1StringLabels(3) OCamldoc StringLabels(3)
2
6 StringLabels - String operations.
7
9 Module StringLabels
10
12 Module StringLabels
13 : sig end
14 String operations.
17 val length : string -> int
24 Return the length (number of characters) of the given string.
26 val get : string -> int -> char
30 String.get s n returns the character at index n in string s . You can
33 also write s.[n] instead of String.get s n .
34 Raise Invalid_argument if n not a valid index in s .
36 val set : bytes -> int -> char -> unit
40 Deprecated. This is a deprecated alias of BytesLabels.set .
42 String.set s n c modifies byte sequence s in place, replacing the byte
46 at index n with c . You can also write s.[n] <- c instead of
47 String.set s n c .
48 Raise Invalid_argument if n is not a valid index in s .
50 val create : int -> bytes
54 Deprecated. This is a deprecated alias of BytesLabels.create .
56 String.create n returns a fresh byte sequence of length n . The
60 sequence is uninitialized and contains arbitrary bytes.
61 Raise Invalid_argument if n < 0 or n > Sys.max_string_length .
63 val make : int -> char -> string
67 String.make n c returns a fresh string of length n , filled with the
70 character c .
71 Raise Invalid_argument if n < 0 or n > Sys.max_string_length .
73 val init : int -> f:(int -> char) -> string
77 init n f returns a string of length n , with character i initialized to
80 the result of f i .
81 Raise Invalid_argument if n < 0 or n > Sys.max_string_length .
83 Since 4.02.0
86 val copy : string -> string
90 Return a copy of the given string.
92 val sub : string -> pos:int -> len:int -> string
96 String.sub s start len returns a fresh string of length len , contain‐
99 ing the substring of s that starts at position start and has length len
100 .
101 Raise Invalid_argument if start and len do not designate a valid sub‐
103 string of s .
104 val fill : bytes -> pos:int -> len:int -> char -> unit
108 Deprecated. This is a deprecated alias of BytesLabels.fill .
110 String.fill s start len c modifies byte sequence s in place, replacing
114 len bytes by c , starting at start .
115 Raise Invalid_argument if start and len do not designate a valid sub‐
117 string of s .
118 val blit : src:string -> src_pos:int -> dst:bytes -> dst_pos:int ->
122 len:int -> unit
123 String.blit src srcoff dst dstoff len copies len bytes from the string
126 src , starting at index srcoff , to byte sequence dst , starting at
127 character number dstoff .
128 Raise Invalid_argument if srcoff and len do not designate a valid range
130 of src , or if dstoff and len do not designate a valid range of dst .
131 val concat : sep:string -> string list -> string
135 String.concat sep sl concatenates the list of strings sl , inserting
138 the separator string sep between each.
139 val iter : f:(char -> unit) -> string -> unit
143 String.iter f s applies function f in turn to all the characters of s .
146 It is equivalent to f s.[0]; f s.[1]; ...; f s.[String.length s - 1];
147 () .
148 val iteri : f:(int -> char -> unit) -> string -> unit
152 Same as String.iter , but the function is applied to the index of the
154 element as first argument (counting from 0), and the character itself
155 as second argument.
156 Since 4.00.0
159 val map : f:(char -> char) -> string -> string
163 String.map f s applies function f in turn to all the characters of s
166 and stores the results in a new string that is returned.
167 Since 4.00.0
170 val mapi : f:(int -> char -> char) -> string -> string
174 String.mapi f s calls f with each character of s and its index (in
177 increasing index order) and stores the results in a new string that is
178 returned.
179 Since 4.02.0
182 val trim : string -> string
186 Return a copy of the argument, without leading and trailing whitespace.
188 The characters regarded as whitespace are: ' ' , '\012' , '\n' , '\r' ,
189 and '\t' . If there is no leading nor trailing whitespace character in
190 the argument, return the original string itself, not a copy.
191 Since 4.00.0
194 val escaped : string -> string
198 Return a copy of the argument, with special characters represented by
200 escape sequences, following the lexical conventions of OCaml. If there
201 is no special character in the argument, return the original string
202 itself, not a copy. Its inverse function is Scanf.unescaped.
203 val index : string -> char -> int
207 String.index s c returns the index of the first occurrence of character
210 c in string s .
211 Raise Not_found if c does not occur in s .
213 val index_opt : string -> char -> int option
217 String.index_opt s c returns the index of the first occurrence of char‐
220 acter c in string s , or None if c does not occur in s .
221 Since 4.05
224 val rindex : string -> char -> int
228 String.rindex s c returns the index of the last occurrence of character
231 c in string s .
232 Raise Not_found if c does not occur in s .
234 val rindex_opt : string -> char -> int option
238 String.rindex_opt s c returns the index of the last occurrence of char‐
241 acter c in string s , or None if c does not occur in s .
242 Since 4.05
245 val index_from : string -> int -> char -> int
249 String.index_from s i c returns the index of the first occurrence of
252 character c in string s after position i . String.index s c is equiva‐
253 lent to String.index_from s 0 c .
254 Raise Invalid_argument if i is not a valid position in s . Raise
256 Not_found if c does not occur in s after position i .
257 val index_from_opt : string -> int -> char -> int option
261 String.index_from_opt s i c returns the index of the first occurrence
264 of character c in string s after position i or None if c does not occur
265 in s after position i .
266 String.index_opt s c is equivalent to String.index_from_opt s 0 c .
269 Raise Invalid_argument if i is not a valid position in s .
270 Since 4.05
273 val rindex_from : string -> int -> char -> int
277 String.rindex_from s i c returns the index of the last occurrence of
280 character c in string s before position i+1 . String.rindex s c is
281 equivalent to String.rindex_from s (String.length s - 1) c .
282 Raise Invalid_argument if i+1 is not a valid position in s . Raise
284 Not_found if c does not occur in s before position i+1 .
285 val rindex_from_opt : string -> int -> char -> int option
289 String.rindex_from_opt s i c returns the index of the last occurrence
292 of character c in string s before position i+1 or None if c does not
293 occur in s before position i+1 .
294 String.rindex_opt s c is equivalent to String.rindex_from_opt s
297 (String.length s - 1) c .
298 Raise Invalid_argument if i+1 is not a valid position in s .
300 Since 4.05
303 val contains : string -> char -> bool
307 String.contains s c tests if character c appears in the string s .
310 val contains_from : string -> int -> char -> bool
314 String.contains_from s start c tests if character c appears in s after
317 position start . String.contains s c is equivalent to String.con‐
318 tains_from s 0 c .
319 Raise Invalid_argument if start is not a valid position in s .
321 val rcontains_from : string -> int -> char -> bool
325 String.rcontains_from s stop c tests if character c appears in s before
328 position stop+1 .
329 Raise Invalid_argument if stop < 0 or stop+1 is not a valid position in
331 s .
332 val uppercase : string -> string
336 Deprecated. Functions operating on Latin-1 character set are depre‐
338 cated.
339 Return a copy of the argument, with all lowercase letters translated to
342 uppercase, including accented letters of the ISO Latin-1 (8859-1) char‐
343 acter set.
344 val lowercase : string -> string
348 Deprecated. Functions operating on Latin-1 character set are depre‐
350 cated.
351 Return a copy of the argument, with all uppercase letters translated to
354 lowercase, including accented letters of the ISO Latin-1 (8859-1) char‐
355 acter set.
356 val capitalize : string -> string
360 Deprecated. Functions operating on Latin-1 character set are depre‐
362 cated.
363 Return a copy of the argument, with the first character set to upper‐
366 case, using the ISO Latin-1 (8859-1) character set..
367 val uncapitalize : string -> string
371 Deprecated. Functions operating on Latin-1 character set are depre‐
373 cated.
374 Return a copy of the argument, with the first character set to lower‐
377 case, using the ISO Latin-1 (8859-1) character set..
378 val uppercase_ascii : string -> string
382 Return a copy of the argument, with all lowercase letters translated to
384 uppercase, using the US-ASCII character set.
385 Since 4.05.0
388 val lowercase_ascii : string -> string
392 Return a copy of the argument, with all uppercase letters translated to
394 lowercase, using the US-ASCII character set.
395 Since 4.05.0
398 val capitalize_ascii : string -> string
402 Return a copy of the argument, with the first character set to upper‐
404 case, using the US-ASCII character set.
405 Since 4.05.0
408 val uncapitalize_ascii : string -> string
412 Return a copy of the argument, with the first character set to lower‐
414 case, using the US-ASCII character set.
415 Since 4.05.0
418 type t = string
421 An alias for the type of strings.
424 val compare : t -> t -> int
428 The comparison function for strings, with the same specification as
430 Pervasives.compare . Along with the type t , this function compare
431 allows the module String to be passed as argument to the functors
432 Set.Make and Map.Make .
433 val equal : t -> t -> bool
437 The equal function for strings.
439 Since 4.05.0
442 val split_on_char : sep:char -> string -> string list
446 String.split_on_char sep s returns the list of all (possibly empty)
449 substrings of s that are delimited by the sep character.
450 The function's output is specified by the following invariants:
452 -The list is not empty.
455 -Concatenating its elements using sep as a separator returns a string
457 equal to the input ( String.concat (String.make 1 sep)
458 (String.split_on_char sep s) = s ).
459 -No string in the result contains the sep character.
461 Since 4.05.0
4652018-04-14 source: StringLabels(3)