Basic String Utils
include module type of struct include String endmake n c is a string of length n with each index holding the character c.
init n f is a string of length n with index i holding the character f i (called in increasing index order).
get s i is the character at index i in s. This is the same as writing s.[i].
Return a new string that contains the same bytes as the given byte sequence.
Return a new byte sequence that contains the same bytes as the given string.
Note. The Stdlib.(^) binary operator concatenates two strings.
concat sep ss concatenates the list of strings ss, inserting the separator string sep between each.
starts_with ~prefix s is true if and only if s starts with prefix.
ends_with ~suffix s is true if and only if s ends with suffix.
contains_from s start c is true if and only if c appears in s after position start.
rcontains_from s stop c is true if and only if c appears in s before position stop+1.
contains s c is String.contains_from s 0 c.
sub s pos len is a string of length len, containing the substring of s that starts at position pos and has length len.
map f s is the string resulting from applying f to all the characters of s in increasing order.
mapi f s is like map but the index of the character is also passed to f.
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.
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.
trim s is s without leading and trailing whitespace. Whitespace characters are: ' ', '\x0C' (form feed), '\n', '\r', and '\t'.
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).
uppercase_ascii s is s with all lowercase letters translated to uppercase, using the US-ASCII character set.
lowercase_ascii s is s with all uppercase letters translated to lowercase, using the US-ASCII character set.
capitalize_ascii s is s with the first character set to uppercase, using the US-ASCII character set.
uncapitalize_ascii s is s with the first character set to lowercase, using the US-ASCII character set.
iteri is like iter, but the function is also given the corresponding character index.
index_from s i c is the index of the first occurrence of c in s after position i.
index_from_opt s i c is the index of the first occurrence of c in s after position i (if any).
rindex_from s i c is the index of the last occurrence of c in s before position i+1.
rindex_from_opt s i c is the index of the last occurrence of c in s before position i+1 (if any).
index s c is String.index_from s 0 c.
index_opt s c is String.index_from_opt s 0 c.
rindex s c is String.rindex_from s (length s - 1) c.
rindex_opt s c is String.rindex_from_opt s (length s - 1) c.
to_seqi s is like to_seq but also tuples the corresponding index.
val get_utf_8_uchar : t -> int -> Uchar.utf_decodeget_utf_8_uchar b i decodes an UTF-8 character at index i in b.
val is_valid_utf_8 : t -> boolis_valid_utf_8 b is true if and only if b contains valid UTF-8 data.
val get_utf_16be_uchar : t -> int -> Uchar.utf_decodeget_utf_16be_uchar b i decodes an UTF-16BE character at index i in b.
val is_valid_utf_16be : t -> boolis_valid_utf_16be b is true if and only if b contains valid UTF-16BE data.
val get_utf_16le_uchar : t -> int -> Uchar.utf_decodeget_utf_16le_uchar b i decodes an UTF-16LE character at index i in b.
val is_valid_utf_16le : t -> boolis_valid_utf_16le b is true if and only if b contains valid UTF-16LE data.
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.
get_uint8 b i is b's unsigned 8-bit integer starting at character index i.
get_int8 b i is b's signed 8-bit integer starting at character index i.
get_uint16_ne b i is b's native-endian unsigned 16-bit integer starting at character index i.
get_uint16_be b i is b's big-endian unsigned 16-bit integer starting at character index i.
get_uint16_le b i is b's little-endian unsigned 16-bit integer starting at character index i.
get_int16_ne b i is b's native-endian signed 16-bit integer starting at character index i.
get_int16_be b i is b's big-endian signed 16-bit integer starting at character index i.
get_int16_le b i is b's little-endian signed 16-bit integer starting at character index i.
get_int32_ne b i is b's native-endian 32-bit integer starting at character index i.
val seeded_hash : int -> t -> intA 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.
get_int32_be b i is b's big-endian 32-bit integer starting at character index i.
get_int32_le b i is b's little-endian 32-bit integer starting at character index i.
get_int64_ne b i is b's native-endian 64-bit integer starting at character index i.
get_int64_be b i is b's big-endian 64-bit integer starting at character index i.
val length : t -> intlength s returns the length (number of characters) of the given string s.
blit src src_pos dst dst_pos len copies len characters from string src starting at character indice src_pos, to the Bytes sequence dst starting at character indice dst_pos. Like String.blit. Compatible with the -safe-string option.
val fold : ('a -> char -> 'a) -> 'a -> t -> 'afold f init s folds on chars by increasing index. Computes f(… (f (f init s.[0]) s.[1]) …) s.[n-1].
val foldi : ('a -> int -> char -> 'a) -> 'a -> t -> 'afoldi f init s is just like fold, but it also passes in the index of each chars as second argument to the folded function f.
to_seq s returns the Seq.t of characters contained in the string s. Renamed from to std_seq since 3.0.
val to_list : t -> char listto_list s returns the list of characters contained in the string s.
pp_buf buf s prints s to the buffer buf. Renamed from pp since 2.0.
val pp : Format.formatter -> t -> unitpp f s prints the string s within quotes to the formatter f. Renamed from print since 2.0.
compare s1 s2 compares the strings s1 and s2 and returns an integer that indicates their relative position in the sort order.
pad ~side ~c n s ensures that the string s is at least n bytes long, and pads it on the side with c if it's not the case.
val of_gen : char gen -> stringof_gen gen converts a gen of characters to a string.
val of_iter : char iter -> stringof_iter iter converts an iter of characters to a string.
val of_seq : char Seq.t -> stringof_seq seq converts a seq of characters to a string. Renamed from of_std_seq since 3.0.
to_array s returns the array of characters contained in the string s.
find ~start ~sub s returns the starting index of the first occurrence of sub within s or -1.
val find_all : ?start:int -> sub:string -> string -> int genfind_all ~start ~sub s finds all occurrences of sub in s, even overlapping instances and returns them in a generator gen.
find_all_l ~sub s finds all occurrences of sub in s and returns them in a list.
mem ~start ~sub s is true iff sub is a substring of s.
rfind ~sub s finds sub in string s from the right, returns its first index or -1. Should only be used with very small sub.
replace ~which ~sub ~by s replaces some occurrences of sub by by in s.
is_sub ~sub ~sub_pos s ~pos ~sub_len returns true iff the substring of sub starting at position sub_pos and of length sub_len is a substring of s starting at position pos.
chop_prefix ~pre s removes pre from s if pre really is a prefix of s, returns None otherwise.
chop_suffix ~suf s removes suf from s if suf really is a suffix of s, returns None otherwise.
val lines_gen : string -> string genlines_gen s returns the gen of the lines of s (splits along '\n').
val lines_iter : string -> string iterlines_iter s returns the iter of the lines of s (splits along '\n').
val lines_seq : string -> string Seq.tlines_seq s returns the Seq.t of the lines of s (splits along '\n').
val concat_gen : sep:string -> string gen -> stringconcat_gen ~sep gen concatenates all strings of gen, separated with sep.
val concat_seq : sep:string -> string Seq.t -> stringconcat_seq ~sep seq concatenates all strings of seq, separated with sep.
val concat_iter : sep:string -> string iter -> stringconcat_iter ~sep iter concatenates all strings of iter, separated with sep.
val unlines_gen : string gen -> stringunlines_gen gen concatenates all strings of gen, separated with '\n'.
val unlines_iter : string iter -> stringunlines_iter iter concatenates all strings of iter, separated with '\n'.
val unlines_seq : string Seq.t -> stringunlines_seq seq concatenates all strings of seq, separated with '\n'.
set s i c creates a new string which is a copy of s, except for index i, which becomes c.
iter f s applies function f on each character of s. Alias to String.iter.
filter_map f s calls (f a0) (f a1) … (f an) where a0 … an are the characters of s. It returns the string of characters ci such as f ai = Some ci (when f returns None, the corresponding element of s is discarded).
filter f s discards characters of s not satisfying f.
uniq eq s remove consecutive duplicate characters in s.
flat_map ~sep f s maps each chars of s to a string, then concatenates them all.
for_all f s is true iff all characters of s satisfy the predicate f.
exists f s is true iff some character of s satisfy the predicate f.
drop_while f s discards any characters of s starting from the left, up to the first character c not satisfying f c.
rdrop_while f s discards any characters of s starting from the right, up to the first character c not satisfying f c.
ltrim s trims space on the left (see String.trim for more details).
rtrim s trims space on the right (see String.trim for more details).
iter2 f s1 s2 iterates on pairs of chars.
iteri2 f s1 s2 iterates on pairs of chars with their index.
fold2 f init s1 s2 folds on pairs of chars.
for_all2 f s1 s2 returns true iff all pairs of chars satisfy the predicate f.
exists2 f s1 s2 returns true iff a pair of chars satisfy the predicate f.
Those functions are deprecated in String since 4.03, so we provide a stable alias for them even in older versions.
equal_caseless s1 s2 compares s1 and s2 without respect to ascii lowercase.
A relatively efficient algorithm for finding sub-strings.
module Find : sig ... endmodule Split : sig ... endsplit_on_char by s splits the string s along the given char by.
split ~by s splits the string s along the given string by. Alias to Split.list_cpy.
compare_versions s1 s2 compares version strings s1 and s2, considering that numbers are above text.
compare_natural s1 s2 is the Natural Sort Order, comparing chunks of digits as natural numbers. https://en.wikipedia.org/wiki/Natural_sort_order
edit_distance ~cutoff s1 s2 is the edition distance between the two strings s1 and s2. This satisfies the classical distance axioms: it is always positive, symmetric, and satisfies the formula distance s1 s2 + distance s2 s3 >= distance s1 s3.
module Infix : sig ... end