1Stdlib.StringLabels(3) OCaml library Stdlib.StringLabels(3)
2
6 Stdlib.StringLabels - no description
7
9 Module Stdlib.StringLabels
10
12 Module StringLabels
13 : (module Stdlib__StringLabels)
14 Strings
24 type t = string
25 The type for strings.
28 val make : int -> char -> string
32 make n c is a string of length n with each index holding the character
35 c .
36 Raises Invalid_argument if n < 0 or n > Sys.max_string_length .
39 val init : int -> f:(int -> char) -> string
43 init n ~f is a string of length n with index i holding the character f
46 i (called in increasing index order).
47 Since 4.02.0
50 Raises Invalid_argument if n < 0 or n > Sys.max_string_length .
53 val empty : string
57 The empty string.
59 Since 4.13.0
62 val of_bytes : bytes -> string
66 Return a new string that contains the same bytes as the given byte se‐
68 quence.
69 Since 4.13.0
72 val to_bytes : string -> bytes
76 Return a new byte sequence that contains the same bytes as the given
78 string.
79 Since 4.13.0
82 val length : string -> int
86 length s is the length (number of bytes/characters) of s .
89 val get : string -> int -> char
93 get s i is the character at index i in s . This is the same as writing
96 s.[i] .
97 Raises Invalid_argument if i not an index of s .
100 Concatenating
105 Note. The (^) binary operator concatenates two strings.
106 val concat : sep:string -> string list -> string
108 concat ~sep ss concatenates the list of strings ss , inserting the sep‐
111 arator string sep between each.
112 Raises Invalid_argument if the result is longer than
115 Sys.max_string_length bytes.
116 val cat : string -> string -> string
120 cat s1 s2 concatenates s1 and s2 ( s1 ^ s2 ).
123 Since 4.13.0
126 Raises Invalid_argument if the result is longer then than
129 Sys.max_string_length bytes.
130 Predicates and comparisons
135 val equal : t -> t -> bool
136 equal s0 s1 is true if and only if s0 and s1 are character-wise equal.
139 Since 4.05.0
142 val compare : t -> t -> int
146 compare s0 s1 sorts s0 and s1 in lexicographical order. compare be‐
149 haves like compare on strings but may be more efficient.
150 val starts_with : prefix:string -> string -> bool
154 starts_with ~ prefix s is true if and only if s starts with prefix .
157 Since 4.13.0
160 val ends_with : suffix:string -> string -> bool
164 ends_with ~suffix s is true if and only if s ends with suffix .
167 Since 4.13.0
170 val contains_from : string -> int -> char -> bool
174 contains_from s start c is true if and only if c appears in s after po‐
177 sition start .
178 Raises Invalid_argument if start is not a valid position in s .
181 val rcontains_from : string -> int -> char -> bool
185 rcontains_from s stop c is true if and only if c appears in s before
188 position stop+1 .
189 Raises Invalid_argument if stop < 0 or stop+1 is not a valid position
192 in s .
193 val contains : string -> char -> bool
197 contains s c is String.contains_from s 0 c .
200 Extracting substrings
205 val sub : string -> pos:int -> len:int -> string
206 sub s ~pos ~len is a string of length len , containing the substring of
209 s that starts at position pos and has length len .
210 Raises Invalid_argument if pos and len do not designate a valid sub‐
213 string of s .
214 val split_on_char : sep:char -> string -> string list
218 split_on_char ~sep s is the list of all (possibly empty) substrings of
221 s that are delimited by the character sep .
222 The function's result is specified by the following invariants:
224 -The list is not empty.
226 -Concatenating its elements using sep as a separator returns a string
228 equal to the input ( concat (make 1 sep)
229 (split_on_char sep s) = s ).
230 -No string in the result contains the sep character.
232 Since 4.05.0
236 Transforming
241 val map : f:(char -> char) -> string -> string
242 map f s is the string resulting from applying f to all the characters
245 of s in increasing order.
246 Since 4.00.0
249 val mapi : f:(int -> char -> char) -> string -> string
253 mapi ~f s is like StringLabels.map but the index of the character is
256 also passed to f .
257 Since 4.02.0
260 val fold_left : f:('a -> char -> 'a) -> init:'a -> string -> 'a
264 fold_left f x s computes f (... (f (f x s.[0]) s.[1]) ...) s.[n-1] ,
267 where n is the length of the string s .
268 Since 4.13.0
271 val fold_right : f:(char -> 'a -> 'a) -> string -> init:'a -> 'a
275 fold_right f s x computes f s.[0] (f s.[1] ( ... (f s.[n-1] x) ...)) ,
278 where n is the length of the string s .
279 Since 4.13.0
282 val for_all : f:(char -> bool) -> string -> bool
286 for_all p s checks if all characters in s satisfy the predicate p .
289 Since 4.13.0
292 val exists : f:(char -> bool) -> string -> bool
296 exists p s checks if at least one character of s satisfies the predi‐
299 cate p .
300 Since 4.13.0
303 val trim : string -> string
307 trim s is s without leading and trailing whitespace. Whitespace charac‐
310 ters are: ' ' , '\x0C' (form feed), '\n' , '\r' , and '\t' .
311 Since 4.00.0
314 val escaped : string -> string
318 escaped s is s with special characters represented by escape sequences,
321 following the lexical conventions of OCaml.
322 All characters outside the US-ASCII printable range [0x20;0x7E] are es‐
324 caped, as well as backslash (0x2F) and double-quote (0x22).
325 The function Scanf.unescaped is a left inverse of escaped , i.e.
327 Scanf.unescaped (escaped s) = s for any string s (unless escaped s
328 fails).
329 Raises Invalid_argument if the result is longer than
332 Sys.max_string_length bytes.
333 val uppercase_ascii : string -> string
337 uppercase_ascii s is s with all lowercase letters translated to upper‐
340 case, using the US-ASCII character set.
341 Since 4.05.0
344 val lowercase_ascii : string -> string
348 lowercase_ascii s is s with all uppercase letters translated to lower‐
351 case, using the US-ASCII character set.
352 Since 4.05.0
355 val capitalize_ascii : string -> string
359 capitalize_ascii s is s with the first character set to uppercase, us‐
362 ing the US-ASCII character set.
363 Since 4.05.0
366 val uncapitalize_ascii : string -> string
370 uncapitalize_ascii s is s with the first character set to lowercase,
373 using the US-ASCII character set.
374 Since 4.05.0
377 Traversing
382 val iter : f:(char -> unit) -> string -> unit
383 iter ~f s applies function f in turn to all the characters of s . It
386 is equivalent to f s.[0]; f s.[1]; ...; f s.[length s - 1]; () .
387 val iteri : f:(int -> char -> unit) -> string -> unit
391 iteri is like StringLabels.iter , but the function is also given the
394 corresponding character index.
395 Since 4.00.0
398 Searching
403 val index_from : string -> int -> char -> int
404 index_from s i c is the index of the first occurrence of c in s after
407 position i .
408 Raises Not_found if c does not occur in s after position i .
411 Raises Invalid_argument if i is not a valid position in s .
414 val index_from_opt : string -> int -> char -> int option
418 index_from_opt s i c is the index of the first occurrence of c in s af‐
421 ter position i (if any).
422 Since 4.05
425 Raises Invalid_argument if i is not a valid position in s .
428 val rindex_from : string -> int -> char -> int
432 rindex_from s i c is the index of the last occurrence of c in s before
435 position i+1 .
436 Raises Not_found if c does not occur in s before position i+1 .
439 Raises Invalid_argument if i+1 is not a valid position in s .
442 val rindex_from_opt : string -> int -> char -> int option
446 rindex_from_opt s i c is the index of the last occurrence of c in s be‐
449 fore position i+1 (if any).
450 Since 4.05
453 Raises Invalid_argument if i+1 is not a valid position in s .
456 val index : string -> char -> int
460 index s c is String.index_from s 0 c .
463 val index_opt : string -> char -> int option
467 index_opt s c is String.index_from_opt s 0 c .
470 Since 4.05
473 val rindex : string -> char -> int
477 rindex s c is String.rindex_from s (length s - 1) c .
480 val rindex_opt : string -> char -> int option
484 rindex_opt s c is String.rindex_from_opt s (length s - 1) c .
487 Since 4.05
490 Strings and Sequences
495 val to_seq : t -> char Seq.t
496 to_seq s is a sequence made of the string's characters in increasing
499 order. In "unsafe-string" mode, modifications of the string during it‐
500 eration will be reflected in the sequence.
501 Since 4.07
504 val to_seqi : t -> (int * char) Seq.t
508 to_seqi s is like StringLabels.to_seq but also tuples the corresponding
511 index.
512 Since 4.07
515 val of_seq : char Seq.t -> t
519 of_seq s is a string made of the sequence's characters.
522 Since 4.07
525 UTF decoding and validations
530 UTF-8
531 val get_utf_8_uchar : t -> int -> Uchar.utf_decode
532 get_utf_8_uchar b i decodes an UTF-8 character at index i in b .
535 val is_valid_utf_8 : t -> bool
539 is_valid_utf_8 b is true if and only if b contains valid UTF-8 data.
542 UTF-16BE
547 val get_utf_16be_uchar : t -> int -> Uchar.utf_decode
548 get_utf_16be_uchar b i decodes an UTF-16BE character at index i in b .
551 val is_valid_utf_16be : t -> bool
555 is_valid_utf_16be b is true if and only if b contains valid UTF-16BE
558 data.
559 UTF-16LE
564 val get_utf_16le_uchar : t -> int -> Uchar.utf_decode
565 get_utf_16le_uchar b i decodes an UTF-16LE character at index i in b .
568 val is_valid_utf_16le : t -> bool
572 is_valid_utf_16le b is true if and only if b contains valid UTF-16LE
575 data.
576 Deprecated functions
581 val create : int -> bytes
582 Deprecated. This is a deprecated alias of Bytes.create / BytesLa‐
584 bels.create .
585 create n returns a fresh byte sequence of length n . The sequence is
589 uninitialized and contains arbitrary bytes.
590 Raises Invalid_argument if n < 0 or n > Sys.max_string_length .
593 val set : bytes -> int -> char -> unit
597 Deprecated. This is a deprecated alias of Bytes.set / BytesLabels.set
599 .
600 set s n c modifies byte sequence s in place, replacing the byte at in‐
604 dex n with c . You can also write s.[n] <- c instead of set s n c .
605 Raises Invalid_argument if n is not a valid index in s .
608 val blit : src:string -> src_pos:int -> dst:bytes -> dst_pos:int ->
612 len:int -> unit
613 blit ~src ~src_pos ~dst ~dst_pos ~len copies len bytes from the string
616 src , starting at index src_pos , to byte sequence dst , starting at
617 character number dst_pos .
618 Raises Invalid_argument if src_pos and len do not designate a valid
621 range of src , or if dst_pos and len do not designate a valid range of
622 dst .
623 val copy : string -> string
627 Deprecated. Because strings are immutable, it doesn't make much sense
629 to make identical copies of them.
630 Return a copy of the given string.
633 val fill : bytes -> pos:int -> len:int -> char -> unit
637 Deprecated. This is a deprecated alias of Bytes.fill / BytesLa‐
639 bels.fill .
640 fill s ~pos ~len c modifies byte sequence s in place, replacing len
644 bytes by c , starting at pos .
645 Raises Invalid_argument if pos and len do not designate a valid sub‐
648 string of s .
649 val uppercase : string -> string
653 Deprecated. Functions operating on Latin-1 character set are depre‐
655 cated.
656 Return a copy of the argument, with all lowercase letters translated to
659 uppercase, including accented letters of the ISO Latin-1 (8859-1) char‐
660 acter set.
661 val lowercase : string -> string
665 Deprecated. Functions operating on Latin-1 character set are depre‐
667 cated.
668 Return a copy of the argument, with all uppercase letters translated to
671 lowercase, including accented letters of the ISO Latin-1 (8859-1) char‐
672 acter set.
673 val capitalize : string -> string
677 Deprecated. Functions operating on Latin-1 character set are depre‐
679 cated.
680 Return a copy of the argument, with the first character set to upper‐
683 case, using the ISO Latin-1 (8859-1) character set..
684 val uncapitalize : string -> string
688 Deprecated. Functions operating on Latin-1 character set are depre‐
690 cated.
691 Return a copy of the argument, with the first character set to lower‐
694 case, using the ISO Latin-1 (8859-1) character set.
695 Binary decoding of integers
700 The functions in this section binary decode integers from strings.
701 All following functions raise Invalid_argument if the characters needed
703 at index i to decode the integer are not available.
704 Little-endian (resp. big-endian) encoding means that least (resp. most)
706 significant bytes are stored first. Big-endian is also known as net‐
707 work byte order. Native-endian encoding is either little-endian or
708 big-endian depending on Sys.big_endian .
709 32-bit and 64-bit integers are represented by the int32 and int64
711 types, which can be interpreted either as signed or unsigned numbers.
712 8-bit and 16-bit integers are represented by the int type, which has
714 more bits than the binary encoding. These extra bits are sign-extended
715 (or zero-extended) for functions which decode 8-bit or 16-bit integers
716 and represented them with int values.
717 val get_uint8 : string -> int -> int
719 get_uint8 b i is b 's unsigned 8-bit integer starting at character in‐
722 dex i .
723 Since 4.13.0
726 val get_int8 : string -> int -> int
730 get_int8 b i is b 's signed 8-bit integer starting at character index i
733 .
734 Since 4.13.0
737 val get_uint16_ne : string -> int -> int
741 get_uint16_ne b i is b 's native-endian unsigned 16-bit integer start‐
744 ing at character index i .
745 Since 4.13.0
748 val get_uint16_be : string -> int -> int
752 get_uint16_be b i is b 's big-endian unsigned 16-bit integer starting
755 at character index i .
756 Since 4.13.0
759 val get_uint16_le : string -> int -> int
763 get_uint16_le b i is b 's little-endian unsigned 16-bit integer start‐
766 ing at character index i .
767 Since 4.13.0
770 val get_int16_ne : string -> int -> int
774 get_int16_ne b i is b 's native-endian signed 16-bit integer starting
777 at character index i .
778 Since 4.13.0
781 val get_int16_be : string -> int -> int
785 get_int16_be b i is b 's big-endian signed 16-bit integer starting at
788 character index i .
789 Since 4.13.0
792 val get_int16_le : string -> int -> int
796 get_int16_le b i is b 's little-endian signed 16-bit integer starting
799 at character index i .
800 Since 4.13.0
803 val get_int32_ne : string -> int -> int32
807 get_int32_ne b i is b 's native-endian 32-bit integer starting at char‐
810 acter index i .
811 Since 4.13.0
814 val get_int32_be : string -> int -> int32
818 get_int32_be b i is b 's big-endian 32-bit integer starting at charac‐
821 ter index i .
822 Since 4.13.0
825 val get_int32_le : string -> int -> int32
829 get_int32_le b i is b 's little-endian 32-bit integer starting at char‐
832 acter index i .
833 Since 4.13.0
836 val get_int64_ne : string -> int -> int64
840 get_int64_ne b i is b 's native-endian 64-bit integer starting at char‐
843 acter index i .
844 Since 4.13.0
847 val get_int64_be : string -> int -> int64
851 get_int64_be b i is b 's big-endian 64-bit integer starting at charac‐
854 ter index i .
855 Since 4.13.0
858 val get_int64_le : string -> int -> int64
862 get_int64_le b i is b 's little-endian 64-bit integer starting at char‐
865 acter index i .
866 Since 4.13.0
869OCamldoc 2022-07-22 Stdlib.StringLabels(3)