Stdlib.StringLabels(3) OCaml library Stdlib.StringLabels(3) NAME Stdlib.StringLabels - no description Module Module Stdlib.StringLabels Documentation Module StringLabels : (module Stdlib__StringLabels) Strings type t = string The type for strings. val make : int -> char -> string make n c is a string of length n with each index holding the character c . Raises Invalid_argument if n < 0 or n > Sys.max_string_length . val init : int -> f:(int -> char) -> string init n ~f is a string of length n with index i holding the character f i (called in increasing index order). Since 4.02 Raises Invalid_argument if n < 0 or n > Sys.max_string_length . val empty : string The empty string. Since 4.13 val length : string -> int length s is the length (number of bytes/characters) of s . val get : string -> int -> char get s i is the character at index i in s . This is the same as writing s.[i] . Raises Invalid_argument if i not an index of s . val of_bytes : bytes -> string Return a new string that contains the same bytes as the given byte sequence. Since 4.13 val to_bytes : string -> bytes Return a new byte sequence that contains the same bytes as the given string. Since 4.13 val blit : src:string -> src_pos:int -> dst:bytes -> dst_pos:int -> len:int -> unit Same as Bytes.blit_string which should be preferred. Concatenating Note. The (^) binary operator concatenates two strings. val concat : sep:string -> string list -> string concat ~sep ss concatenates the list of strings ss , inserting the separator string sep between each. Raises Invalid_argument if the result is longer than Sys.max_string_length bytes. val cat : string -> string -> string cat s1 s2 concatenates s1 and s2 ( s1 ^ s2 ). Since 4.13 Raises Invalid_argument if the result is longer than Sys.max_string_length bytes. Predicates and comparisons val equal : t -> t -> bool equal s0 s1 is true if and only if s0 and s1 are character-wise equal. Since 4.05 val compare : t -> t -> int compare s0 s1 sorts s0 and s1 in lexicographical order. compare behaves like compare on strings but may be more efficient. val starts_with : prefix:string -> string -> bool starts_with ~prefix s is true if and only if s starts with prefix . Since 4.13 val ends_with : suffix:string -> string -> bool ends_with ~suffix s is true if and only if s ends with suffix . Since 4.13 val contains_from : string -> int -> char -> bool contains_from s start c is true if and only if c appears in s after position start . Raises Invalid_argument if start is not a valid position in s . val rcontains_from : string -> int -> char -> bool rcontains_from s stop c is true if and only if 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 contains : string -> char -> bool contains s c is String.contains_from s 0 c . Extracting substrings val sub : string -> pos:int -> len:int -> string sub s ~pos ~len is a string of length len , containing the substring of s that starts at position pos and has length len . Raises Invalid_argument if pos and len do not designate a valid substring of s . val split_on_char : sep:char -> string -> string list split_on_char ~sep s is the list of all (possibly empty) substrings of s that are delimited by the character sep . The function's result 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 ( concat (make 1 sep) (split_on_char sep s) = s ). -No string in the result contains the sep character. Since 4.05 Transforming val map : f:(char -> char) -> string -> string map f s is the string resulting from applying f to all the characters of s in increasing order. Since 4.00 val mapi : f:(int -> char -> char) -> string -> string mapi ~f s is like StringLabels.map but the index of the character is also passed to f . Since 4.02 val fold_left : f:('acc -> char -> 'acc) -> init:'acc -> string -> 'acc fold_left f x s computes f (... (f (f x s.[0]) s.[1]) ...) s.[n-1] , where n is the length of the string s . Since 4.13 val fold_right : f:(char -> 'acc -> 'acc) -> string -> init:'acc -> 'acc fold_right f s x computes f s.[0] (f s.[1] ( ... (f s.[n-1] x) ...)) , where n is the length of the string s . Since 4.13 val for_all : f:(char -> bool) -> string -> bool for_all p s checks if all characters in s satisfy the predicate p . Since 4.13 val exists : f:(char -> bool) -> string -> bool exists p s checks if at least one character of s satisfies the predicate p . Since 4.13 val trim : string -> string trim s is s without leading and trailing whitespace. Whitespace characters are: ' ' , '\x0C' (form feed), '\n' , '\r' , and '\t' . Since 4.00 val escaped : string -> string escaped s is s with special characters represented by escape sequences, following the lexical conventions of OCaml. All characters outside the US-ASCII printable range [0x20;0x7E] are escaped, as well as backslash (0x2F) and double-quote (0x22). The function Scanf.unescaped is a left inverse of escaped , i.e. Scanf.unescaped (escaped s) = s for any string s (unless escaped s fails). Raises Invalid_argument if the result is longer than Sys.max_string_length bytes. val uppercase_ascii : string -> string uppercase_ascii s is s with all lowercase letters translated to uppercase, using the US-ASCII character set. Since 4.05 val lowercase_ascii : string -> string lowercase_ascii s is s with all uppercase letters translated to lowercase, using the US-ASCII character set. Since 4.05 val capitalize_ascii : string -> string capitalize_ascii s is s with the first character set to uppercase, using the US-ASCII character set. Since 4.05 val uncapitalize_ascii : string -> string uncapitalize_ascii s is s with the first character set to lowercase, using the US-ASCII character set. Since 4.05 Traversing val iter : f:(char -> unit) -> string -> unit 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.[length s - 1]; () . val iteri : f:(int -> char -> unit) -> string -> unit iteri is like StringLabels.iter , but the function is also given the corresponding character index. Since 4.00 Searching val index_from : string -> int -> char -> int index_from s i c is the index of the first occurrence of c in s after position i . Raises Not_found if c does not occur in s after position i . Raises Invalid_argument if i is not a valid position in s . val index_from_opt : string -> int -> char -> int option index_from_opt s i c is the index of the first occurrence of c in s after position i (if any). Since 4.05 Raises Invalid_argument if i is not a valid position in s . val rindex_from : string -> int -> char -> int rindex_from s i c is the index of the last occurrence of c in s before position i+1 . Raises Not_found if c does not occur in s before position i+1 . Raises Invalid_argument if i+1 is not a valid position in s . val rindex_from_opt : string -> int -> char -> int option rindex_from_opt s i c is the index of the last occurrence of c in s before position i+1 (if any). Since 4.05 Raises Invalid_argument if i+1 is not a valid position in s . val index : string -> char -> int index s c is String.index_from s 0 c . val index_opt : string -> char -> int option index_opt s c is String.index_from_opt s 0 c . Since 4.05 val rindex : string -> char -> int rindex s c is String.rindex_from s (length s - 1) c . val rindex_opt : string -> char -> int option rindex_opt s c is String.rindex_from_opt s (length s - 1) c . Since 4.05 Strings and Sequences val to_seq : t -> char Seq.t to_seq s is a sequence made of the string's characters in increasing order. In "unsafe-string" mode, modifications of the string during iteration will be reflected in the sequence. Since 4.07 val to_seqi : t -> (int * char) Seq.t to_seqi s is like StringLabels.to_seq but also tuples the corresponding index. Since 4.07 val of_seq : char Seq.t -> t of_seq s is a string made of the sequence's characters. Since 4.07 UTF decoding and validations UTF-8 val get_utf_8_uchar : t -> int -> Uchar.utf_decode get_utf_8_uchar b i decodes an UTF-8 character at index i in b . val is_valid_utf_8 : t -> bool is_valid_utf_8 b is true if and only if b contains valid UTF-8 data. UTF-16BE val get_utf_16be_uchar : t -> int -> Uchar.utf_decode get_utf_16be_uchar b i decodes an UTF-16BE character at index i in b . val is_valid_utf_16be : t -> bool is_valid_utf_16be b is true if and only if b contains valid UTF-16BE data. UTF-16LE val get_utf_16le_uchar : t -> int -> Uchar.utf_decode get_utf_16le_uchar b i decodes an UTF-16LE character at index i in b . val is_valid_utf_16le : t -> bool is_valid_utf_16le b is true if and only if b contains valid UTF-16LE data. Binary decoding of integers The functions in this section binary decode integers from strings. All following functions raise Invalid_argument if the characters needed at index i to decode the integer are not available. Little-endian (resp. big-endian) encoding means that least (resp. most) significant bytes are stored first. Big-endian is also known as network byte order. Native-endian encoding is either little-endian or big-endian depending on Sys.big_endian . 32-bit and 64-bit integers are represented by the int32 and int64 types, which can be interpreted either as signed or unsigned numbers. 8-bit and 16-bit integers are represented by the int type, which has more bits than the binary encoding. These extra bits are sign-extended (or zero-extended) for functions which decode 8-bit or 16-bit integers and represented them with int values. val get_uint8 : string -> int -> int get_uint8 b i is b 's unsigned 8-bit integer starting at character index i . Since 4.13 val get_int8 : string -> int -> int get_int8 b i is b 's signed 8-bit integer starting at character index i . Since 4.13 val get_uint16_ne : string -> int -> int get_uint16_ne b i is b 's native-endian unsigned 16-bit integer starting at character index i . Since 4.13 val get_uint16_be : string -> int -> int get_uint16_be b i is b 's big-endian unsigned 16-bit integer starting at character index i . Since 4.13 val get_uint16_le : string -> int -> int get_uint16_le b i is b 's little-endian unsigned 16-bit integer starting at character index i . Since 4.13 val get_int16_ne : string -> int -> int get_int16_ne b i is b 's native-endian signed 16-bit integer starting at character index i . Since 4.13 val get_int16_be : string -> int -> int get_int16_be b i is b 's big-endian signed 16-bit integer starting at character index i . Since 4.13 val get_int16_le : string -> int -> int get_int16_le b i is b 's little-endian signed 16-bit integer starting at character index i . Since 4.13 val get_int32_ne : string -> int -> int32 get_int32_ne b i is b 's native-endian 32-bit integer starting at character index i . Since 4.13 val hash : t -> int An unseeded hash function for strings, with the same output value as Hashtbl.hash . This function allows this module to be passed as argument to the functor Hashtbl.Make . Since 5.0 val seeded_hash : int -> t -> int A seeded hash function for strings, with the same output value as Hashtbl.seeded_hash . This function allows this module to be passed as argument to the functor Hashtbl.MakeSeeded . Since 5.0 val get_int32_be : string -> int -> int32 get_int32_be b i is b 's big-endian 32-bit integer starting at character index i . Since 4.13 val get_int32_le : string -> int -> int32 get_int32_le b i is b 's little-endian 32-bit integer starting at character index i . Since 4.13 val get_int64_ne : string -> int -> int64 get_int64_ne b i is b 's native-endian 64-bit integer starting at character index i . Since 4.13 val get_int64_be : string -> int -> int64 get_int64_be b i is b 's big-endian 64-bit integer starting at character index i . Since 4.13 val get_int64_le : string -> int -> int64 get_int64_le b i is b 's little-endian 64-bit integer starting at character index i . Since 4.13 OCamldoc 2024-02-29 Stdlib.StringLabels(3)