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 Deprecated functions
530 val create : int -> bytes
531 Deprecated. This is a deprecated alias of Bytes.create / BytesLa‐
533 bels.create .
534 create n returns a fresh byte sequence of length n . The sequence is
538 uninitialized and contains arbitrary bytes.
539 Raises Invalid_argument if n < 0 or n > Sys.max_string_length .
542 val set : bytes -> int -> char -> unit
546 Deprecated. This is a deprecated alias of Bytes.set / BytesLabels.set
548 .
549 set s n c modifies byte sequence s in place, replacing the byte at in‐
553 dex n with c . You can also write s.[n] <- c instead of set s n c .
554 Raises Invalid_argument if n is not a valid index in s .
557 val blit : src:string -> src_pos:int -> dst:bytes -> dst_pos:int ->
561 len:int -> unit
562 blit ~src ~src_pos ~dst ~dst_pos ~len copies len bytes from the string
565 src , starting at index src_pos , to byte sequence dst , starting at
566 character number dst_pos .
567 Raises Invalid_argument if src_pos and len do not designate a valid
570 range of src , or if dst_pos and len do not designate a valid range of
571 dst .
572 val copy : string -> string
576 Deprecated. Because strings are immutable, it doesn't make much sense
578 to make identical copies of them.
579 Return a copy of the given string.
582 val fill : bytes -> pos:int -> len:int -> char -> unit
586 Deprecated. This is a deprecated alias of Bytes.fill / BytesLa‐
588 bels.fill .
589 fill s ~pos ~len c modifies byte sequence s in place, replacing len
593 bytes by c , starting at pos .
594 Raises Invalid_argument if pos and len do not designate a valid sub‐
597 string of s .
598 val uppercase : string -> string
602 Deprecated. Functions operating on Latin-1 character set are depre‐
604 cated.
605 Return a copy of the argument, with all lowercase letters translated to
608 uppercase, including accented letters of the ISO Latin-1 (8859-1) char‐
609 acter set.
610 val lowercase : string -> string
614 Deprecated. Functions operating on Latin-1 character set are depre‐
616 cated.
617 Return a copy of the argument, with all uppercase letters translated to
620 lowercase, including accented letters of the ISO Latin-1 (8859-1) char‐
621 acter set.
622 val capitalize : string -> string
626 Deprecated. Functions operating on Latin-1 character set are depre‐
628 cated.
629 Return a copy of the argument, with the first character set to upper‐
632 case, using the ISO Latin-1 (8859-1) character set..
633 val uncapitalize : string -> string
637 Deprecated. Functions operating on Latin-1 character set are depre‐
639 cated.
640 Return a copy of the argument, with the first character set to lower‐
643 case, using the ISO Latin-1 (8859-1) character set.
644 Binary decoding of integers
649 The functions in this section binary decode integers from strings.
650 All following functions raise Invalid_argument if the characters needed
652 at index i to decode the integer are not available.
653 Little-endian (resp. big-endian) encoding means that least (resp. most)
655 significant bytes are stored first. Big-endian is also known as net‐
656 work byte order. Native-endian encoding is either little-endian or
657 big-endian depending on Sys.big_endian .
658 32-bit and 64-bit integers are represented by the int32 and int64
660 types, which can be interpreted either as signed or unsigned numbers.
661 8-bit and 16-bit integers are represented by the int type, which has
663 more bits than the binary encoding. These extra bits are sign-extended
664 (or zero-extended) for functions which decode 8-bit or 16-bit integers
665 and represented them with int values.
666 val get_uint8 : string -> int -> int
668 get_uint8 b i is b 's unsigned 8-bit integer starting at character in‐
671 dex i .
672 Since 4.13.0
675 val get_int8 : string -> int -> int
679 get_int8 b i is b 's signed 8-bit integer starting at character index i
682 .
683 Since 4.13.0
686 val get_uint16_ne : string -> int -> int
690 get_uint16_ne b i is b 's native-endian unsigned 16-bit integer start‐
693 ing at character index i .
694 Since 4.13.0
697 val get_uint16_be : string -> int -> int
701 get_uint16_be b i is b 's big-endian unsigned 16-bit integer starting
704 at character index i .
705 Since 4.13.0
708 val get_uint16_le : string -> int -> int
712 get_uint16_le b i is b 's little-endian unsigned 16-bit integer start‐
715 ing at character index i .
716 Since 4.13.0
719 val get_int16_ne : string -> int -> int
723 get_int16_ne b i is b 's native-endian signed 16-bit integer starting
726 at character index i .
727 Since 4.13.0
730 val get_int16_be : string -> int -> int
734 get_int16_be b i is b 's big-endian signed 16-bit integer starting at
737 character index i .
738 Since 4.13.0
741 val get_int16_le : string -> int -> int
745 get_int16_le b i is b 's little-endian signed 16-bit integer starting
748 at character index i .
749 Since 4.13.0
752 val get_int32_ne : string -> int -> int32
756 get_int32_ne b i is b 's native-endian 32-bit integer starting at char‐
759 acter index i .
760 Since 4.13.0
763 val get_int32_be : string -> int -> int32
767 get_int32_be b i is b 's big-endian 32-bit integer starting at charac‐
770 ter index i .
771 Since 4.13.0
774 val get_int32_le : string -> int -> int32
778 get_int32_le b i is b 's little-endian 32-bit integer starting at char‐
781 acter index i .
782 Since 4.13.0
785 val get_int64_ne : string -> int -> int64
789 get_int64_ne b i is b 's native-endian 64-bit integer starting at char‐
792 acter index i .
793 Since 4.13.0
796 val get_int64_be : string -> int -> int64
800 get_int64_be b i is b 's big-endian 64-bit integer starting at charac‐
803 ter index i .
804 Since 4.13.0
807 val get_int64_le : string -> int -> int64
811 get_int64_le b i is b 's little-endian 64-bit integer starting at char‐
814 acter index i .
815 Since 4.13.0
818OCamldoc 2022-02-04 Stdlib.StringLabels(3)