package stdcompat

  1. Overview
  2. Docs
include module type of struct include String end
val length : string -> int

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

val get : string -> int -> char

String.get s n returns the character at index n in string s. You can also write s.[n] instead of String.get s n.

  • raises Invalid_argument

    if n not a valid index in s.

val set : bytes -> int -> char -> unit

String.set s n c modifies byte sequence s in place, replacing the byte at index n with c. You can also write s.[n] <- c instead of String.set s n c.

  • raises Invalid_argument

    if n is not a valid index in s.

  • deprecated

    This is a deprecated alias of Bytes.set.

val create : int -> bytes

String.create n returns a fresh byte sequence of length n. The sequence is uninitialized and contains arbitrary bytes.

val make : int -> char -> string

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

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

String.init n f returns a string of length n, with character i initialized to the result of f i (called in increasing index order).

  • since 4.02.0
val copy : string -> string

Return a copy of the given string.

  • deprecated

    Because strings are immutable, it doesn't make much sense to make identical copies of them.

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 fill : bytes -> int -> int -> char -> unit

String.fill s start len c modifies byte sequence s in place, replacing len bytes with c, starting at start.

  • raises Invalid_argument

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

  • deprecated

    This is a deprecated alias of Bytes.fill.

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

Same as String.iter, but the function is applied to the index of the element as first argument (counting from 0), and the character itself as second argument.

  • since 4.00.0
val map : (char -> char) -> string -> string

String.map f s applies function f in turn to all the characters of s (in increasing index order) and stores the results in a new string that is returned.

  • since 4.00.0
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. The characters regarded as whitespace are: ' ', '\012', '\n', '\r', and '\t'. If there is neither 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. All characters outside the ASCII printable range (32..126) are escaped, as well as backslash and double-quote.

If there is no special character in the argument that needs escaping, return the original string itself, not a copy.

  • raises Invalid_argument

    if the result is longer than Sys.max_string_length bytes.

    The function Scanf.unescaped is a left inverse of escaped, i.e. Scanf.unescaped (escaped s) = s for any string s (unless escape s fails).

val index : string -> char -> int

String.index s c returns the index 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 4.05
val rindex : string -> char -> int

String.rindex s c returns the index 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 4.05
val index_from : string -> int -> char -> int

String.index_from s i c returns the index of the first occurrence of character c in string s after 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.

  • raises Invalid_argument

    if i is not a valid position in s.

  • since 4.05
val rindex_from : string -> int -> char -> int

String.rindex_from s i c returns the index 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.

  • raises Invalid_argument

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

  • since 4.05
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 : string -> string

Return a copy of the argument, with all lowercase letters translated to uppercase, including accented letters of the ISO Latin-1 (8859-1) character set.

  • deprecated

    Functions operating on Latin-1 character set are deprecated.

val lowercase : string -> string

Return a copy of the argument, with all uppercase letters translated to lowercase, including accented letters of the ISO Latin-1 (8859-1) character set.

  • deprecated

    Functions operating on Latin-1 character set are deprecated.

val capitalize : string -> string

Return a copy of the argument, with the first character set to uppercase, using the ISO Latin-1 (8859-1) character set..

  • deprecated

    Functions operating on Latin-1 character set are deprecated.

val uncapitalize : string -> string

Return a copy of the argument, with the first character set to lowercase, using the ISO Latin-1 (8859-1) character set..

  • deprecated

    Functions operating on Latin-1 character set are deprecated.

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 4.03.0
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 4.03.0
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 4.03.0
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 4.03.0
type t = string

An alias for the type of strings.

val compare : t -> t -> int

The comparison function for strings, with the same specification as Stdlib.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.

val equal : t -> t -> bool

The equal function for strings.

  • since 4.03.0
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.
  • since 4.04.0

Iterators

val to_seq : t -> char Seq.t

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

  • since 4.07
val to_seqi : t -> (int * char) Seq.t

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

  • since 4.07
val of_seq : char Seq.t -> t

Create a string from the generator

  • since 4.07
val empty : string
val of_bytes : bytes -> string
val to_bytes : string -> bytes
val cat : string -> string -> string
val starts_with : prefix:string -> string -> bool
val ends_with : suffix:string -> string -> bool
val fold_left : ('a -> char -> 'a) -> 'a -> string -> 'a
val fold_right : (char -> 'a -> 'a) -> string -> 'a -> 'a
val for_all : (char -> bool) -> string -> bool
val exists : (char -> bool) -> string -> bool
val get_uint8 : string -> int -> int
val get_int8 : string -> int -> int
val get_uint16_ne : string -> int -> int
val get_uint16_be : string -> int -> int
val get_uint16_le : string -> int -> int
val get_int16_ne : string -> int -> int
val get_int16_be : string -> int -> int
val get_int16_le : string -> int -> int
val get_int32_ne : string -> int -> int32
val get_int32_be : string -> int -> int32
val get_int32_le : string -> int -> int32
val get_int64_ne : string -> int -> int64
val get_int64_be : string -> int -> int64
val get_int64_le : string -> int -> int64
val get_utf_8_uchar : string -> int -> int
val is_valid_utf_8 : string -> bool
val get_utf_16be_uchar : string -> int -> int
val is_valid_utf_16be : string -> bool
val get_utf_16le_uchar : string -> int -> int
val is_valid_utf_16le : string -> bool