package containers

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package containers
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Basic String Utils

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 struct include Stdlib.StringLabels end
type t = string
val make : int -> char -> string
val empty : string
val of_bytes : bytes -> string
val to_bytes : string -> bytes
val get : string -> int -> char
val concat : sep:string -> string list -> string
val cat : string -> string -> string
val starts_with : prefix:string -> string -> bool
val ends_with : suffix:string -> string -> bool
val contains_from : string -> int -> char -> bool
val rcontains_from : string -> int -> char -> bool
val contains : string -> char -> bool
val sub : string -> pos:int -> len:int -> string
val fold_left : f:('a -> char -> 'a) -> init:'a -> string -> 'a
val fold_right : f:(char -> 'a -> 'a) -> string -> init:'a -> 'a
val trim : string -> string
val escaped : string -> string
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 index : string -> char -> int
val index_opt : string -> char -> int option
val rindex : string -> char -> int
val rindex_opt : string -> char -> int option
val to_seqi : t -> (int * char) Stdlib.Seq.t
val create : int -> bytes
  • deprecated Use Bytes.create/BytesLabels.create instead.
val copy : string -> string
  • deprecated Strings now immutable: no need to copy
val fill : bytes -> pos:int -> len:int -> char -> unit
  • deprecated Use Bytes.fill/BytesLabels.fill instead.
val uppercase : string -> string
  • deprecated Use String.uppercase_ascii/StringLabels.uppercase_ascii instead.
val lowercase : string -> string
  • deprecated Use String.lowercase_ascii/StringLabels.lowercase_ascii instead.
val capitalize : string -> string
  • deprecated Use String.capitalize_ascii/StringLabels.capitalize_ascii instead.
val uncapitalize : string -> string
  • deprecated Use String.uncapitalize_ascii/StringLabels.uncapitalize_ascii instead.
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 unsafe_get : string -> int -> char
val unsafe_set : bytes -> int -> char -> unit
  • deprecated
val unsafe_blit : src:string -> src_pos:int -> dst:bytes -> dst_pos:int -> len:int -> unit
val unsafe_fill : bytes -> pos:int -> len:int -> char -> unit
  • deprecated
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).

  • since 1.5
val hash : string -> int
val init : int -> (int -> char) -> string

Like Array.init.

  • since 0.3.3
val rev : string -> string

rev s returns the reverse of s.

  • since 0.17
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.

  • parameter side

    determines where padding occurs (default: `Left).

  • parameter c

    the char used to pad (default: ' ').

  • since 0.17
val of_char : char -> string

of_char 'a' is "a".

  • since 0.19
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.

  • parameter start

    starting position in s.

  • since 0.17
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.

  • parameter start

    starting position in s.

  • since 0.17
val mem : ?start:int -> sub:string -> string -> bool

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

  • since 0.12
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.

  • since 0.12
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.

  • parameter which

    decides whether the occurrences to replace are:

    • `Left first occurrence from the left (beginning).
    • `Right first occurrence from the right (end).
    • `All all occurrences (default).
  • raises Invalid_argument

    if sub = "".

  • since 0.14
val is_sub : sub:string -> sub_pos:int -> string -> pos:int -> sub_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.

  • since 0.7
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.

  • since 0.17
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.

  • since 0.17
val take : int -> string -> string

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

  • since 0.17
val drop : int -> string -> string

drop n s removes the n first chars of s.

  • since 0.17
val take_drop : int -> string -> string * string

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

  • since 0.17
val lines : string -> string list

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

  • since 0.10
val lines_gen : string -> string gen

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

  • since 0.10
val concat_gen : sep:string -> string gen -> string

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

  • since 0.10
val unlines : string list -> string

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

  • since 0.10
val unlines_gen : string gen -> string

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

  • since 0.10
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.

  • raises Invalid_argument

    if i is an invalid index.

  • since 0.12
val iter : f:(char -> unit) -> string -> unit

Alias to String.iter.

  • since 0.12
val iteri : f:(int -> char -> unit) -> string -> unit

Iter on chars with their index.

  • since 0.12
val map : f:(char -> char) -> string -> string

Map chars.

  • since 0.12
val mapi : f:(int -> char -> char) -> string -> string

Map chars with their index.

  • since 0.12
val filter_map : f:(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).

  • since 0.17
val filter : f:(char -> bool) -> string -> string

filter f s discards characters not satisfying f.

  • since 0.17
val flat_map : ?sep:string -> f:(char -> string) -> string -> string

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

  • parameter sep

    optional separator between each generated string.

  • since 0.12
val for_all : f:(char -> bool) -> string -> bool

True for all chars?

  • since 0.12
val exists : f:(char -> bool) -> string -> bool

True for some char?

  • since 0.12
include S with type t := string
val length : string -> int

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

val blit : src:string -> src_pos:int -> dst:Stdlib.Bytes.t -> dst_pos:int -> len:int -> unit

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

  • raises Invalid_argument

    if indices are not valid.

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

Fold on chars by increasing index.

  • since 0.7

Conversions

val to_gen : string -> char gen

Return the gen of characters contained in the string.

val to_seq : string -> char sequence

Return the sequence of characters contained in the string.

val to_klist : string -> char klist

Return the klist of characters contained in the string.

val to_list : string -> char list

Return the list of characters contained in the string.

val pp_buf : Stdlib.Buffer.t -> string -> unit

Renamed from pp since 2.0.

val pp : Stdlib.Format.formatter -> string -> unit

Print the string within quotes.

Renamed from print since 2.0.

val drop_while : f:(char -> bool) -> t -> t

drop_while f s discards any characters starting from the left, up to the first character c not satisfying f c.

  • since 2.2
val rdrop_while : f:(char -> bool) -> t -> t

rdrop_while f s discards any characters starting from the right, up to the first character c not satisfying f c.

  • since 2.2
val ltrim : t -> t

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

  • since 1.2
val rtrim : t -> t

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

  • since 1.2

Operations on 2 strings

val map2 : f:(char -> char -> char) -> string -> string -> string

Map pairs of chars.

  • raises Invalid_argument

    if the strings have not the same length.

  • since 0.12
val iter2 : f:(char -> char -> unit) -> string -> string -> unit

Iterate on pairs of chars.

  • raises Invalid_argument

    if the strings have not the same length.

  • since 0.12
val iteri2 : f:(int -> char -> char -> unit) -> string -> string -> unit

Iterate on pairs of chars with their index.

  • raises Invalid_argument

    if the strings have not the same length.

  • since 0.12
val fold2 : f:('a -> char -> char -> 'a) -> init:'a -> string -> string -> 'a

Fold on pairs of chars.

  • raises Invalid_argument

    if the strings have not the same length.

  • since 0.12
val for_all2 : f:(char -> char -> bool) -> string -> string -> bool

All pairs of chars respect the predicate?

  • raises Invalid_argument

    if the strings have not the same length.

  • since 0.12
val exists2 : f:(char -> char -> bool) -> string -> string -> bool

Exists a pair of chars?

  • raises Invalid_argument

    if the strings have not the same length.

  • since 0.12

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.

  • since 0.18
val uncapitalize_ascii : string -> string

See String.

  • since 0.18
val uppercase_ascii : string -> string

See String.

  • since 0.18
val lowercase_ascii : string -> string

See String.

  • since 0.18
val equal_caseless : string -> string -> bool

Comparison without respect to ascii lowercase.

  • since 1.2

Finding

A relatively efficient algorithm for finding sub-strings.

  • since 1.0
module Find : sig ... end

Splitting

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

Split the string along the given char.

  • since 1.2
val split : by:string -> string -> string list

Alias to Split.list_cpy.

  • since 1.2

Utils

val compare_versions : string -> string -> int

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

  • since 0.13
val compare_natural : string -> string -> int

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

  • since 1.3
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
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