Inc<Result>> : S extends Append<string, infer Rest> ? CountHelper<Rest, Sub, Result> : Result;
/**
 * Returns true if the given string contains the given Amount (default 1) of Sub types.
 * @example
 * ```ts
 * Contains<'abcba', 'b'> => true
 * Contains<'abcba', 'b', 2> => true
 * Contains<'abcba', 'b', 3> => false
 * Contains<'abcba', 'q'> => false
 * ```
 */
export type Contains<S extends string, Sub extends string & NonEmptyString<Sub>, Amount extends number = 1> = Amount extends 0 ? true : S extends Append<Sub, infer Rest> ? Contains<Rest, Sub, Num.Decr<Amount>> : S extends Append<string, infer Rest> ? Contains<Rest, Sub, Amount> : false;
/**
 * Returns true if the given string does not contain the given Amount (default 1) of Sub types.
 * @example
 * ```ts
 * NotContains<'abcba', 'b'> => false
 * NotContains<'abcba', 'b', 2> => false
 * NotContains<'abcba', 'b', 3> => true
 * NotContains<'abcba', 'q'> => true
 * ```
 */
export type NotContains<S extends string, Sub extends string & NonEmptyString<Sub>, Amount extends number = 1> = Contains<S, Sub, Amount> extends false ? true : false;
export type RepeatTimes<S extends string, Sub extends string & NonEmptyString<Sub>> = RepeatTimesHelper<S, Sub, [0, '']>;
type RepeatTimesHelper<S extends string, Sub extends string & NonEmptyString<Sub>, Result extends [number, string]> = S extends '' ? [...Result, S] : StartsWith<S, Sub> extends [infer SubInstance, infer Rest] ? RepeatTimesHelper<string & Rest, Sub, [
    Num.Inc<Result[0]>,
    Append<Result[1], string & SubInstance>
]> : [...Result, S];
/**
 * Returns a tuple containing the matched part and the rest of the given string if the string
 * start repeats the given Sub at least N times.
 * @example
 * ```ts
 * RepeatAtLeastTimes<'aabc', 'a', 0> => ['', 'aabc']
 * RepeatAtLeastTimes<'aabc', 'a', 1> => ['a', 'abc']
 * RepeatAtLeastTimes<'aabc', 'a', 3> => false
 * RepeatAtLeastTimes<'aabc', 'a' | 'b', 3> => ['aab', 'c']
 * ```
 */
export type RepeatAtLeastTimes<S extends string, Sub extends string & NonEmptyString<Sub>, N extends number> = RepeatAtLeastTimesHelper<S, Sub, N, ''>;
type RepeatAtLeastTimesHelper<S extends string, Sub extends string & NonEmptyString<Sub>, N extends number, Processed extends string> = N extends 0 ? [Processed, S] : S extends '' ? false : StartsWith<S, Sub> extends [infer SubInstance, infer Rest] ? RepeatAtLeastTimesHelper<string & Rest, Sub, Num.Decr<N>, Append<Processed, string & SubInstance>> : false;
/**
 * Returns a tuple containing the matched part and the rest of the given string if the string
 * start repeats the given Sub at most N times.
 * @example
 * ```ts
 * RepeatAtMostTimes<'aabc', 'a', 0> => false
 * RepeatAtMostTimes<'aabc', 'a', 1> => false
 * RepeatAtMostTimes<'aabc', 'a', 3> => ['aa', 'bc']
 * RepeatAtMostTimes<'aabc', 'a' | 'b', 3> => ['aab', 'c']
 * ```
 */
export type RepeatAtMostTimes<S extends string, Sub extends string & NonEmptyString<Sub>, N extends number> = RepeatAtMostTimesHelper<S, Sub, N, ''>;
type RepeatAtMostTimesHelper<S extends string, Sub extends string & NonEmptyString<Sub>, N extends number, Processed extends string> = S extends Append<Sub, infer Rest> ? N extends 0 ? false : S extends Append<infer SubInstance, Rest> ? RepeatAtMostTimesHelper<Rest, Sub, Num.Decr<N>, Append<Processed, SubInstance>> : never : [Processed, S];
/**
 * Returns a tuple containing the matched part and the rest of the given string if the string
 * start repeats the given Sub exactly N times.
 * @example
 * ```ts
 * RepeatExactTimes<'aabc', 'a', 0> => false
 * RepeatExactTimes<'aabc', 'a', 1> => false
 * RepeatExactTimes<'aabc', 'a', 2> => ['aa', 'bc']
 * RepeatExactTimes<'aabc', 'a', 3> => false
 * RepeatExactTimes<'aabc', 'a' | 'b', 3> => ['aab', 'c']
 * ```
 */
export type RepeatExactTimes<S extends string, Sub extends string & NonEmptyString<Sub>, N extends number> = RepeatExactTimesHelper<S, Sub, N, ''>;
type RepeatExactTimesHelper<S extends string, Sub extends string & NonEmptyString<Sub>, N extends number, Processed extends string> = S extends Append<Sub, infer Rest> ? N extends 0 ? false : S extends Append<infer SubInstance, Rest> ? RepeatExactTimesHelper<Rest, Sub, Num.Decr<N>, Append<Processed, SubInstance>> : never : N extends 0 ? [Processed, S] : false;
/**
 * Returns the first N characters of the given string, or false if the string does
 * not have enough characters.
 * @example
 * ```ts
 * TakeStrict<'abcd', 2> => 'ab'
 * TakeStrict<'abcd', 5> => false
 * ```
 */
export type TakeStrict<S extends string, N extends number> = TakeStrictHelper<S, N, ''>;
type TakeStrictHelper<S extends string, N extends number, Result extends string> = N extends 0 ? Result : S extends Append<infer First, infer Rest> ? TakeStrictHelper<Rest, Num.Decr<N>, Append<Result, First>> : false;
/**
 * Returns the first N characters of the given string, or the given
 * string if it does not have enough characters.
 * @example
 * ```ts
 * Take<'abcd', 2> => 'ab'
 * Take<'abcd', 5> => 'abcd'
 * ```
 */
export type Take<S extends string, N extends number> = TakeHelper<S, N, ''>;
type TakeHelper<S extends string, N extends number, Result extends string> = N extends 0 ? Result : S extends Append<infer First, infer Rest> ? TakeHelper<Rest, Num.Decr<N>, Append<Result, First>> : Result;
/**
 * Returns part of the string as long as its parts match Sub.
 * @example
 * ```ts
 * TakeWhile<'aabc', 'a'> => 'aa'
 * TakeWhile<'aabc', 'a' | 'b'> => 'aab'
 * TakeWhile<'aabc', 'q'> => ''
 * ```
 */
export type TakeWhile<S extends string, Sub extends string & NonEmptyString<Sub>> = TakeWhileHelper<S, Sub, ''>;
type TakeWhileHelper<S extends string, Sub extends string & NonEmptyString<Sub>, Result extends string> = StartsWith<S, Sub> extends [infer SubInstance, infer Rest] ? TakeWhileHelper<string & Rest, Sub, Append<Result, string & SubInstance>> : Result;
/**
 * Skips part of the string as long as its parts match Sub.
 * @example
 * ```ts
 * DropWhile<'aabc', 'a'> => 'bc'
 * DropWhile<'aabc', 'a' | 'b'> => 'c'
 * DropWhile<'aabc', 'q'> => 'aabc'
 * ```
 */
export type DropWhile<S extends string, Sub extends string> = S extends Append<Sub, infer Rest> ? DropWhile<Rest, Sub> : S;
/**
 * Returns the given string reversed.
 * @example
 * ```ts
 * Reverse<'abcd'> => 'dcba'
 * ```
 */
export type Reverse<S extends string> = ReverseHelper<S, ''>;
type ReverseHelper<S extends string, Result extends string> = S extends Append<infer First, infer Rest> ? ReverseHelper<Rest, Append<First, Result>> : Result;
/**
 * Returns the given string without the first N characters, or false if the
 * string has less characters.
 * @example
 * ```ts
 * DropStrict<'abcd', 2> => 'cd'
 * DropStrict<'abcd', 5> => false
 * ```
 */
export type DropStrict<S extends string, N extends number> = N extends 0 ? S : S extends Append<string, infer Rest> ? DropStrict<Rest, Num.Decr<N>> : false;
/**
 * Returns the given string without the first N characters, or an empty string if the
 * string has less characters.
 * @example
 * ```ts
 * Drop<'abcd', 2> => 'cd'
 * Drop<'abcd', 5> => ''
 * ```
 */
export type Drop<S extends string, N extends number> = N extends 0 ? S : S extends Append<string, infer Rest> ? Drop<Rest, Num.Decr<N>> : S;
/**
 * Returns the first character of the given string, or false if the string is empty.
 * @example
 * ```ts
 * First<'abc'> => 'a'
 * First<''> => false
 * ```
 */
export type First<S extends string> = S extends Append<infer First, string> ? First : false;
/**
 * Returns all but the first character of the given string, or false if the string is empty.
 * @example
 * ```ts
 * Tail<'abcd'> => 'bcd'
 * Tail<''> => false
 * ```
 */
export type Tail<S extends string> = S extends Append<string, infer Rest> ? Rest : false;
/**
 * Returns all but the last character of the given string, or false if the string is empty.
 * @example
 * ```ts
 * Init<'abcd'> => 'abc'
 * Init<''> => false
 * ```
 */
export type Init<S extends string> = InitHelper<S, ''>;
type InitHelper<S extends string, Result extends string> = S extends Append<infer First, infer Rest> ? U.Extends<Rest, '', Result, InitHelper<Rest, Append<Result, First>>> : false;
/**
 * Returns the last character of the given string, or false if the string if empty.
 * @example
 * ```ts
 * Last<'abcd'> => 'd'
 * Last<''> => false
 * ```
 */
export type Last<S extends string> = S extends Append<infer First, infer Rest> ? U.Extends<Rest, '', First, Last<Rest>> : false;
/**
 * Returns the character in the given string at the given Index, or false if the index
 * is out of bounds.
 * @example
 * ```ts
 * CharAt<'abcd', 1> => 'b'
 * CharAt<'abcd', 5> => false
 * ```
 */
export type CharAt<S extends string, Index extends number> = S extends Append<infer Start, infer Rest> ? U.Extends<Index, 0, Start, CharAt<Rest, Num.Decr<Index>>> : false;
export {};