package containers

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package containers
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include module type of struct include String end
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.

Raise 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.

Raise 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.

Raise Invalid_argument if n < 0 or n > Sys.max_string_length.

val make : int -> char -> string

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

Raise Invalid_argument if n < 0 or n > Sys.max_string_length.

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.

Raise 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.

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

  • deprecated

    This is a deprecated alias of Bytes.fill.

val concat : string -> string list -> string

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

Raise Invalid_argument if the result is longer than Sys.max_string_length bytes.

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.

Raise 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.

Raise 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.

Raise 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.

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

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

Raise 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.

Raise 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 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
include module type of struct include CCString end

Basic String Utils

Consider using Containers_string.KMP for pattern search, or Regex libraries.

type 'a gen = unit -> 'a option
type 'a sequence = ('a -> unit) -> unit
type 'a klist = unit -> [ `Nil | `Cons of 'a * 'a klist ]

Common Signature

module type S = CCString.S

Strings

val equal : string -> string -> bool
val compare : string -> string -> int
val hash : string -> int
val init : int -> (int -> char) -> string

Analog to Array.init.

  • since 0.3.3
val of_gen : char gen -> string
val of_seq : char sequence -> string
val of_klist : char klist -> string
val of_list : char list -> string
val of_array : char array -> string
val to_array : string -> char array
val find : ?start:int -> sub:string -> string -> int

Find sub in string, returns its first index or -1. Should only be used with very small sub

val is_sub : sub:string -> int -> string -> int -> len:int -> bool

is_sub ~sub i s j ~len returns true iff the substring of sub starting at position i and of length len

val repeat : string -> int -> string

The same string, repeated n times

val prefix : pre:string -> string -> bool

prefix ~pre s returns true iff pre is a prefix of s

val suffix : suf:string -> string -> bool

suffix ~suf s returns true iff suf is a suffix of s

  • since 0.7
include S with type t := string
val length : string -> int
val blit : string -> int -> string -> int -> int -> unit

See String.blit

val fold : ('a -> char -> 'a) -> 'a -> string -> 'a

Fold on chars by increasing index.

  • since 0.7

Conversions

val to_gen : string -> char CCString.gen
val to_seq : string -> char CCString.sequence
val to_klist : string -> char CCString.klist
val to_list : string -> char list
val pp : Buffer.t -> string -> unit
val print : Format.formatter -> string -> unit

Splitting

module Split = CCString.Split

Slices

A contiguous part of a string

module Sub = CCString.Sub
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