Module CCString

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 : sig ... end

Strings

include module type of sig ... end
external length : string ‑> int = "%string_length"
external get : string ‑> int ‑> char = "%string_safe_get"
external set : bytes ‑> int ‑> char ‑> unit = "%string_safe_set"
  • Deprecated Use Bytes.set instead.
external create : int ‑> bytes = "caml_create_string"
  • Deprecated Use Bytes.create instead.
val make : int ‑> char ‑> string
val init : int ‑> (int ‑> char) ‑> string
val copy : string ‑> string
val sub : string ‑> int ‑> int ‑> string
val fill : bytes ‑> int ‑> int ‑> char ‑> unit
  • Deprecated Use Bytes.fill instead.
val blit : string ‑> int ‑> bytes ‑> int ‑> int ‑> unit
val concat : string ‑> string list ‑> string
val iter : (char ‑> unit) ‑> string ‑> unit
val iteri : (int ‑> char ‑> unit) ‑> string ‑> unit
val map : (char ‑> char) ‑> string ‑> string
val mapi : (int ‑> char ‑> char) ‑> string ‑> string
val trim : string ‑> string
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.
val uppercase_ascii : string ‑> string
val lowercase_ascii : string ‑> string
val capitalize_ascii : string ‑> string
val uncapitalize_ascii : string ‑> string
type t = string
val compare : t ‑> t ‑> int
val equal : t ‑> t ‑> bool
val split_on_char : char ‑> string ‑> string list
external unsafe_get : string ‑> int ‑> char = "%string_unsafe_get"
external unsafe_set : bytes ‑> int ‑> char ‑> unit = "%string_unsafe_set"
external unsafe_blit : string ‑> int ‑> bytes ‑> int ‑> int ‑> unit = "caml_blit_string"
external unsafe_fill : bytes ‑> int ‑> int ‑> char ‑> unit = "caml_fill_string"
val equal : string ‑> string ‑> bool

Equality function on strings.

val compare : string ‑> string ‑> int
val is_empty : string ‑> bool

is_empty s returns true iff s is empty (i.e. its length is 0).

val hash : string ‑> int
val init : int ‑> (int ‑> char) ‑> string

Like Array.init.

val rev : string ‑> string

rev s returns the reverse of s.

val pad : ?⁠side:[ `Left | `Right ] ‑> ?⁠c:char ‑> int ‑> string ‑> string

pad n str ensures that str is at least n bytes long, and pads it on the side with c if it's not the case.

val of_char : char ‑> string

of_char 'a' is "a".

val of_gen : char gen ‑> string

Convert a gen of characters to a string.

val of_seq : char sequence ‑> string

Convert a sequence of characters to a string.

val of_klist : char klist ‑> string

Convert a klist of characters to a string.

val of_list : char list ‑> string

Convert a list of characters to a string.

val of_array : char array ‑> string

Convert an array of characters to a string.

val to_array : string ‑> char array

Return the array of characters contained in the string.

val find : ?⁠start:int ‑> sub:string ‑> string ‑> int

Find sub in string, returns its first index or -1.

val find_all : ?⁠start:int ‑> sub:string ‑> string ‑> int gen

find_all ~sub s finds all occurrences of sub in s, even overlapping instances.

val find_all_l : ?⁠start:int ‑> sub:string ‑> string ‑> int list

find_all_l ~sub s finds all occurrences of sub in s and returns them in a list.

val mem : ?⁠start:int ‑> sub:string ‑> string ‑> bool

mem ~sub s is true iff sub is a substring of s.

val rfind : sub:string ‑> string ‑> int

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

val replace : ?⁠which:[ `Left | `Right | `All ] ‑> sub:string ‑> by:string ‑> string ‑> string

replace ~sub ~by s replaces some occurrences of sub by by in s.

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 is a substring of s starting at position j.

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.

val chop_prefix : pre:string ‑> string ‑> string option

chop_prefix ~pre s removes pre from s if pre really is a prefix of s, returns None otherwise.

val chop_suffix : suf:string ‑> string ‑> string option

chop_suffix ~suf s removes suf from s if suf really is a suffix of s, returns None otherwise.

val take : int ‑> string ‑> string

take n s keeps only the n first chars of s.

val drop : int ‑> string ‑> string

drop n s removes the n first chars of s.

val take_drop : int ‑> string ‑> string * string

take_drop n s = take n s, drop n s.

val lines : string ‑> string list

lines s returns a list of the lines of s (splits along '\n').

val lines_gen : string ‑> string gen

lines_gen s returns a generator of the lines of s (splits along '\n').

val concat_gen : sep:string ‑> string gen ‑> string

concat_gen ~sep g concatenates all strings of g, separated with sep.

val unlines : string list ‑> string

unlines l concatenates all strings of l, separated with '\n'.

val unlines_gen : string gen ‑> string

unlines_gen g concatenates all strings of g, separated with '\n'.

val set : string ‑> int ‑> char ‑> string

set s i c creates a new string which is a copy of s, except for index i, which becomes c.

val iter : (char ‑> unit) ‑> string ‑> unit

Alias to String.iter.

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

Iter on chars with their index.

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

Map chars.

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

Map chars with their index.

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).

val filter : (char ‑> bool) ‑> string ‑> string

filter f s discards characters not satisfying f.

val flat_map : ?⁠sep:string ‑> (char ‑> string) ‑> string ‑> string

Map each chars to a string, then concatenates them all.

val for_all : (char ‑> bool) ‑> string ‑> bool

True for all chars?

val exists : (char ‑> bool) ‑> string ‑> bool

True for some char?

include S with type S.t := string
type t
val length : t ‑> int

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

val blit : t ‑> int ‑> Bytes.t ‑> int ‑> int ‑> unit

Like String.blit. Compatible with the -safe-string option.

  • Raises Invalid_argument: if indices are not valid.
val fold : ('a ‑> char ‑> 'a) ‑> 'a ‑> t ‑> 'a

Fold on chars by increasing index.

  • Since: 0.7

Conversions

val to_gen : t ‑> char gen

Return the gen of characters contained in the string.

val to_seq : t ‑> char sequence

Return the sequence of characters contained in the string.

val to_klist : t ‑> char klist

Return the klist of characters contained in the string.

val to_list : t ‑> char list

Return the list of characters contained in the string.

val pp_buf : Buffer.t ‑> t ‑> unit

Renamed from pp since 2.0.

val pp : Format.formatter ‑> t ‑> unit

Print the string within quotes.

Renamed from print since 2.0.

val ltrim : t ‑> t

Trim space on the left (see String.trim for more details).

val rtrim : t ‑> t

Trim space on the right (see String.trim for more details).

Operations on 2 strings

val map2 : (char ‑> char ‑> char) ‑> string ‑> string ‑> string

Map pairs of chars.

val iter2 : (char ‑> char ‑> unit) ‑> string ‑> string ‑> unit

Iterate on pairs of chars.

val iteri2 : (int ‑> char ‑> char ‑> unit) ‑> string ‑> string ‑> unit

Iterate on pairs of chars with their index.

val fold2 : ('a ‑> char ‑> char ‑> 'a) ‑> 'a ‑> string ‑> string ‑> 'a

Fold on pairs of chars.

val for_all2 : (char ‑> char ‑> bool) ‑> string ‑> string ‑> bool

All pairs of chars respect the predicate?

val exists2 : (char ‑> char ‑> bool) ‑> string ‑> string ‑> bool

Exists a pair of chars?

Ascii functions

Those functions are deprecated in String since 4.03, so we provide a stable alias for them even in older versions.

val capitalize_ascii : string ‑> string

See String.

val uncapitalize_ascii : string ‑> string

See String.

val uppercase_ascii : string ‑> string

See String.

val lowercase_ascii : string ‑> string

See String.

val equal_caseless : string ‑> string ‑> bool

Comparison without respect to ascii lowercase.

Finding

A relatively efficient algorithm for finding sub-strings.

module Find : sig ... end

Splitting

module Split : sig ... end
val split_on_char : char ‑> string ‑> string list

Split the string along the given char.

val split : by:string ‑> string ‑> string list

Alias to Split.list_cpy.

Utils

val compare_versions : string ‑> string ‑> int

compare_versions a b compares version stringsa and b, considering that numbers are above text.

val compare_natural : string ‑> string ‑> int

Natural Sort Order, comparing chunks of digits as natural numbers. https://en.wikipedia.org/wiki/Natural_sort_order

val edit_distance : string ‑> string ‑> int

Edition distance between two strings. This satisfies the classical distance axioms: it is always positive, symmetric, and satisfies the formula distance a b + distance b c >= distance a c.

Slices

A contiguous part of a string

module Sub : sig ... end