1Stdlib.StringLabels(3)           OCaml library          Stdlib.StringLabels(3)
2
3
4

NAME

6       Stdlib.StringLabels - no description
7

Module

9       Module   Stdlib.StringLabels
10

Documentation

12       Module StringLabels
13        : (module Stdlib__StringLabels)
14
15
16
17
18
19
20
21
22
23   Strings
24       type t = string
25
26
27       The type for strings.
28
29
30
31       val make : int -> char -> string
32
33
34       make  n c is a string of length n with each index holding the character
35       c .
36
37
38       Raises Invalid_argument if n < 0 or n > Sys.max_string_length .
39
40
41
42       val init : int -> f:(int -> char) -> string
43
44
45       init n ~f is a string of length n with index i holding the character  f
46       i (called in increasing index order).
47
48
49       Since 4.02.0
50
51
52       Raises Invalid_argument if n < 0 or n > Sys.max_string_length .
53
54
55
56       val empty : string
57
58       The empty string.
59
60
61       Since 4.13.0
62
63
64
65       val of_bytes : bytes -> string
66
67       Return  a new string that contains the same bytes as the given byte se‐
68       quence.
69
70
71       Since 4.13.0
72
73
74
75       val to_bytes : string -> bytes
76
77       Return a new byte sequence that contains the same bytes  as  the  given
78       string.
79
80
81       Since 4.13.0
82
83
84
85       val length : string -> int
86
87
88       length s is the length (number of bytes/characters) of s .
89
90
91
92       val get : string -> int -> char
93
94
95       get  s i is the character at index i in s . This is the same as writing
96       s.[i] .
97
98
99       Raises Invalid_argument if i not an index of s .
100
101
102
103
104   Concatenating
105       Note. The (^) binary operator concatenates two strings.
106
107       val concat : sep:string -> string list -> string
108
109
110       concat ~sep ss concatenates the list of strings ss , inserting the sep‐
111       arator string sep between each.
112
113
114       Raises    Invalid_argument    if    the    result    is   longer   than
115       Sys.max_string_length bytes.
116
117
118
119       val cat : string -> string -> string
120
121
122       cat s1 s2 concatenates s1 and s2 ( s1 ^ s2 ).
123
124
125       Since 4.13.0
126
127
128       Raises  Invalid_argument  if   the   result   is   longer   then   than
129       Sys.max_string_length bytes.
130
131
132
133
134   Predicates and comparisons
135       val equal : t -> t -> bool
136
137
138       equal s0 s1 is true if and only if s0 and s1 are character-wise equal.
139
140
141       Since 4.05.0
142
143
144
145       val compare : t -> t -> int
146
147
148       compare  s0  s1  sorts s0 and s1 in lexicographical order.  compare be‐
149       haves like compare on strings but may be more efficient.
150
151
152
153       val starts_with : prefix:string -> string -> bool
154
155
156       starts_with ~ prefix s is true if and only if s starts with prefix .
157
158
159       Since 4.13.0
160
161
162
163       val ends_with : suffix:string -> string -> bool
164
165
166       ends_with ~suffix s is true if and only if s ends with suffix .
167
168
169       Since 4.13.0
170
171
172
173       val contains_from : string -> int -> char -> bool
174
175
176       contains_from s start c is true if and only if c appears in s after po‐
177       sition start .
178
179
180       Raises Invalid_argument if start is not a valid position in s .
181
182
183
184       val rcontains_from : string -> int -> char -> bool
185
186
187       rcontains_from  s  stop  c is true if and only if c appears in s before
188       position stop+1 .
189
190
191       Raises Invalid_argument if stop < 0 or stop+1 is not a  valid  position
192       in s .
193
194
195
196       val contains : string -> char -> bool
197
198
199       contains s c is String.contains_from s 0 c .
200
201
202
203
204   Extracting substrings
205       val sub : string -> pos:int -> len:int -> string
206
207
208       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
211
212       Raises Invalid_argument if pos and len do not designate  a  valid  sub‐
213       string of s .
214
215
216
217       val split_on_char : sep:char -> string -> string list
218
219
220       split_on_char  ~sep s is the list of all (possibly empty) substrings of
221       s that are delimited by the character sep .
222
223       The function's result is specified by the following invariants:
224
225       -The list is not empty.
226
227       -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
231       -No string in the result contains the sep character.
232
233
234
235       Since 4.05.0
236
237
238
239
240   Transforming
241       val map : f:(char -> char) -> string -> string
242
243
244       map  f  s is the string resulting from applying f to all the characters
245       of s in increasing order.
246
247
248       Since 4.00.0
249
250
251
252       val mapi : f:(int -> char -> char) -> string -> string
253
254
255       mapi ~f s is like StringLabels.map but the index of  the  character  is
256       also passed to f .
257
258
259       Since 4.02.0
260
261
262
263       val fold_left : f:('a -> char -> 'a) -> init:'a -> string -> 'a
264
265
266       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
269
270       Since 4.13.0
271
272
273
274       val fold_right : f:(char -> 'a -> 'a) -> string -> init:'a -> 'a
275
276
277       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
280
281       Since 4.13.0
282
283
284
285       val for_all : f:(char -> bool) -> string -> bool
286
287
288       for_all p s checks if all characters in s satisfy the predicate p .
289
290
291       Since 4.13.0
292
293
294
295       val exists : f:(char -> bool) -> string -> bool
296
297
298       exists  p  s checks if at least one character of s satisfies the predi‐
299       cate p .
300
301
302       Since 4.13.0
303
304
305
306       val trim : string -> string
307
308
309       trim s is s without leading and trailing whitespace. Whitespace charac‐
310       ters are: ' ' , '\x0C' (form feed), '\n' , '\r' , and '\t' .
311
312
313       Since 4.00.0
314
315
316
317       val escaped : string -> string
318
319
320       escaped s is s with special characters represented by escape sequences,
321       following the lexical conventions of OCaml.
322
323       All characters outside the US-ASCII printable range [0x20;0x7E] are es‐
324       caped, as well as backslash (0x2F) and double-quote (0x22).
325
326       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
330
331       Raises    Invalid_argument    if    the    result    is   longer   than
332       Sys.max_string_length bytes.
333
334
335
336       val uppercase_ascii : string -> string
337
338
339       uppercase_ascii s is s with all lowercase letters translated to  upper‐
340       case, using the US-ASCII character set.
341
342
343       Since 4.05.0
344
345
346
347       val lowercase_ascii : string -> string
348
349
350       lowercase_ascii  s is s with all uppercase letters translated to lower‐
351       case, using the US-ASCII character set.
352
353
354       Since 4.05.0
355
356
357
358       val capitalize_ascii : string -> string
359
360
361       capitalize_ascii s is s with the first character set to uppercase,  us‐
362       ing the US-ASCII character set.
363
364
365       Since 4.05.0
366
367
368
369       val uncapitalize_ascii : string -> string
370
371
372       uncapitalize_ascii  s  is  s with the first character set to lowercase,
373       using the US-ASCII character set.
374
375
376       Since 4.05.0
377
378
379
380
381   Traversing
382       val iter : f:(char -> unit) -> string -> unit
383
384
385       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
388
389
390       val iteri : f:(int -> char -> unit) -> string -> unit
391
392
393       iteri  is  like  StringLabels.iter , but the function is also given the
394       corresponding character index.
395
396
397       Since 4.00.0
398
399
400
401
402   Searching
403       val index_from : string -> int -> char -> int
404
405
406       index_from s i c is the index of the first occurrence of c in  s  after
407       position i .
408
409
410       Raises Not_found if c does not occur in s after position i .
411
412
413       Raises Invalid_argument if i is not a valid position in s .
414
415
416
417       val index_from_opt : string -> int -> char -> int option
418
419
420       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
423
424       Since 4.05
425
426
427       Raises Invalid_argument if i is not a valid position in s .
428
429
430
431       val rindex_from : string -> int -> char -> int
432
433
434       rindex_from s i c is the index of the last occurrence of c in s  before
435       position i+1 .
436
437
438       Raises Not_found if c does not occur in s before position i+1 .
439
440
441       Raises Invalid_argument if i+1 is not a valid position in s .
442
443
444
445       val rindex_from_opt : string -> int -> char -> int option
446
447
448       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
451
452       Since 4.05
453
454
455       Raises Invalid_argument if i+1 is not a valid position in s .
456
457
458
459       val index : string -> char -> int
460
461
462       index s c is String.index_from s 0 c .
463
464
465
466       val index_opt : string -> char -> int option
467
468
469       index_opt s c is String.index_from_opt s 0 c .
470
471
472       Since 4.05
473
474
475
476       val rindex : string -> char -> int
477
478
479       rindex s c is String.rindex_from s (length s - 1) c .
480
481
482
483       val rindex_opt : string -> char -> int option
484
485
486       rindex_opt s c is String.rindex_from_opt s (length s - 1) c .
487
488
489       Since 4.05
490
491
492
493
494   Strings and Sequences
495       val to_seq : t -> char Seq.t
496
497
498       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
502
503       Since 4.07
504
505
506
507       val to_seqi : t -> (int * char) Seq.t
508
509
510       to_seqi s is like StringLabels.to_seq but also tuples the corresponding
511       index.
512
513
514       Since 4.07
515
516
517
518       val of_seq : char Seq.t -> t
519
520
521       of_seq s is a string made of the sequence's characters.
522
523
524       Since 4.07
525
526
527
528
529   UTF decoding and validations
530   UTF-8
531       val get_utf_8_uchar : t -> int -> Uchar.utf_decode
532
533
534       get_utf_8_uchar b i decodes an UTF-8 character at index i in b .
535
536
537
538       val is_valid_utf_8 : t -> bool
539
540
541       is_valid_utf_8 b is true if and only if b contains valid UTF-8 data.
542
543
544
545
546   UTF-16BE
547       val get_utf_16be_uchar : t -> int -> Uchar.utf_decode
548
549
550       get_utf_16be_uchar b i decodes an UTF-16BE character at index i in b .
551
552
553
554       val is_valid_utf_16be : t -> bool
555
556
557       is_valid_utf_16be  b  is  true if and only if b contains valid UTF-16BE
558       data.
559
560
561
562
563   UTF-16LE
564       val get_utf_16le_uchar : t -> int -> Uchar.utf_decode
565
566
567       get_utf_16le_uchar b i decodes an UTF-16LE character at index i in b .
568
569
570
571       val is_valid_utf_16le : t -> bool
572
573
574       is_valid_utf_16le b is true if and only if b  contains  valid  UTF-16LE
575       data.
576
577
578
579
580   Deprecated functions
581       val create : int -> bytes
582
583       Deprecated.   This  is  a  deprecated  alias of Bytes.create / BytesLa‐
584       bels.create .
585
586
587
588       create n returns a fresh byte sequence of length n .  The  sequence  is
589       uninitialized and contains arbitrary bytes.
590
591
592       Raises Invalid_argument if n < 0 or n > Sys.max_string_length .
593
594
595
596       val set : bytes -> int -> char -> unit
597
598       Deprecated.   This is a deprecated alias of Bytes.set / BytesLabels.set
599       .
600
601
602
603       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
606
607       Raises Invalid_argument if n is not a valid index in s .
608
609
610
611       val  blit  :  src:string  -> src_pos:int -> dst:bytes -> dst_pos:int ->
612       len:int -> unit
613
614
615       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
619
620       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
624
625
626       val copy : string -> string
627
628       Deprecated.  Because strings are immutable, it doesn't make much  sense
629       to make identical copies of them.
630
631
632       Return a copy of the given string.
633
634
635
636       val fill : bytes -> pos:int -> len:int -> char -> unit
637
638       Deprecated.   This  is  a  deprecated  alias  of  Bytes.fill / BytesLa‐
639       bels.fill .
640
641
642
643       fill s ~pos ~len c modifies byte sequence s  in  place,  replacing  len
644       bytes by c , starting at pos .
645
646
647       Raises  Invalid_argument  if  pos and len do not designate a valid sub‐
648       string of s .
649
650
651
652       val uppercase : string -> string
653
654       Deprecated.  Functions operating on Latin-1 character  set  are  depre‐
655       cated.
656
657
658       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
662
663
664       val lowercase : string -> string
665
666       Deprecated.   Functions  operating  on Latin-1 character set are depre‐
667       cated.
668
669
670       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
674
675
676       val capitalize : string -> string
677
678       Deprecated.  Functions operating on Latin-1 character  set  are  depre‐
679       cated.
680
681
682       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
685
686
687       val uncapitalize : string -> string
688
689       Deprecated.  Functions operating on Latin-1 character  set  are  depre‐
690       cated.
691
692
693       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
696
697
698
699   Binary decoding of integers
700       The functions in this section binary decode integers from strings.
701
702       All following functions raise Invalid_argument if the characters needed
703       at index i to decode the integer are not available.
704
705       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
710       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
713       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
718       val get_uint8 : string -> int -> int
719
720
721       get_uint8 b i is b 's unsigned 8-bit integer starting at character  in‐
722       dex i .
723
724
725       Since 4.13.0
726
727
728
729       val get_int8 : string -> int -> int
730
731
732       get_int8 b i is b 's signed 8-bit integer starting at character index i
733       .
734
735
736       Since 4.13.0
737
738
739
740       val get_uint16_ne : string -> int -> int
741
742
743       get_uint16_ne b i is b 's native-endian unsigned 16-bit integer  start‐
744       ing at character index i .
745
746
747       Since 4.13.0
748
749
750
751       val get_uint16_be : string -> int -> int
752
753
754       get_uint16_be  b  i is b 's big-endian unsigned 16-bit integer starting
755       at character index i .
756
757
758       Since 4.13.0
759
760
761
762       val get_uint16_le : string -> int -> int
763
764
765       get_uint16_le b i is b 's little-endian unsigned 16-bit integer  start‐
766       ing at character index i .
767
768
769       Since 4.13.0
770
771
772
773       val get_int16_ne : string -> int -> int
774
775
776       get_int16_ne  b  i is b 's native-endian signed 16-bit integer starting
777       at character index i .
778
779
780       Since 4.13.0
781
782
783
784       val get_int16_be : string -> int -> int
785
786
787       get_int16_be b i is b 's big-endian signed 16-bit integer  starting  at
788       character index i .
789
790
791       Since 4.13.0
792
793
794
795       val get_int16_le : string -> int -> int
796
797
798       get_int16_le  b  i is b 's little-endian signed 16-bit integer starting
799       at character index i .
800
801
802       Since 4.13.0
803
804
805
806       val get_int32_ne : string -> int -> int32
807
808
809       get_int32_ne b i is b 's native-endian 32-bit integer starting at char‐
810       acter index i .
811
812
813       Since 4.13.0
814
815
816
817       val get_int32_be : string -> int -> int32
818
819
820       get_int32_be  b i is b 's big-endian 32-bit integer starting at charac‐
821       ter index i .
822
823
824       Since 4.13.0
825
826
827
828       val get_int32_le : string -> int -> int32
829
830
831       get_int32_le b i is b 's little-endian 32-bit integer starting at char‐
832       acter index i .
833
834
835       Since 4.13.0
836
837
838
839       val get_int64_ne : string -> int -> int64
840
841
842       get_int64_ne b i is b 's native-endian 64-bit integer starting at char‐
843       acter index i .
844
845
846       Since 4.13.0
847
848
849
850       val get_int64_be : string -> int -> int64
851
852
853       get_int64_be b i is b 's big-endian 64-bit integer starting at  charac‐
854       ter index i .
855
856
857       Since 4.13.0
858
859
860
861       val get_int64_le : string -> int -> int64
862
863
864       get_int64_le b i is b 's little-endian 64-bit integer starting at char‐
865       acter index i .
866
867
868       Since 4.13.0
869
870
871
872
873
874OCamldoc                          2023-01-23            Stdlib.StringLabels(3)
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