`val init : int -> (int -> char) -> string`

`init l f` returns the string of length `l` with the chars f 0 , f 1 , f 2 ... f (l-1).

Example: `String.init 256 char_of_int`

`val empty : string`

The empty string.

- since 3.4.0

`val is_empty : string -> bool`

`is_empty s` returns `true` if `s` is the empty string, `false` otherwise.

Usually a tad faster than comparing `s` with `""`.

Example (for some string `s`): `if String.is_empty s then "(Empty)" else s`

`val of_bytes : Stdlib.Bytes.t -> string`

Return a new string that contains the same bytes as the given byte sequence.

- since 3.4.0

`val to_bytes : string -> Stdlib.Bytes.t`

Return a new byte sequence that contains the same bytes as the given string.

- since 3.4.0

`val cat : string -> string -> string`

`cat s1 s2` concatenates s1 and s2 (equivalent to `s1 ^ s2`).

- raises `Invalid_argument`

  if the result is longer then than `Sys.max_string_length` bytes.

- since 3.4.0

`val for_all : (char -> bool) -> string -> bool`

`for_all p s` check if all chars in `s` satisfy the predicate `p`.

- since 3.4.0

`val length : string -> int`

Return the length (number of characters) of the given string.

`val get : string -> int -> char`

`String.get s n` returns character number `n` in string `s`. You can also write `s.[n]` instead of `String.get s n`.

- raises `Invalid_argument`

  if `n` not a valid character number in `s`.

`val make : int -> char -> string`

`String.make n c` returns a fresh string of length `n`, filled with the character `c`.

- raises `Invalid_argument`

  if `n < 0` or `n >` `Sys.max_string_length`.

`val sub : string -> int -> int -> string`

`String.sub s start len` returns a fresh string of length `len`, containing the substring of `s` that starts at position `start` and has length `len`.

- raises `Invalid_argument`

  if `start` and `len` do not designate a valid substring of `s`.

`val blit : string -> int -> Stdlib.Bytes.t -> int -> int -> unit`

`String.blit src srcoff dst dstoff len` copies `len` characters from string `src`, starting at character number `srcoff`, to the byte sequence `dst`, starting at character number `dstoff`.

- raises `Invalid_argument`

  if `srcoff` and `len` do not designate a valid substring of `src`, or if `dstoff` and `len` do not designate a valid substring of `dst`.

`val concat : string -> string list -> string`

`String.concat sep sl` concatenates the list of strings `sl`, inserting the separator string `sep` between each.

`val iter : (char -> unit) -> string -> unit`

`String.iter f s` applies function `f` in turn to all the characters of `s`. It is equivalent to `f s.[0]; f s.[1]; ...; f s.[String.length s - 1]; ()`.

`val mapi : (int -> char -> char) -> string -> string`

`String.mapi f s` calls `f` with each character of `s` and its index (in increasing index order) and stores the results in a new string that is returned.

- since 4.02.0

`val trim : string -> string`

Return a copy of the argument, without leading and trailing whitespace (according to `BatChar.is_whitespace`). The characters regarded as whitespace are: `' '`, `'\n'`, `'\r'`, `'\t'`, `'\012'` and `'\026'`. If there is no leading nor trailing whitespace character in the argument, return the original string itself, not a copy.

- since 4.00.0

`val escaped : string -> string`

Return a copy of the argument, with special characters represented by escape sequences, following the lexical conventions of OCaml. If there is no special character in the argument, return the original string itself, not a copy. Its inverse function is Scanf.unescaped.

`val index : string -> char -> int`

`String.index s c` returns the character number of the first occurrence of character `c` in string `s`.

- raises `Not_found`

  if `c` does not occur in `s`.

`val index_opt : string -> char -> int option`

`String.index_opt s c` returns the index of the first occurrence of character `c` in string `s`, or `None` if `c` does not occur in `s`.

- since 2.7.0

`val rindex : string -> char -> int`

`String.rindex s c` returns the character number of the last occurrence of character `c` in string `s`.

- raises `Not_found`

  if `c` does not occur in `s`.

`val rindex_opt : string -> char -> int option`

`String.rindex_opt s c` returns the index of the last occurrence of character `c` in string `s`, or `None` if `c` does not occur in `s`.

- since 2.7.0

`val index_from : string -> int -> char -> int`

`String.index_from s i c` returns the character number of the first occurrence of character `c` in string `s` after or at position `i`. `String.index s c` is equivalent to `String.index_from s 0 c`.

- raises `Invalid_argument`

  if `i` is not a valid position in `s`.

- raises `Not_found`

  if `c` does not occur in `s` after position `i`.

`val index_from_opt : string -> int -> char -> int option`

`String.index_from_opt s i c` returns the index of the first occurrence of character `c` in string `s` after position `i` or `None` if `c` does not occur in `s` after position `i`.

`String.index_opt s c` is equivalent to `String.index_from_opt s 0 c`. Raise `Invalid_argument` if `i` is not a valid position in `s`.

- since 2.7.0

`val rindex_from : string -> int -> char -> int`

`String.rindex_from s i c` returns the character number of the last occurrence of character `c` in string `s` before position `i+1`. `String.rindex s c` is equivalent to `String.rindex_from s (String.length s - 1) c`.

- raises `Invalid_argument`

  if `i+1` is not a valid position in `s`.

- raises `Not_found`

  if `c` does not occur in `s` before position `i+1`.

`val rindex_from_opt : string -> int -> char -> int option`

`String.rindex_from_opt s i c` returns the index of the last occurrence of character `c` in string `s` before position `i+1` or `None` if `c` does not occur in `s` before position `i+1`.

`String.rindex_opt s c` is equivalent to `String.rindex_from_opt s (String.length s - 1) c`.

Raise `Invalid_argument` if `i+1` is not a valid position in `s`.

- since 2.7.0

`val index_after_n : char -> int -> string -> int`

`index_after_n chr n str` returns the index of the character that comes immediately after the `n`-th occurrence of `chr` in `str`.

- Occurrences are numbered from 1: `n` = 1 returns the index of the character located immediately after the first occurrence of `chr`.
- `n` = 0 always returns `0`.
- If the `n`-th occurrence of `chr` is the last character of `str`, returns the length of `str`.

- raises `Invalid_argument`

  if `n < 0`.

- raises `Not_found`

  if there are strictly less than `n` occurrences of `chr` in `str`.

- since 2.9.0

`val contains : string -> char -> bool`

`String.contains s c` tests if character `c` appears in the string `s`.

`val contains_from : string -> int -> char -> bool`

`String.contains_from s start c` tests if character `c` appears in `s` after position `start`. `String.contains s c` is equivalent to `String.contains_from s 0 c`.

- raises `Invalid_argument`

  if `start` is not a valid position in `s`.

`val rcontains_from : string -> int -> char -> bool`

`String.rcontains_from s stop c` tests if character `c` appears in `s` before position `stop+1`.

- raises `Invalid_argument`

  if `stop < 0` or `stop+1` is not a valid position in `s`.

`val uppercase_ascii : string -> string`

Return a copy of the argument, with all lowercase letters translated to uppercase, using the US-ASCII character set.

- since 2.5.0

`val lowercase_ascii : string -> string`

Return a copy of the argument, with all uppercase letters translated to lowercase, using the US-ASCII character set.

- since 2.5.0

`val capitalize_ascii : string -> string`

Return a copy of the argument, with the first character set to uppercase, using the US-ASCII character set.

- since 2.5.0

`val uncapitalize_ascii : string -> string`

Return a copy of the argument, with the first character set to lowercase, using the US-ASCII character set.

- since 2.5.0

`type t = string`

An alias for the type of strings.

## Conversions

`val enum : string -> char BatEnum.t`

Returns an enumeration of the characters of a string. The behaviour is unspecified if the string is mutated while it is enumerated.

Examples: `"foo" |> String.enum |> List.of_enum = ['f'; 'o'; 'o']` `String.enum "a b c" // ((<>) ' ') |> String.of_enum = "abc"`

`val of_enum : char BatEnum.t -> string`

Creates a string from a character enumeration. Example: `['f'; 'o'; 'o'] |> List.enum |> String.of_enum = "foo"`

`val backwards : string -> char BatEnum.t`

Returns an enumeration of the characters of a string, from last to first.

Examples: `"foo" |> String.backwards |> String.of_enum = "oof"` `let rev s = String.backwards s |> String.of_enum`

`val of_backwards : char BatEnum.t -> string`

Build a string from an enumeration, starting with last character, ending with first.

Examples: `"foo" |> String.enum |> String.of_backwards = "oof"` `"foo" |> String.backwards |> String.of_backwards = "foo"` `let rev s = String.enum s |> String.of_backwards`

`val of_list : char list -> string`

Converts a list of characters to a string.

Example: `['c'; 'h'; 'a'; 'r'; 's'] |> String.of_list = "chars"`

`val to_list : string -> char list`

Converts a string to the list of its characters.

Example: `String.to_list "string" |> List.interleave ';' |> String.of_list = "s;t;r;i;n;g"`

`val of_int : int -> string`

Returns the string representation of an int.

Example: `String.of_int 56 = "56" && String.of_int (-1) = "-1"`

`val of_float : float -> string`

Returns the string representation of an float.

Example: `String.of_float 1.246 = "1.246"`

`val of_char : char -> string`

Returns a string containing one given character.

Example: `String.of_char 's' = "s"`

`val to_int : string -> int`

Returns the integer represented by the given string. This follows OCaml's int literal rules, so "0x" prefixes hexadecimal integers, "0o" for octal and "0b" for binary. Underscores within the number are allowed for readability but ignored.

Examples: `String.to_int "8_480" = String.to_int "0x21_20"` `try ignore(String.to_int "2,3"); false with Failure _ -> true`

- raises `Failure`

  if the string does not represent an integer.

`val to_float : string -> float`

Returns the float represented by the given string. Decimal points aren't required in the given string, as they are for float literals in OCaml, but otherwise the rules for float literals apply.

Examples: `String.to_float "12.34e-1" = String.to_float "1.234"` `String.to_float "1" = 1.` `try ignore(String.to_float ""); false with Failure _ -> true`

- raises `Failure`

  if the string does not represent a float.

## String traversals

`val map : (char -> char) -> string -> string`

`map f s` returns a string where all characters `c` in `s` have been replaced by `f c`.

Example: `String.map Char.uppercase "Five" = "FIVE"` *

`val fold_left : ('a -> char -> 'a) -> 'a -> string -> 'a`

`fold_left f a s` is `f (... (f (f a s.[0]) s.[1]) ...) s.[n-1]`

Examples: `String.fold_left (fun li c -> c::li) [] "foo" = ['o';'o';'f']` `String.fold_left max 'a' "apples" = 's'`

`val fold_lefti : ('a -> int -> char -> 'a) -> 'a -> string -> 'a`

As `fold_left`, but with the index of the element as additional argument

- since 2.3.0

`val fold_right : (char -> 'a -> 'a) -> string -> 'a -> 'a`

`fold_right f s b` is `f s.[0] (f s.[1] (... (f s.[n-1] b) ...))`

Examples: `String.fold_right List.cons "foo" [] = ['f';'o';'o']` `String.fold_right (fun c a -> if c = ' ' then a+1 else a) "a b c" 0 = 2`

`val fold_righti : (int -> char -> 'a -> 'a) -> string -> 'a -> 'a`

As `fold_right`, but with the index of the element as additional argument

- since 2.3.0

`val filter : (char -> bool) -> string -> string`

`filter f s` returns a copy of string `s` in which only characters `c` such that `f c = true` remain.

Example: `String.filter ((<>) ' ') "a b c" = "abc"`

`val filter_map : (char -> char option) -> string -> string`

`filter_map f s` calls `(f a0) (f a1).... (f an)` where `a0..an` are the characters of `s`. It returns the string of characters `ci` such as `f ai = Some ci` (when `f` returns `None`, the corresponding element of `s` is discarded).

Example: `String.filter_map (function 'a'..'z' as c -> Some (Char.uppercase c) | _ -> None) "a b c" = "ABC"`

`val iteri : (int -> char -> unit) -> string -> unit`

`String.iteri f s` is equivalent to `f 0 s.[0]; f 1 s.[1]; ...; f len s.[len]` where `len` is length of string `s`. Example:

     let letter_positions word =
      let positions = Array.make 256 [] in
      let count_letter pos c =
        positions.(int_of_char c) <- pos :: positions.(int_of_char c) in
      String.iteri count_letter word;
      Array.mapi (fun c pos -> (char_of_int c, List.rev pos)) positions
      |> Array.to_list
      |> List.filter (fun (c,pos) -> pos <> [])
      in
      letter_positions "hello" = ['e',[1]; 'h',[0]; 'l',[2;3]; 'o',[4] ]

## Finding

`val find : string -> string -> int`

`find s x` returns the starting index of the first occurrence of string `x` within string `s`.

Note This implementation is optimized for short strings.

- raises `Not_found`

  if `x` is not a substring of `s`.

Example: `String.find "foobarbaz" "bar" = 3`

`val find_from : string -> int -> string -> int`

`find_from s pos x` behaves as `find s x` but starts searching at position `pos`. `find s x` is equivalent to `find_from s 0 x`.

- raises `Not_found`

  if not substring is found

- raises `Invalid_argument`

  if `pos` is not a valid position in the string.

Example: `String.find_from "foobarbaz" 4 "ba" = 6`

`val rfind : string -> string -> int`

`rfind s x` returns the starting index of the last occurrence of string `x` within string `s`.

Note This implementation is optimized for short strings.

- raises `Not_found`

  if `x` is not a substring of `s`.

Example: `String.rfind "foobarbaz" "ba" = 6`

`val rfind_from : string -> int -> string -> int`

`rfind_from s pos x` behaves as `rfind s x` but starts searching from the right at position `pos + 1`. `rfind s x` is equivalent to `rfind_from s (String.length s - 1) x`.

Beware, it search between the beginning of the string to the position `pos + 1`, not between `pos + 1` and the end.

- raises `Not_found`

  if not substring is found

- raises `Invalid_argument`

  if `pos` is not a valid position in the string.

Example: `String.rfind_from "foobarbaz" 6 "ba" = 6`

`val find_all : string -> string -> int BatEnum.t`

`find_all s x` enumerates positions of `s` at which `x` occurs. Example: `find_all "aabaabaa" "aba" |> List.of_enum` will return the list `[1; 4]`.

- since 2.2.0

`val count_string : string -> string -> int`

`count_string s x` count how many times `x` is found in `s`.

- since 2.9.0

`val ends_with : string -> string -> bool`

`ends_with s x` returns `true` if the string `s` is ending with `x`, `false` otherwise.

Example: `String.ends_with "foobarbaz" "rbaz" = true`

`val starts_with : string -> string -> bool`

`starts_with s x` returns `true` if `s` is starting with `x`, `false` otherwise.

Example: `String.starts_with "foobarbaz" "fooz" = false`

`val starts_with_stdlib : prefix:string -> string -> bool`

Equivalent to `starts_with` but the prefix is a labelled parameter.

- since 3.4.0

`val ends_with_stdlib : suffix:string -> string -> bool`

Equivalent to `ends_with` but the suffix is a labelled parameter.

- since 3.4.0

`val exists : string -> string -> bool`

`exists str sub` returns true if `sub` is a substring of `str` or false otherwise.

Example: `String.exists "foobarbaz" "obar" = true`

`val exists_stdlib : (char -> bool) -> string -> bool`

`exists_stdlib p str` check if at least one char of `str` satisfies the predicate `p`.

- since 3.4.0

`val count_char : string -> char -> int`

`count_char str c` returns the number of times `c` is used in `str`.

## Transformations

`val lchop : ?n:int -> string -> string`

Returns the same string but without the first `n` characters. By default `n` is 1.

- raises `Invalid_argument`

  If `n` is strictly less than zero. If the string has `n` or less characters, returns the empty string.

Example: `String.lchop "Weeble" = "eeble"` `String.lchop ~n:3 "Weeble" = "ble"` `String.lchop ~n:1000 "Weeble" = ""`

`val rchop : ?n:int -> string -> string`

Returns the same string but without the last `n` characters. By default `n` is 1.

- raises `Invalid_argument`

  If `n` is strictly less than zero. If the string has `n` or less characters , returns the empty string.

Example: `String.rchop "Weeble" = "Weebl"` `String.rchop ~n:3 "Weeble" = "Wee"` `String.rchop ~n:1000 "Weeble" = ""`

`val chop : ?l:int -> ?r:int -> string -> string`

Returns the same string but with the first `l` characters on the left and the first `r` characters on the right removed. By default, `l` and `r` are both 1.

`chop ~l ~r s` is equivalent to `lchop ~n:l (rchop ~n:r s)`.

- raises `Invalid_argument`

  if either `l` or `r` is less than zero.

Examples: `String.chop "\"Weeble\"" = "Weeble"` `String.chop ~l:2 ~r:3 "01234567" = "234"`

`val quote : string -> string`

Add quotes around a string and escape any quote or escape appearing in that string. This function is used typically when you need to generate source code from a string.

Examples: `String.quote "foo" = "\"foo\""` `String.quote "\"foo\"" = "\"\\\"foo\\\"\""` `String.quote "\n" = "\"\\n\""` etc.

More precisely, the returned string conforms to the OCaml syntax: if printed, it outputs a representation of the input string as an OCaml string litteral.

`val left : string -> int -> string`

`left r len` returns the string containing the `len` first characters of `r`. If `r` contains less than `len` characters, it returns `r`.

Examples: `String.left "Weeble" 4 = "Weeb"` `String.left "Weeble" 0 = ""` `String.left "Weeble" 10 = "Weeble"`

`val right : string -> int -> string`

`right r len` returns the string containing the `len` last characters of `r`. If `r` contains less than `len` characters, it returns `r`.

Example: `String.right "Weeble" 4 = "eble"`

`val head : string -> int -> string`

as `left`

`val tail : string -> int -> string`

`tail r pos` returns the string containing all but the `pos` first characters of `r`

Example: `String.tail "Weeble" 4 = "le"`

`val strip : ?chars:string -> string -> string`

Returns the string without the chars if they are at the beginning or at the end of the string. By default chars are " \t\r\n".

Examples: `String.strip " foo " = "foo"` `String.strip ~chars:" ,()" " boo() bar()" = "boo() bar"`

`val replace_chars : (char -> string) -> string -> string`

`replace_chars f s` returns a string where all chars `c` of `s` have been replaced by the string returned by `f c`.

Example: `String.replace_chars (function ' ' -> "(space)" | c -> String.of_char c) "foo bar" = "foo(space)bar"`

`val replace : str:string -> sub:string -> by:string -> bool * string`

`replace ~str ~sub ~by` returns a tuple consisting of a boolean and a string where the first occurrence of the string `sub` within `str` has been replaced by the string `by`. The boolean is true if a substitution has taken place.

Example: `String.replace "foobarbaz" "bar" "rab" = (true, "foorabbaz")`

`val nreplace : str:string -> sub:string -> by:string -> string`

`nreplace ~str ~sub ~by` returns a string obtained by iteratively replacing each occurrence of `sub` by `by` in `str`, from right to left. It returns a copy of `str` if `sub` has no occurrence in `str`.

Example: `nreplace ~str:"bar foo aaa bar" ~sub:"aa" ~by:"foo" = "bar foo afoo bar"`

`val repeat : string -> int -> string`

`repeat s n` returns `s ^ s ^ ... ^ s`

Example: `String.repeat "foo" 4 = "foofoofoofoo"`

`val rev : string -> string`

`rev s` returns the reverse of string `s`

- since 2.1

## In-Place Transformations

`val rev_in_place : Stdlib.Bytes.t -> unit`

`rev_in_place s` mutates the byte sequence `s`, so that its new value is the mirror of its old one: for instance if s contained `"Example!"`, after the mutation it will contain `"!elpmaxE"`.

`val in_place_mirror : Stdlib.Bytes.t -> unit`

- deprecated

  Use `String.rev_in_place` instead

## Splitting around

`val split_on_char : char -> string -> string list`

`String.split_on_char sep s` returns the list of all (possibly empty) substrings of `s` that are delimited by the `sep` character.

The function's output is specified by the following invariants:

- The list is not empty.
- Concatenating its elements using `sep` as a separator returns a string equal to the input (`String.concat (String.make 1 sep) (String.split_on_char sep s) = s`).
- No string in the result contains the `sep` character.

Note: prior to 2.11.0 `split_on_char _ ""` used to return an empty list.

- since 2.5.3

`val split : string -> by:string -> string * string`

`split s sep` splits the string `s` between the first occurrence of `sep`, and returns the two parts before and after the occurrence (excluded).

- raises `Not_found`

  if the separator is not found.

Examples: `String.split "abcabcabc" "bc" = ("a","abcabc")` `String.split "abcabcabc" "" = ("","abcabcabc")`

`val rsplit : string -> by:string -> string * string`

`rsplit s sep` splits the string `s` between the last occurrence of `sep`, and returns the two parts before and after the occurrence (excluded).

- raises `Not_found`

  if the separator is not found.

Example: `String.rsplit "abcabcabc" "bc" = ("abcabca","")`

`val nsplit : string -> by:string -> string list`

`nsplit s sep` splits the string `s` into a list of strings which are separated by `sep` (excluded). `nsplit "" _` returns a single empty string. Note: prior to 2.11.0 `nsplit "" _` used to return an empty list.

Example: `String.nsplit "abcabcabc" "bc" = ["a"; "a"; "a"; ""]`

- deprecated

  use `split_on_string`

`val split_on_string : by:string -> string -> string list`

`split_on_string sep s` splits the string `s` into a list of strings which are separated by `sep` (excluded). `split_on_string _ ""` returns a single empty string. Note: `split_on_string sep s` is identical to `nsplit s sep` but for empty strings.

Example: `String.split_on_string "bc" "abcabcabc" = ["a"; "a"; "a"; ""]`

- since 2.11.0

`val cut_on_char : char -> int -> string -> string`

Similar to Unix `cut`. `cut_on_char chr n str` returns the substring of `str` located strictly between the `n`-th occurrence of `chr` and the `n+1`-th one.

- Occurrences of `chr` are numbered from 1.
- If `n = 0`, returns the substring from the beginning of `str` to the first occurrence of `chr`.
- If there are exactly `n` occurrences of `chr` in `str`, returns the substring between the last occurrence of `chr` and the end of `str`.
- These behaviours cumulate: if `n` equals `0` and `chr` is absent from `str`, returns the full string `str`.

Remark: `cut_on_char` can return the empty string. Examples of this behaviour are `cut_on_char ',' 1 "foo,,bar"` and `cut_on_char ',' 0 ",foo"`.

- raises `Not_found`

  if there are strictly less than `n` occurrences of `chr` in str.

- raises `Invalid_argument`

  if `n < 0`.

- since 2.9.0

`val join : string -> string list -> string`

Same as `concat`

`val slice : ?first:int -> ?last:int -> string -> string`

`slice ?first ?last s` returns a "slice" of the string which corresponds to the characters `s.[first]`, `s.[first+1]`, ..., `s[last-1]`. Note that the character at index `last` is not included! If `first` is omitted it defaults to the start of the string, i.e. index 0, and if `last` is omitted is defaults to point just past the end of `s`, i.e. `length s`. Thus, `slice s` is equivalent to `copy s`.

Negative indexes are interpreted as counting from the end of the string. For example, `slice ~last:(-2) s` will return the string `s`, but without the last two characters.

This function never raises any exceptions. If the indexes are out of bounds they are automatically clipped.

Example: `String.slice ~first:1 ~last:(-3) " foo bar baz" = "foo bar "`

`val splice : string -> int -> int -> string -> string`

`String.splice s off len rep` cuts out the section of `s` indicated by `off` and `len` and replaces it by `rep`

Negative indexes are interpreted as counting from the end of the string. If `off+len` is greater than `length s`, the end of the string is used, regardless of the value of `len`.

If `len` is zero or negative, `rep` is inserted at position `off` without replacing any of `s`.

Example: `String.splice "foo bar baz" 3 5 "XXX" = "fooXXXbaz"`

`val explode : string -> char list`

`explode s` returns the list of characters in the string `s`.

Example: `String.explode "foo" = ['f'; 'o'; 'o']`

`val implode : char list -> string`

`implode cs` returns a string resulting from concatenating the characters in the list `cs`.

Example: `String.implode ['b'; 'a'; 'r'] = "bar"`

## Iterators

`val to_seq : t -> char Stdlib.Seq.t`

Iterate on the string, in increasing index order. Modifications of the string during iteration will be reflected in the iterator.

- since 2.10.0 and OCaml 4.07

`val to_seqi : t -> (int * char) Stdlib.Seq.t`

Iterate on the string, in increasing order, yielding indices along chars

- since 2.10.0 and OCaml 4.07

`val of_seq : char Stdlib.Seq.t -> t`

Create a string from the generator

- since 2.10.0 and OCaml 4.07

## Binary decoding of integers

The functions in this section binary decode integers from strings.

All following functions raise `Invalid_argument` if the characters needed at index `i` to decode the integer are not available.

Little-endian (resp. big-endian) encoding means that least (resp. most) significant bytes are stored first. Big-endian is also known as network byte order. Native-endian encoding is either little-endian or big-endian depending on `Sys.big_endian`.

32-bit and 64-bit integers are represented by the `int32` and `int64` types, which can be interpreted either as signed or unsigned numbers.

8-bit and 16-bit integers are represented by the `int` type, which has more bits than the binary encoding. These extra bits are sign-extended (or zero-extended) for functions which decode 8-bit or 16-bit integers and represented them with `int` values.

`val get_uint8 : string -> int -> int`

`get_uint8 b i` is `b`'s unsigned 8-bit integer starting at character index `i`.

- since 3.4.0

`val get_int8 : string -> int -> int`

`get_int8 b i` is `b`'s signed 8-bit integer starting at character index `i`.

- since 3.4.0 and OCaml 4.08

`val get_uint16_ne : string -> int -> int`

`get_uint16_ne b i` is `b`'s native-endian unsigned 16-bit integer starting at character index `i`.

- since 3.4.0 and OCaml 4.08

`val get_uint16_be : string -> int -> int`

`get_uint16_be b i` is `b`'s big-endian unsigned 16-bit integer starting at character index `i`.

- since 3.4.0 and OCaml 4.08

`val get_uint16_le : string -> int -> int`

`get_uint16_le b i` is `b`'s little-endian unsigned 16-bit integer starting at character index `i`.

- since 3.4.0 and OCaml 4.08

`val get_int16_ne : string -> int -> int`

`get_int16_ne b i` is `b`'s native-endian signed 16-bit integer starting at character index `i`.

- since 3.4.0 and OCaml 4.08

`val get_int16_be : string -> int -> int`

`get_int16_be b i` is `b`'s big-endian signed 16-bit integer starting at character index `i`.

- since 3.4.0 and OCaml 4.08

`val get_int16_le : string -> int -> int`

`get_int16_le b i` is `b`'s little-endian signed 16-bit integer starting at character index `i`.

- since 3.4.0 and OCaml 4.08

`val get_int32_ne : string -> int -> int32`

`get_int32_ne b i` is `b`'s native-endian 32-bit integer starting at character index `i`.

- since 3.4.0 and OCaml 4.08

`val hash : t -> int`

An unseeded hash function for strings, with the same output value as `Hashtbl.hash`. This function allows this module to be passed as argument to the functor `Hashtbl.Make`.

- since 3.6.0 and OCaml 5.0.0

`val seeded_hash : int -> t -> int`

A seeded hash function for strings, with the same output value as `Hashtbl.seeded_hash`. This function allows this module to be passed as argument to the functor `Hashtbl.MakeSeeded`.

- since 3.6.0 and OCaml 5.0.0

`val get_int32_be : string -> int -> int32`

`get_int32_be b i` is `b`'s big-endian 32-bit integer starting at character index `i`.

- since 3.4.0 and OCaml 4.08

`val get_int32_le : string -> int -> int32`

`get_int32_le b i` is `b`'s little-endian 32-bit integer starting at character index `i`.

- since 3.4.0 and OCaml 4.08

`val get_int64_ne : string -> int -> int64`

`get_int64_ne b i` is `b`'s native-endian 64-bit integer starting at character index `i`.

- since 3.4.0 and OCaml 4.08

`val get_int64_be : string -> int -> int64`

`get_int64_be b i` is `b`'s big-endian 64-bit integer starting at character index `i`.

- since 3.4.0 and OCaml 4.08

`val get_int64_le : string -> int -> int64`

`get_int64_le b i` is `b`'s little-endian 64-bit integer starting at character index `i`.

- since 3.4.0 and OCaml 4.08

## UTF decoding and validations

- since 4.14

### UTF-8

`val get_utf_8_uchar : t -> int -> Stdlib.Uchar.utf_decode`

`get_utf_8_uchar b i` decodes an UTF-8 character at index `i` in `b`.

`val is_valid_utf_8 : t -> bool`

`is_valid_utf_8 b` is `true` if and only if `b` contains valid UTF-8 data.

### UTF-16BE

`val get_utf_16be_uchar : t -> int -> Stdlib.Uchar.utf_decode`

`get_utf_16be_uchar b i` decodes an UTF-16BE character at index `i` in `b`.

`val is_valid_utf_16be : t -> bool`

`is_valid_utf_16be b` is `true` if and only if `b` contains valid UTF-16BE data.

### UTF-16LE

`val get_utf_16le_uchar : t -> int -> Stdlib.Uchar.utf_decode`

`get_utf_16le_uchar b i` decodes an UTF-16LE character at index `i` in `b`.

`val is_valid_utf_16le : t -> bool`

`is_valid_utf_16le b` is `true` if and only if `b` contains valid UTF-16LE data.

## Comparisons

`val equal : t -> t -> bool`

String equality

`val ord : t -> t -> BatOrd.order`

Ordering function for strings, see `BatOrd`

`val compare : t -> t -> int`

The comparison function for strings, with the same specification as `Pervasives.compare`. Along with the type `t`, this function `compare` allows the module `String` to be passed as argument to the functors `Set.Make` and `Map.Make`.

Example: `String.compare "FOO" "bar" = -1` i.e. "FOO" < "bar"

`val icompare : t -> t -> int`

Compare two strings, case-insensitive.

Example: `String.icompare "FOO" "bar" = 1` i.e. "foo" > "bar"

`module IString : BatInterfaces.OrderedType with type t = t`

uses icompare as ordering function

`val numeric_compare : t -> t -> int`

Compare two strings, sorting "abc32def" before "abc210abc".

Algorithm: splits both strings into lists of (strings of digits) or (strings of non digits) (`["abc"; "32"; "def"]` and `["abc"; "210"; "abc"]`) Then both lists are compared lexicographically by comparing elements numerically when both are numbers or lexicographically in other cases.

Example: `String.numeric_compare "xx32" "xx210" < 0`

`module NumString : BatInterfaces.OrderedType with type t = t`

uses numeric_compare as its ordering function

`val edit_distance : t -> t -> int`

Edition distance (also known as "Levenshtein distance"). See wikipedia

- since 2.2.0

## Boilerplate code

### Printing

`val print : 'a BatInnerIO.output -> string -> unit`

Print a string.

Example: `String.print stdout "foo\n"`

`val println : 'a BatInnerIO.output -> string -> unit`

Print a string, end the line.

Example: `String.println stdout "foo"`

`val print_quoted : 'a BatInnerIO.output -> string -> unit`

Print a string, with quotes as added by the `quote` function.

`String.print_quoted stdout "foo"` prints `"foo"` (with the quotes).

`String.print_quoted stdout "\"bar\""` prints `"\"bar\""` (with the quotes).

`String.print_quoted stdout "\n"` prints `"\n"` (not the escaped character, but `'\'` then `'n'`).

`module Exceptionless : sig ... end`

Exceptionless counterparts for error-raising operations

`module Cap : sig ... end`

Capabilities for strings.

`val spellcheck : ?max_dist:(string -> int) -> ((string -> unit) -> unit) -> string -> string list`