Module ExtString.String

val empty : string

The empty string.

New Functions
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).

val find : string -> string -> int

find s x returns the starting index of the string x within the string s or raises Invalid_string if x is not a substring of s.

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

find s i x returns the starting index of the string x within the string s (starting search from position i) or raises Invalid_string if no such substring exists. find s x is equivalent to find_from s 0 x.

val split : string -> string -> string * string

split s sep splits the string s between the first occurrence of sep. raises Invalid_string if the separator is not found.

val nsplit : string -> string -> string list

nsplit s sep splits the string s into a list of strings which are separated by sep. nsplit "" _ returns the empty list.

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.

val lchop : string -> string

Returns the same string but without the first character. does nothing if the string is empty.

val rchop : string -> string

Returns the same string but without the last character. does nothing if the string is empty.

val of_int : int -> string

Returns the string representation of an int.

val of_float : float -> string

Returns the string representation of an float.

val of_char : char -> string

Returns a string containing one given character.

val to_int : string -> int

Returns the integer represented by the given string or raises Invalid_string if the string does not represent an integer.

val to_float : string -> float

Returns the float represented by the given string or raises Invalid_string if the string does not represent a float.

val ends_with : string -> suffix:string -> bool

ends_with s ~suffix returns true if the string s is ending with suffix.

val starts_with : string -> prefix:string -> bool

starts_with s ~prefix return true if s is starting with prefix.

val enum : string -> char Enum.t

Returns an enumeration of the characters of a string.

val of_enum : char Enum.t -> string

Creates a string from a character enumeration.

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

map f s returns a string where all characters c in s have been replaced by f c. *

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

map f s returns a string where all characters c in s have been replaced by f i s.[i]. *

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

Call f i s.[i] for every position i in string

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]

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) ...))

val explode : string -> char list

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

val implode : char list -> string

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

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".

val exists : string -> sub:string -> bool

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

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.

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

replace ~str ~sub ~by returns a tuple constisting 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 subtitution has taken place.

val trim : string -> string

Return a copy of the argument, without leading and trailing whitespace. The characters regarded as whitespace are: ' ', '\012', '\n', '\r', and '\t'. (Note that it is different from strip defaults).

Compatibility Functions
val uppercase_ascii : string -> string
val lowercase_ascii : string -> string
val capitalize_ascii : string -> string
val uncapitalize_ascii : string -> string
val split_on_char : char -> string -> string list
Older Functions

Please refer to the OCaml Manual for documentation of these functions.

val length : string -> int
val get : string -> int -> char
val set : Bytes.t -> int -> char -> unit
  • deprecated Use Bytes.set instead.
val create : int -> Bytes.t
  • deprecated Use Bytes.create instead.
val make : int -> char -> string
val copy : string -> string
  • deprecated
val sub : string -> int -> int -> string
val fill : Bytes.t -> int -> int -> char -> unit
  • deprecated Use Bytes.fill instead.
val blit : string -> int -> Bytes.t -> int -> int -> unit
val concat : string -> string list -> string
val iter : (char -> unit) -> string -> unit
val escaped : string -> string
val index : string -> char -> int
val index_opt : string -> char -> int option
val rindex : string -> char -> int
val rindex_opt : string -> char -> int option
val index_from : string -> int -> char -> int
val index_from_opt : string -> int -> char -> int option
val rindex_from : string -> int -> char -> int
val rindex_from_opt : string -> int -> char -> int option
val contains : string -> char -> bool
val contains_from : string -> int -> char -> bool
val rcontains_from : string -> int -> char -> bool
val uppercase : string -> string
  • deprecated Use String.uppercase_ascii instead.
val lowercase : string -> string
  • deprecated Use String.lowercase_ascii instead.
val capitalize : string -> string
  • deprecated Use String.capitalize_ascii instead.
val uncapitalize : string -> string
  • deprecated Use String.uncapitalize_ascii instead.
type t = string
val compare : t -> t -> int
val equal : t -> t -> bool
val to_seq : t -> char Seq.t

*_seq functions were introduced in OCaml 4.07.0, and are _not_ implemented in extlib for older OCaml versions

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