(** Sane OCaml String API *) type ('a, 'b) result = [ | `Ok of 'a | `Error of 'b ] (** The type [result] is a reusable version the classical [Result.t] type. *) module type OUTPUT_MODEL = sig (** A monadic thread model (like [Lwt], [Async]) and an [output] function. *) type ('a, 'b, 'c) thread (** The type of the threads, the type parameters are there in case the user needs up to 3 of them. For instance, if implement with [Lwt], we will have [type ('a, 'b, 'c) thread = 'a Lwt.t], but with [Pvem.DEFERRED_RESULT]: [type ('a, 'b, 'c) thread = ('a, 'b) Deferred_result.t]. *) type ('a, 'b, 'c) channel (** The of the channels, channels can have up to 3 type-parameters too. *) val return: 'a -> ('a, 'b, 'c) thread (** The monadic [return]. *) val bind: ('a, 'b, 'c) thread -> ('a -> ('d, 'b, 'c) thread) -> ('d, 'b, 'c) thread (** The monadic [bind]. *) val output: ('a, 'b, 'c) channel -> String.t -> (unit, 'e, 'f) thread (** The function to output a given native string to a channel. *) end module type NATIVE_CONVERSIONS = sig (** API definition of conversions from native OCaml strings to a given string type or vice-versa. *) type t (** The string type. *) val of_native_string: string -> (t, [> `wrong_char_at of int ]) result (** Convert a native string to the current representation. [of_native_string] returns [`Error (`wrong_char_at index)] when the native string contains a character not representable with the type [character]. *) val of_native_substring: string -> offset:int -> length:int -> (t, [> `wrong_char_at of int | `out_of_bounds ]) result (** Convert a native string like [of_native_string] but take a subset of the string. *) val to_native_string: t -> string (** Serialize the string to a native string. *) end module type BASIC_CHARACTER = sig (** The minimal API implemented by characters. *) type t (** The type representing the character. *) val of_native_char: char -> t option (** Import a native [char], returns [None] if the character is not representable. *) val of_int: int -> t option (** Import an integer, returns [None] if there is no character for that value. *) val to_int: t -> int (** Returns the integer representation of the character. *) val size: t -> int (** Get the size of the character, the exact semantics are implementation-specific (c.f. {!write_to_native_string}) *) val write_to_native_string: t -> buf:String.t -> index:int -> (int, [> `out_of_bounds]) result (** [write_to_native_string c ~buf ~index] serializes the character [c] at position [index] in the native string [buf] (writing [size c] units). Note, as with {!size} that the meaning of [index] is implementation dependent (can be the {i index-th} byte, the {i index-th} bit, etc.). *) val to_native_string: t -> String.t (** [to_native_string c] creates a string containing the serialization of the character [c] (if [size c] is not a multiple of 8, the end-padding is undefined). *) val read_from_native_string: buf:String.t -> index:int -> (t * int) option (** Read a character at a given [index] in a native string, returns [Some (c, s)], the character [c] and the number of units read [s], or [None] if there is no representable/valid character at that index. *) val to_string_hum: t -> String.t (** Convert the character to a human-readable native string (in the spirit of [sprintf "%s"]). *) val compare: t -> t -> int (** Comparison function (as expected by most common functors in the ecosystem). *) val is_whitespace: t -> bool (** Tell whether a character is considered whitespace. *) end module type BASIC_STRING = sig (** The minimal API implemented by string modules. *) type character (** A string is a string of characters. *) type t (** The type of the string. *) val empty: t (** An “empty” string. *) val is_empty: t -> bool (** Test whether a string is empty. *) val make: int -> character -> t (** Build a new string like [String.make]. *) val length: t -> int (** Get the length of the string (i.e. the number of characters). *) val of_character: character -> t (** Make a string with one character. *) val of_character_list: character list -> t (** Make a string out of a list of characters. *) val to_character_list: t -> character list (** Explode a string into a list of characters. *) val get: t -> index:int -> character option (** Get the n-th char, indexes are not necessarily bytes, they can be bits. [get] returns [None] when [index] is out of bounds. *) val set: t -> index:int -> v:character -> t option (** [set str ~index ~v] creates a new string equal to [t] with character [v] at position [index]. [set] returns [None] when [index] is out of bounds. *) val get_exn: t -> index:int -> character (** Like [get] but fail with an exception *) val set_exn: t -> index:int -> v:character -> t (** Like [set] but fail with an exception *) val concat: ?sep:t -> t list -> t (** The classical [concat] function. *) include NATIVE_CONVERSIONS with type t := t (** By including {!NATIVE_CONVERSIONS}, a basic string provides {!NATIVE_CONVERSIONS.of_native_string}, {!NATIVE_CONVERSIONS.of_native_substring}, and {!NATIVE_CONVERSIONS.to_native_string}. *) val to_string_hum: t -> string (** Convert the string to a human-readable native string (à la [sprintf "%S"]). *) val fold: t -> init:'a -> f:('a -> character -> 'a) -> 'a (** The standard [fold] function, see [List.fold_left] for example. *) val foldi: t -> init:'a -> f:(int -> 'a -> character -> 'a) -> 'a (** Pass an accumulator over the string's characters and their ordinals, starting with the first; left most. *) val fold2_exn: t -> t -> init:'a -> f:('a -> character -> character -> 'a) -> 'a (** The standard [fold2] function, see [List.fold_left2] for example. Fails on [t]s of different length. *) val compare: t -> t -> int (** Comparison function (as expected by most common functors in the ecosystem). *) val sub: t -> index:int -> length:int -> t option (** Get the sub-string of size [length] at position [index]. If [length] is 0, [sub] returns [Some empty] whichever the other parameters are. *) val sub_exn: t -> index:int -> length:int -> t (** Do like [sub] but throw an exception instead of returning [None] *) val slice: ?start:int -> ?finish:int -> t -> t option (** Create a sub-string from the [start] (default 0, within \[0,length\)) position to before the [finish] (default length, within \[0,length\]) if all of the indices are in bounds. *) val slice_exn: ?start:int -> ?finish:int -> t -> t (** Like [slice] but throw an exception instead of returning [None] *) val is_prefix: t -> prefix:t -> bool (** Does [t] start with [prefix] ? *) val is_suffix: t -> suffix:t -> bool (** Does [t] end with [suffix] ? *) val chop_prefix_exn: t -> prefix:t -> t (** Return a copy of [t] with [prefix] removed from the beginning. Throws Invalid_argument if [t] does not start with [prefix]. *) val chop_prefix: t -> prefix:t -> t option (** Like [chop_prefix_exn] but return [None] instead of throwing an exception. *) val chop_suffix_exn: t -> suffix:t -> t (** Return a copy of [t] with [suffix] removed from the end. Throws Invalid_argument if [t] does not end with [suffix]. *) val chop_suffix: t -> suffix:t -> t option (** Like [chop_suffix_exn] but return [None] instead of throwing an exception. *) val split_at: t -> index:int -> t * t (** Return a tuple where the first string is a prefix of the specified length and the second is the rest. If index is [=< 0] then the first element is empty and the string is returned in the second element, similarly if the index is [>= length t] then the first element is [t] and the second is [empty]. *) val take: t -> index:int -> t (** Just the first part of split_at *) val drop: t -> index:int -> t (** Just the second part of split_at *) val compare_substring: t * int * int -> t * int * int -> int (** Comparison function for substrings: use as [compare_substring (s1, index1, length1) (s2, index2, length2)]. Note that out-of-bounds accesses will {b not} be reported: for performance reasons, if the result can be decided with the smallest sub-string then [compare_substring] won't look further. However, if {!compare_substring_strict} returns [Some c] then [compare_substring] {i must} return [d] such as [c] = [d] or [c] × [d] > 0 (i.e. strictly same sign). In other words, is [sub a ~index:ia ~length:la] returns [Some suba] and [sub b ~index:ib ~length:lb] returns [Some subb], then [compare_substring (a, ia, la) (b, ib, lb)] will behave like [compare suba subb] (again, with the same sign). *) val compare_substring_strict: t * int * int -> t * int * int -> int option (** Do like {!compare_substring} but return [Some _] only when it is well defined (same validity criteria as {!sub}: if [length] is [0], [index] is irrelevant). Depending on the backend implementation, this function might be significantly slower than [compare_substring] (for example when calls to [length] are not {i O(1)}). *) val iter: t -> f:(character -> unit) -> unit (** Apply [f] on every character successively. *) val iteri: t -> f:(int -> character -> unit) -> unit (** Apply [f] on every character and its index. *) val iter_reverse: t -> f:(character -> unit) -> unit (** Apply [f] on every character successively in reverse order. *) val rev: t -> t (** Reverse the string. **) val map: t -> f:(character -> character) -> t (** Make a new string by applying [f] to all characters of the input. *) val mapi: t -> f:(int -> character -> character) -> t (** Make a new string by applying [f] to all characters and their indices. *) val map2_exn: t -> t -> f:(character -> character -> character) -> t (** Make a new string by applying [f] to all pairs of characters of the inputs. Fail if strings are not the same length. *) val for_all: t -> f:(character -> bool) -> bool (** Return [true] if-and-only-if [f] returns [true] on all characters. *) val exists: t -> f:(character -> bool) -> bool (** Return [true] if-and-only-if [f] returns [true] on at least one character. *) val take_while: t -> f:(character -> bool) -> t (** Take a prefix of the string until [f] returns [false]. *) val take_while_with_index: t -> f:(int -> character -> bool) -> t (** Like {!take_while} but the function also takes the current index. *) val index_of_character: t -> ?from:int -> character -> int option (** Find the first occurrence of a character in the string (starting at position [from]). Default value for [from] is [0]. If [from] is negative, [0] will be used. If [from >= length t], [None] will be returned. *) val index_of_character_reverse: t -> ?from:int -> character -> int option (** Do like [index_of_character] but start from the end of the string. Default value for [from] is [length t - 1] (end of the string). If [from] is negative, [None] will be returned. If [from >= length t], [length t - 1] will be used. *) val index_of_string: ?from:int -> ?sub_index:int -> ?sub_length:int -> t -> sub:t -> int option (** Find the first occurrence of the substring [(sub, sub_index, sub_length)] in a given string, starting at index [from]. The [from] parameter behaves like for {!index_of_character}. The [(sub_index, sub_length)] parameters are constrained to [(0, length sub)], for example, if [sub] is ["abc"], [(-1, 4)] will be equivalent to [(0, 3)], [(1, 3)] will be equivalent to [(1, 2)]. Searching for an empty string [from] a valid position always succeeds at that position. *) val index_of_string_reverse: ?from:int -> ?sub_index:int -> ?sub_length:int -> t -> sub:t -> int option (** Do like [index_of_string] but start from the end of the string. The [from] parameter behaves like for {!index_of_character_reverse}. The [(sub_index, sub_length)] parameters are constrained like in {!index_of_string}. *) val find: ?from:int -> ?length:int -> t -> f:(character -> bool) -> int option (** Find the index of the first character [c] for which [f c] is [true]. One can restrict to the sub-string [(from, length)] (the default is to use the whole string, “out-of-bound” values are restricted to the bounds of the string). *) val find_reverse: ?from:int -> ?length:int -> t -> f:(character -> bool) -> int option (** Find the index of the last character [c] for which [f c] is [true]. One can restrict to the reverse sub-string [(from, length)] (the default is to use the whole string, “out-of-bound” values are restricted to the bounds of the string). *) val filter_map: ?from:int -> ?length:int -> t -> f:(character -> character option) -> t (** Create a new string with the characters for which [f c] returned [Some c]. One can restrict to the sub-string [(from, length)] (the default is to use the whole string, “out-of-bound” values are restricted to the bounds of the string). *) val filter: ?from:int -> ?length:int -> t -> f:(character -> bool) -> t (** Create a new string with the characters for which [f c] is true. One can restrict to the sub-string [(from, length)] (the default is to use the whole string, “out-of-bound” values are restricted to the bounds of the string). *) val split: t -> on:[ `Character of character | `String of t ] -> t list (** Split the string using [on] as separator. Splitting the empty string returns [[empty]], splitting [on] the empty string explodes the string into a list of one-character strings. *) val strip: ?on:[`Both | `Left | `Right] -> ?whitespace:(character -> bool) -> t -> t (** Remove any whitespace characters at the beginning and/or the end of the string (default [`Both]). The default is to call the {!BASIC_CHARACTER.is_whitespace} function of the implemented character. *) module Make_output: functor (Model: OUTPUT_MODEL) -> sig val output: ('a, 'b, 'c) Model.channel -> t -> (unit, 'e, 'f) Model.thread (** Output a string to a channel. *) end (** [Make_output(Asynchronous_output_model)] provides a function {!Make_output.output} given any {!OUTPUT_MODEL}. *) end module type UNSAFELY_MUTABLE = sig (** This interface defines functions that may be implemented by particular string types that are actually mutable. They are considered “unsafe” because they break the immutability invariants assumed by the rest of this library; you'd better know what you're doing. *) type t type character val mutate: t -> index:int -> character -> (unit, [> `out_of_bounds ]) result (** Set the [index]-th character of the string. *) val mutate_exn: t -> index:int -> character -> unit (** Set the [index]-th character of the string, but fail with a non-specified exception. *) val blit: src:t -> src_index:int -> dst:t -> dst_index:int -> length:int -> (unit, [> `out_of_bounds ]) result (** Copy [length] characters from [src] (starting at [src_index]) to [dst] (starting at [dst_index]). *) val blit_exn: src:t -> src_index:int -> dst:t -> dst_index:int -> length:int -> unit (** Like {!blit} but fail with a non-specified exception. *) end open Printf (* Internal “Pervasives” module, to be used in all the following implementations. *) module Internal_pervasives = struct module List = ListLabels module String = StringLabels let (|>) x f = f x let return x : (_, _) result = `Ok x let fail x : (_, _) result = `Error x let bind x f = match x with | `Ok o -> f o | `Error e -> fail e let (>>=) = bind let dbg fmt = printf ("DBG: " ^^ fmt ^^ "\n%!") (* The function `List.map` adapted from `Core_kernel`'s way of unrolling the loops. *) module Core_list_map = struct let map_slow l ~f = List.rev (List.rev_map ~f l) let rec count_map ~f l ctr = match l with | [] -> [] | [x1] -> let f1 = f x1 in [f1] | [x1; x2] -> let f1 = f x1 in let f2 = f x2 in [f1; f2] | [x1; x2; x3] -> let f1 = f x1 in let f2 = f x2 in let f3 = f x3 in [f1; f2; f3] | [x1; x2; x3; x4] -> let f1 = f x1 in let f2 = f x2 in let f3 = f x3 in let f4 = f x4 in [f1; f2; f3; f4] | x1 :: x2 :: x3 :: x4 :: x5 :: tl -> let f1 = f x1 in let f2 = f x2 in let f3 = f x3 in let f4 = f x4 in let f5 = f x5 in f1 :: f2 :: f3 :: f4 :: f5 :: (if ctr > 1000 then map_slow ~f tl else count_map ~f tl (ctr + 1)) let map l ~f = count_map ~f l 0 let mapi_slow l ~f ~i = let _, r = List.fold_left l ~f:(fun (i, a) e -> (i + 1, ((f i e)::a))) ~init:(i,[]) in List.rev r let rec count_mapi ~f l ctr = match l with | [] -> [] | [x1] -> let f1 = f ctr x1 in [f1] | [x1; x2] -> let f1 = f ctr x1 in let f2 = f (ctr + 1) x2 in [f1; f2] | [x1; x2; x3] -> let f1 = f ctr x1 in let f2 = f (ctr + 1) x2 in let f3 = f (ctr + 2) x3 in [f1; f2; f3] | [x1; x2; x3; x4] -> let f1 = f ctr x1 in let f2 = f (ctr + 1) x2 in let f3 = f (ctr + 2) x3 in let f4 = f (ctr + 3) x4 in [f1; f2; f3; f4] | x1 :: x2 :: x3 :: x4 :: x5 :: tl -> let f1 = f ctr x1 in let f2 = f (ctr + 1) x2 in let f3 = f (ctr + 2) x3 in let f4 = f (ctr + 3) x4 in let f5 = f (ctr + 4) x5 in f1 :: f2 :: f3 :: f4 :: f5 :: (if ctr > 5000 then mapi_slow ~f ~i:(ctr + 5) tl else count_mapi ~f tl (ctr + 5)) let mapi l ~f = count_mapi ~f l 0 let map2_slow l1 l2 ~f = List.rev (List.rev_map2 ~f l1 l2) let rec count_map2_exn ~f l1 l2 ctr = match l1, l2 with | [], [] -> [] | [x1], [y1] -> let f1 = f x1 y1 in [f1] | [x1; x2], [y1; y2] -> let f1 = f x1 y1 in let f2 = f x2 y2 in [f1; f2] | [x1; x2; x3], [y1; y2; y3] -> let f1 = f x1 y1 in let f2 = f x2 y2 in let f3 = f x3 y3 in [f1; f2; f3] | [x1; x2; x3; x4], [y1; y2; y3; y4] -> let f1 = f x1 y1 in let f2 = f x2 y2 in let f3 = f x3 y3 in let f4 = f x4 y4 in [f1; f2; f3; f4] | x1 :: x2 :: x3 :: x4 :: x5 :: tl1, y1 :: y2 :: y3 :: y4 :: y5 :: tl2 -> let f1 = f x1 y1 in let f2 = f x2 y2 in let f3 = f x3 y3 in let f4 = f x4 y4 in let f5 = f x5 y5 in f1 :: f2 :: f3 :: f4 :: f5 :: (if ctr > 1000 then map2_slow ~f tl1 tl2 else count_map2_exn ~f tl1 tl2 (ctr + 1)) | _, _ -> failwith "count_map2" let map2_exn l1 l2 ~f = count_map2_exn ~f l1 l2 0 end end open Internal_pervasives module type NATIVE_CHARACTER = BASIC_CHARACTER with type t = char module type NATIVE_STRING = sig include BASIC_STRING with type t = String.t with type character = char include UNSAFELY_MUTABLE with type t := String.t with type character := char end module Native_character : NATIVE_CHARACTER = struct type t = char let of_native_char x = Some x let of_int x = try Some (char_of_int x) with _ -> None let to_int = int_of_char let compare = Char.compare let size _ = 1 let is_print t = ' ' <= t && t <= '~' let to_native_string x = String.make 1 x let to_string_hum x = if is_print x then String.make 1 x else sprintf "0x%2x" (int_of_char x) let write_to_native_string c ~buf ~index = try buf.[index] <- c; return 1 with _ -> fail `out_of_bounds let read_from_native_string ~buf ~index = try Some (buf.[index], 1) with _ -> None let is_whitespace = function ' ' | '\t' | '\r' | '\n' -> true | _ -> false end module type T_LENGTH_AND_COMPSUB = sig type t val length: t -> int val compare_substring: t * int * int -> t * int * int -> int end (* This functor builds a `compare_substring_strict` function out of a `compare_substring` function. It may not be the optimal algorithm (it may call `length` on both strings.) *) module Compare_substring_strict_of_loose (S: T_LENGTH_AND_COMPSUB) = struct open S let compare_substring_strict (a, idxa, lena) (b, idxb, lenb) = let check_a = lazy (idxa >= 0 && lena >= 0 && idxa + lena <= (length a)) in let check_b = lazy (idxb >= 0 && lenb >= 0 && idxb + lenb <= (length b)) in if lena = 0 && lenb = 0 then Some 0 else (if lena = 0 then (if Lazy.force check_b then Some (-1) else None) else (if lenb = 0 then (if Lazy.force check_a then Some (1) else None) else (if not (Lazy.force check_a) || not (Lazy.force check_b) then None else Some (compare_substring (a, idxa, lena) (b, idxb, lenb))))) end module Make_index_of_string (S: T_LENGTH_AND_COMPSUB) = struct open S let index_of_string ?(from=0) ?(sub_index=0) ?sub_length t ~sub = let module With_exn = struct exception Found of int let f () = (* Readjust the arguments: *) let length_of_t = length t in let from = if from <= 0 then 0 else min length_of_t from in let total_length_of_sub = length sub in let sub_index = if sub_index <= 0 then 0 else sub_index in let sub_length = let default = max 0 (total_length_of_sub - sub_index) in match sub_length with | None -> default | Some s when s >= default -> default | Some s when s < 0 -> 0 | Some s -> s in (* dbg "from: %d, length: %d sub_index: %d sub_length: %d" *) (* from length_of_t sub_index sub_length; *) if from >= length_of_t then None else if length_of_t = 0 then None else if sub_length <= 0 then Some from else begin try for i = 0 to length_of_t - from do if compare_substring (t, i + from, sub_length) (sub, sub_index, sub_length) = 0 then raise (Found (i + from)) done; None with Found f -> Some f end end in With_exn.f () let index_of_string_reverse ?from ?(sub_index=0) ?sub_length t ~sub = let module With_exn = struct exception Found of int let f () = let length_of_t = length t in let last = length_of_t - 1 in let from = match from with | None -> last | Some f when f >= last -> last | Some f -> f in let total_length_of_sub = length sub in let sub_index = if sub_index <= 0 then 0 else sub_index in let sub_length = let default = max 0 (total_length_of_sub - sub_index) in match sub_length with | None -> default | Some s when s >= default -> default | Some s when s < 0 -> 0 | Some s -> s in (* dbg "from: %d, length: %d sub_index: %d sub_length: %d" *) (* from length_of_t sub_index sub_length; *) if from < 0 then None else if length_of_t = 0 then None else if sub_length <= 0 then Some from else begin try for i = from downto 0 do if compare_substring (t, i, sub_length) (sub, sub_index, sub_length) = 0 then raise (Found (i)) done; None with Found f -> Some f end end in With_exn.f () end (* This module type is a subset of `BASIC_STRING` for strings with a `length` function, a `sub_exn` function, and the `index_of_*` functions *) module type T_LENGTH_SUB_AND_SEARCH = sig type t type character val length: t -> int val sub_exn: t -> index:int -> length:int -> t val index_of_character: t -> ?from:int -> character -> int option val index_of_string: ?from:int -> ?sub_index:int -> ?sub_length:int -> t -> sub:t -> int option end (* This functor implements the `BASIC_STRING.split` function out of a `T_LENGTH_AND_SEARCH` *) module Make_split_function (S: T_LENGTH_SUB_AND_SEARCH) = struct let split t ~on = let length_of_t = S.length t in begin match on with | `Character c -> let rec loop acc from = match S.index_of_character t ~from c with | Some index -> loop (S.sub_exn t ~index:from ~length:(index - from) :: acc) (index + 1) | None -> (S.sub_exn t ~index:from ~length:(length_of_t - from) :: acc) in List.rev (loop [] 0) | `String s -> let length_of_s = S.length s in let rec loop acc from = match S.index_of_string t ~from ~sub:s with | Some index -> loop (S.sub_exn t ~index:from ~length:(index - from) :: acc) (index + length_of_s) | None -> (S.sub_exn t ~index:from ~length:(length_of_t - from) :: acc) in if length_of_s > 0 then List.rev (loop [] 0) else if length_of_t = 0 then [ t ] else begin let res = ref [] in for index = length_of_t - 1 downto 0 do res := S.sub_exn t ~index ~length:1 :: !res done; !res end end end module Make_strip_function (S: sig type t type character val empty : t val is_whitespace: character -> bool val length: t -> int val find: ?from:int -> ?length:int -> t -> f:(character -> bool) -> int option val find_reverse: ?from:int -> ?length:int -> t -> f:(character -> bool) -> int option val sub_exn: t -> index:int -> length:int -> t end) = struct let strip ?(on=`Both) ?(whitespace=S.is_whitespace) t = let open S in let first_non () = match find t ~f:(fun c -> not (whitespace c)) with | None -> raise Not_found | Some s -> s in let last_non () = match find_reverse t ~f:(fun c -> not (whitespace c)) with | None -> raise Not_found | Some s -> s in try match on with | `Both -> let index = first_non () in let last = last_non () in sub_exn t ~index ~length:(last - index + 1) | `Left -> let index = first_non () in sub_exn t ~index ~length:(length t - index) | `Right -> let last = last_non () in sub_exn t ~index:0 ~length:(last + 1) with | Not_found -> empty end module Make_prefix_suffix_array (A: sig type t type character val get : t -> int -> character val length: t -> int val sub_exn: t -> index:int -> length:int -> t end) = struct let rec sub_same_tl t ~comp ~len ~off = let rec loop i = i = len || (A.get t (off + i) = A.get comp i) && loop (i + 1) in (A.length t >= len) && loop 0 let is_prefix t ~prefix = let len = A.length prefix in sub_same_tl t ~comp:prefix ~len ~off:0 let is_suffix t ~suffix = let len = A.length suffix and lt = A.length t in sub_same_tl t ~comp:suffix ~len ~off:(lt - len) let chop_prefix_exn t ~prefix = let len = A.length prefix and lt = A.length t in if sub_same_tl t ~comp:prefix ~len ~off:0 then A.sub_exn t ~index:len ~length:(lt - len) else raise (Invalid_argument "not a prefix") let chop_prefix t ~prefix = try Some (chop_prefix_exn t prefix) with _ -> None let chop_suffix_exn t ~suffix = let len = A.length suffix and lt = A.length t in if sub_same_tl t ~comp:suffix ~len ~off:(lt - len) then A.sub_exn t ~index:0 ~length:(lt - len) else raise (Invalid_argument "not a suffix") let chop_suffix t ~suffix = try Some (chop_suffix_exn t suffix) with _ -> None end module Make_split_at_index_functions (A: sig type t type character val empty : t val length : t -> int val sub_exn : t -> index:int -> length:int -> t end) = struct let split_at t ~index = let l = A.length t in if index < 0 then (A.empty, t) else if index >= l then (t, A.empty) else (A.sub_exn t ~index:0 ~length:index), (A.sub_exn t ~index:index ~length:(l - index)) let take t ~index = let l = A.length t in if index < 0 then A.empty else if index >= l then t else A.sub_exn t ~index:0 ~length:index let drop t ~index = let l = A.length t in if index < 0 then t else if index >= l then A.empty else (A.sub_exn t ~index:index ~length:(l - index)) end module Native_string : NATIVE_STRING = struct include StringLabels type character = char let empty = "" let is_empty t = (compare "" t = 0) let of_character = String.make 1 let of_character_list cl = let length = List.length cl in let buf = String.make length '\x00' in List.iteri cl ~f:(fun i c -> buf.[i] <- c); buf let to_character_list s = let res = ref [] in for i = length s - 1 downto 0 do res := s.[i] :: !res done; !res let get s ~index = try Some (s.[index]) with _ -> None let set s ~index ~v = if index > String.length s - 1 then None else begin let cop = String.copy s in cop.[index] <- v; Some cop end let get_exn s ~index = s.[index] let set_exn s ~index ~v = match set s ~index ~v with None -> failwith "set_exn" | Some s -> s let compare_substring (a, idxa, lena) (b, idxb, lenb) = let module With_exns = struct exception Return of int exception Left_out of int exception Right_out of int let f () = try let shortest = min lena lenb in for i = 0 to shortest - 1 do let ca = try a.[idxa + i] with _ -> raise (Left_out i) in let cb = try b.[idxb + i] with _ -> raise (Right_out i) in let c = Char.compare ca cb in if c <> 0 then raise (Return c) else () done; (Pervasives.compare (lena : int) lenb) with | Return c -> c | Left_out c -> (* a went out of bounds at 'c + idxa' *) -1 | Right_out _ -> (* b went out of bounds at 'c + idxb' *) (* so, a is “longer” *) 1 end in With_exns.f () type s = t module T_length_and_compsub = struct type t = s let length = length let compare_substring = compare_substring end include Compare_substring_strict_of_loose(T_length_and_compsub) include Make_index_of_string(T_length_and_compsub) let to_native_string x = String.copy x let of_native_string x = return (String.copy x) let of_native_substring x ~offset ~length = if length = 0 then return "" else try return (String.sub x offset length) with e -> fail `out_of_bounds let to_string_hum x = sprintf "%S" x let concat ?(sep="") sl = concat ~sep sl let fold t ~init ~f = let res = ref init in for i = 0 to String.length t - 1 do res := f !res t.[i]; done; !res let foldi t ~init ~f = let res = ref init in for i = 0 to String.length t - 1 do res := f i !res t.[i]; done; !res let fold2_exn t1 t2 ~init ~f = let lgth1 = (length t1) in let lgth2 = (length t2) in match lgth1, lgth2 with | 0, 0 -> init | _, _ when lgth1 <> lgth2 -> failwith "fold2_exn" | lgth1, lgth2 -> let res = ref init in for i = 0 to lgth1 - 1 do res := f !res t1.[i] t2.[i]; done; !res let sub_exn t ~index ~length = if length = 0 then empty else String.sub t index length let sub t ~index ~length = if length = 0 then Some empty else try Some (String.sub t index length) with e -> None let slice_exn ?(start=0) ?finish t = let length_of_t = String.length t in let bound_check strict m x = let out_of_ub = if strict then x > length_of_t else x >= length_of_t in if x < 0 || (not (is_empty t) && out_of_ub) then ksprintf failwith "slice_exn: invalid %s %d" m x else x in let _ = bound_check false "start" start and finish = match finish with | None -> length_of_t | Some f -> bound_check true "finish" f in sub_exn t ~index:start ~length:(finish - start) let slice ?start ?finish t = try Some (slice_exn ?start ?finish t) with _ -> None let mutate_exn t ~index c = String.set t index c let mutate t ~index c = try String.set t index c; return () with _ -> fail `out_of_bounds let blit_exn ~src ~src_index ~dst ~dst_index ~length = blit ~src ~src_pos:src_index ~dst ~dst_pos:dst_index ~len:length let blit ~src ~src_index ~dst ~dst_index ~length = try blit_exn ~src ~src_index ~dst ~dst_index ~length; return () with _ -> fail `out_of_bounds let iter t ~f = String.iter t ~f let iteri t ~f = String.iteri t ~f let iter_reverse t ~f = for i = length t -1 downto 0 do f (get_exn t i) done let rev t = let lgth = length t in match lgth with | 0 -> empty | lgth -> let res = make lgth (String.get t 0) in for i = 0 to lgth - 1 do String.set res i (String.get t (lgth - 1 - i)) done; res let map t ~f = String.map t ~f let map2_exn t1 t2 ~f = let lgth1 = (length t1) in let lgth2 = (length t2) in match lgth1, lgth2 with | 0, 0 -> empty | _, _ when lgth1 <> lgth2 -> failwith "map2_exn" | lgth1, lgth2 -> let res = make lgth1 (String.get t1 0) in for i = 0 to lgth1 - 1 do String.set res i (f (String.get t1 i) (String.get t2 i)) done; res let mapi t ~f = let buffer = String.create (String.length t) in let () = String.iteri t ~f:(fun i c -> String.set buffer i (f i c)) in buffer (* TODO: Change this to let mapi t ~f = String.mapi t ~f once we switch to 4.02 *) let for_all t ~f = try (iter t (fun x -> if not (f x) then raise Not_found else ()); true) with Not_found -> false let exists t ~f = try (iter t (fun x -> if f x then raise Not_found else ()); false) with Not_found -> true let index_of_character t ?(from=0) c = let from = if from <= 0 then 0 else min (length t) from in try Some (String.index_from t from c) with _ -> None let index_of_character_reverse t ?from c = let from = let length_of_t = length t in match from with | None -> length_of_t - 1 | Some s when s < 0 -> -1 | Some s when s > length_of_t - 1 -> length_of_t - 1 | Some s -> s in try Some (String.rindex_from t from c) with _ -> None let resize_from_length ~from ?length ~length_of_s = let from = if from <= 0 then 0 else min length_of_s from in let length = match length with | None -> length_of_s - from | Some lg when lg <= 0 -> 0 | Some lg -> min (length_of_s - from) lg in (from, length) let find ?(from=0) ?length s ~f = let length_of_s = String.length s in let from, length = resize_from_length ~from ?length ~length_of_s in let found = ref None in let i = ref 0 in while !found = None && !i < length do if f (get_exn s (!i + from)) then found := Some (!i + from) else incr i done; !found let find_reverse ?from ?length s ~f = let length_of_s = String.length s in if length_of_s = 0 then None else begin let from = match from with | None -> length_of_s - 1 | Some s when s < 0 -> -1 | Some s when s >= length_of_s - 1 -> length_of_s - 1 | Some s -> s in let length = match length with | None -> from + 1 | Some l when l <= 0 -> 0 | Some l when l >= from + 1 -> from + 1 | Some l -> l in let found = ref None in let i = ref from in while !found = None && !i >= from - length + 1 do (* dbg "i: %d from: %d length: %d" !i from length; *) if f (get_exn s !i) then found := Some (!i) else decr i done; !found end let filter_map ?(from=0) ?length s ~f = let length_of_s = String.length s in let from, length = resize_from_length ~from ?length ~length_of_s in if length = 0 then empty else begin let b = Buffer.create length in for i = 0 to length - 1 do match f (get_exn s (i + from)) with | Some c -> Buffer.add_char b c | None -> () done; Buffer.contents b end let filter ?from ?length s ~f = filter_map ?from ?length s ~f:(fun c -> if f c then Some c else None) include Make_strip_function (struct type t = string type character = char let empty = empty let length = length let sub_exn = sub_exn let find = find let find_reverse = find_reverse let is_whitespace = Native_character.is_whitespace end) include Make_split_function(struct type t = string type character = char let length = length let sub_exn = sub_exn let index_of_string = index_of_string let index_of_character = index_of_character end) include Make_prefix_suffix_array (struct type t = string type character = char let length = length let get = (fun s i -> s.[i]) let sub_exn = sub_exn end) include Make_split_at_index_functions(struct type t = string type character = char let empty = empty let length = length let sub_exn = sub_exn end) module Make_output (Model: OUTPUT_MODEL) = Model let take_while_with_index t ~f = let buf = Buffer.create (length t) in let rec loop idx = match get t idx with | Some c when f idx c -> Buffer.add_char buf c; loop (idx + 1) | _ -> () in loop 0; Buffer.contents buf let take_while t ~f = take_while_with_index t ~f:(fun _ c -> f c) end (* Module to help build `{of,to}_native_[sub]string` functions. It is most useful while using variable sized characters. *) module Make_native_conversions = struct let of_native_substring ~empty ~init ~on_new_character ~finalize ~read_character_from_native_string s ~offset ~length = if length = 0 then return empty else begin (if offset + length > String.length s then fail `out_of_bounds else return ()) >>= fun () -> let module With_exn = struct exception WChar of int let f buf = let x = init () in try let rec loop index = if index < offset + length then begin match read_character_from_native_string ~buf ~index with | Some (s, size) when index + size <= offset + length -> on_new_character x s; loop (index + size) | Some (_, _ (* too big size *)) | None -> raise (WChar index) end else () in loop offset; return (finalize x) with | WChar c -> fail (`wrong_char_at c) end in With_exn.f s end let of_native_string of_native_substring s = match of_native_substring s ~offset:0 ~length:(String.length s) with | `Ok o -> return o | `Error (`wrong_char_at c) -> fail (`wrong_char_at c) | `Error `out_of_bounds -> (* There is a bug ! *) assert false let to_native_string_knowing_size ~future_size ~iter ~write_char_to_native_string l = let length = future_size l in let buf = String.make length 'B' in let index = ref 0 in iter l ~f:begin fun c -> match write_char_to_native_string c ~buf ~index:!index with | `Ok siz -> index := !index + siz | `Error `out_of_bounds -> failwith "Bug in Make_native_conversions.to_native_string" end; buf end module List_of (Char: BASIC_CHARACTER) : BASIC_STRING with type character = Char.t with type t = Char.t list = struct type character = Char.t type t = character list let empty = [] let is_empty = (=) [] let make length c = let rec loop n acc = if n >= length then acc else loop (n + 1) (c :: acc) in loop 0 [] let of_character c = [c] let of_character_list cl = cl let to_character_list cl = cl let get sl ~index = try Some (List.nth sl index) with _ -> None let set s ~index ~v = let rec loop n acc = function | [] -> None | q :: t when n = index -> Some (List.rev_append acc (v :: t)) | q :: t -> loop (n + 1) (q :: acc) t in loop 0 [] s let get_exn s ~index = match get s ~index with None -> failwith "get_exn" | Some s -> s let set_exn s ~index ~v = match set s ~index ~v with None -> failwith "set_exn" | Some s -> s let iter t ~f = List.iter t ~f let iteri t ~f = List.iteri t ~f let iter_reverse t ~f = List.iter (List.rev t) ~f let rev t = List.rev t let fold t ~init ~f = List.fold_left t ~init ~f let foldi t ~init ~f = snd (List.fold_left t ~init:(0,init) ~f:(fun (i,a) c -> (i+1,f i a c))) let fold2_exn t1 t2 ~init ~f = List.fold_left2 t1 t2 ~init ~f let map = Core_list_map.map let mapi = Core_list_map.mapi let map2_exn = Core_list_map.map2_exn let for_all t ~f = List.for_all t ~f let exists t ~f = List.exists t ~f let compare (a : Char.t list) (b: Char.t list) = compare a b let of_native_substring s ~offset ~length = Make_native_conversions.of_native_substring ~empty ~init:(fun () -> ref []) ~on_new_character:(fun x c -> x := c :: !x) ~finalize:(fun x -> List.rev !x) ~read_character_from_native_string:Char.read_from_native_string s ~offset ~length let of_native_string s = Make_native_conversions.of_native_string of_native_substring s let to_native_string l = Make_native_conversions.to_native_string_knowing_size ~future_size:(fun l -> List.fold_left l ~init:0 ~f:(fun sum c -> sum + Char.size c)) ~iter ~write_char_to_native_string:Char.write_to_native_string l let to_string_hum l = sprintf "%S" (to_native_string l) let concat ?(sep=[]) ll = match ll with | [] -> [] | hh :: tt -> let x = ref (List.rev hh) in List.iter tt ~f:(fun l -> x := List.rev_append sep !x; x := List.rev_append l !x; ); List.rev !x let length = List.length let sub t ~index ~length = let r = ref [] in let c = ref 0 in try List.iteri t ~f:(fun i a -> if i >= index + length then raise Not_found; if index <= i then ( r:= a :: !r; incr c; ); ); if !c = length then Some (List.rev !r) else None with | Not_found -> Some (List.rev !r) let sub_exn t ~index ~length = match sub t ~index ~length with | Some s -> s | None -> ksprintf failwith "sub_exn(%d,%d)" index length let slice_exn ?(start=0) ?finish t = let length_of_t = List.length t in if start < 0 || (not (is_empty t) && start >= length_of_t) then ksprintf failwith "slice_exn: invalid start %d" start else match finish with | None -> sub_exn t ~index:start ~length:(length_of_t - start) | Some f -> if f < 0 || f > length_of_t then ksprintf failwith "slice_exn: invalid finish %d" f else sub_exn t ~index:start ~length:(f - start) let slice ?start ?finish t = try Some (slice_exn ?start ?finish t) with _ -> None let rec comp_loop p lst_pair = if p then match lst_pair with | (i,[]) -> Some i | ([],j) -> None | (i::is), (j::js) -> comp_loop (i = j) (is,js) else None let is_prefix t ~prefix = match comp_loop true (t,prefix) with | Some _ -> true | None -> false let is_suffix t ~suffix = is_prefix (List.rev t) ~prefix:(List.rev suffix) let chop_prefix_exn t ~prefix = match comp_loop true (t,prefix) with | Some r -> r | None -> raise (Invalid_argument "chop_prefix_exn: not a prefix") let chop_prefix t ~prefix = try Some (chop_prefix_exn t prefix) with _ -> None let chop_suffix_exn t ~suffix = List.rev (chop_prefix_exn (List.rev t) ~prefix:(List.rev suffix)) let chop_suffix t ~suffix = try Some (chop_suffix_exn t suffix) with _ -> None let unrevSplit t n = if n < 0 then [],t else let rec offset i ((l,r) as p) = if i = n then p else match r with | [] -> p | h::t -> offset (i + 1) (h::l,t) in offset 0 ([],t) let split_at t ~index = let l,r = unrevSplit t index in List.rev l, r let take t ~index = fst (split_at t index) let drop t ~index = let l,r = unrevSplit t index in r let index_of_character t ?(from=0) c = let index = ref 0 in try begin List.iter t ~f:(fun x -> if !index >= from then if x = c then failwith "found" else incr index else incr index); None end with _ -> Some !index let index_of_character_reverse t ?from c = let length_of_t, rev = let rec loop lgth acc = function | [] -> (lgth, acc) | h :: t -> loop (lgth + 1) (h :: acc) t in loop 0 [] t in let from = match from with | None -> length_of_t - 1 | Some s when s < 0 -> -1 | Some s when s > length_of_t - 1 -> length_of_t - 1 | Some s -> s in match index_of_character rev ~from:(length_of_t - from - 1) c with | Some c -> Some (length_of_t - c - 1) | None -> None let compare_substring (a, idxa, lena) (b, idxb, lenb) = let module With_exns = struct exception Left exception Right let rec drop_until ~exn idx l = match idx, l with | 0, l -> l | more, [] -> raise exn | more, h :: t -> drop_until ~exn (more - 1) t let f () = begin try let rec cmp l1 l2 len1 len2 = if len1 < 0 then raise Left; if len2 < 0 then raise Right; match l1, l2 with | _, _ when len1 = 0 && len2 = 0 -> 0 | _, _ when len1 = 0 -> -1 | _, _ when len2 = 0 -> 1 | [], [] when len1 = 0 || len2 = 0 -> Pervasives.compare lena lenb | [], _ when len1 > 0 -> raise Left | _, [] when len2 > 0 -> raise Right | h1 :: t1, h2 :: t2 when Char.compare h1 h2 = 0 -> cmp t1 t2 (len1 - 1) (len2 - 1) | h1 :: _, h2 :: _ -> Char.compare h1 h2 | _, _ -> assert false (* calming down the warnings.. *) in if lena = 0 && lenb = 0 then 0 else ( let aa = drop_until ~exn:Left idxa a in let bb = drop_until ~exn:Right idxb b in (cmp aa bb lena lenb) ) with | Left -> -1 | Right -> 1 | Failure s -> 1 (* dbg "(%d, %d/%d) Vs (%d, %d/%d) %s" idxa lena (length a) idxb lenb (length b) s; *) end end in With_exns.f () type s = t module T_length_and_compsub = struct type t = s let length = length let compare_substring = compare_substring end include Compare_substring_strict_of_loose(T_length_and_compsub) include Make_index_of_string(T_length_and_compsub) let find ?(from=0) ?length s ~f = (* index and virtual_length are maybe a bit redundant but I favor readability of the branches of the match *) let from = if from <= 0 then 0 else from in let rec find_from index virtual_length l = match l, length with | [], _ -> None | _, Some lgth when lgth <= virtual_length -> None | h :: t, _ when index < from -> find_from (index + 1) virtual_length t | h :: t, _ when index >= from && f h -> Some index | h :: t, _ -> find_from (index + 1) (virtual_length + 1) t in find_from 0 0 s let find_reverse ?from ?length s ~f = let length_of_s = List.length s in let from = match from with | None -> None | Some s when s < 0 -> Some length_of_s | Some s when s > length_of_s - 1 -> Some 0 | Some s -> Some (length_of_s - 1 - s) in match find ?from ?length (List.rev s) ~f with | None -> None | Some i -> Some (length_of_s - 1 - i) let filter_map ?(from=0) ?length t ~f = let rec filter_map_rec acc index virtual_length l = match l, length with | [], _ -> List.rev acc | _, Some lgth when lgth <= virtual_length -> List.rev acc | h :: t, _ when index < from -> filter_map_rec acc (index + 1) virtual_length t | h :: t, _ (* when index >= from *) -> begin match f h with | Some o -> filter_map_rec (o :: acc) (index + 1) (virtual_length + 1) t | None -> filter_map_rec acc (index + 1) (virtual_length + 1) t end in filter_map_rec [] 0 0 t let filter ?from ?length t ~f = filter_map ?from ?length t ~f:(fun c -> if f c then Some c else None) include Make_strip_function (struct type t = Char.t list type character = Char.t let empty = empty let length = length let sub_exn = sub_exn let find = find let find_reverse = find_reverse let is_whitespace = Char.is_whitespace end) include Make_split_function(struct type t = Char.t list type character = Char.t let length = length let sub_exn = sub_exn let index_of_string = index_of_string let index_of_character = index_of_character end) module Make_output (Model: OUTPUT_MODEL) = struct let (>>=) = Model.bind let output chan l = List.fold_left l ~init:(Model.return ()) ~f:(fun prev_m c -> prev_m >>= fun () -> Model.output chan (Char.to_native_string c)) end let take_while_with_index t ~f = let rec loop idx acc = function | h :: t when f idx h -> loop (idx + 1) (h :: acc) t | [] | _ :: _ -> List.rev acc in loop 0 [] t let take_while t ~f = take_while_with_index t ~f:(fun _ c -> f c) end module Int_utf8_character : BASIC_CHARACTER with type t = int = struct type t = int let of_native_char x = Some (int_of_char x) let compare (i: int) (j : int) = compare i j let of_int x = if x land 0x7FFF_FFFF = x then Some x else None let to_int c = c let size x = if x <= 0x7f then 1 else if x <= 0x7ff then 2 else if x <= 0xffff then 3 else if x <= 0x1f_ffff then 4 else if x <= 0x3ff_ffff then 5 else if x <= 0x7fff_ffff then 6 else 0 let is_print t = int_of_char ' ' <= t && t <= int_of_char '~' let to_string_hum x = if is_print x then String.make 1 (char_of_int x) else sprintf "&#x%X;" x let write_to_native_string c ~buf ~index = let sz = size c in try let first_byte = match sz with | 1 -> ((c lsr 0) land 0b0111_1111) lor 0b0000_0000 | 2 -> ((c lsr 6) land 0b0001_1111) lor 0b1100_0000 | 3 -> ((c lsr 12) land 0b0000_1111) lor 0b1110_0000 | 4 -> ((c lsr 18) land 0b0000_0111) lor 0b1111_0000 | 5 -> ((c lsr 24) land 0b0000_0011) lor 0b1111_1000 | 6 -> ((c lsr 30) land 0b0000_0001) lor 0b1111_1100 | _ -> assert false in buf.[index] <- char_of_int first_byte; for i = 2 to sz do let ith_byte = ((c lsr (6 * (i - 2))) land 0b0011_1111) lor 0b1000_0000 in buf.[index + sz - i + 1] <- char_of_int ith_byte; done; return sz with _ -> fail `out_of_bounds let read_from_native_string ~buf ~index = try let first_char = buf.[index] |> int_of_char in let size, mask = if first_char lsr 7 = 0 then (1, 0b0111_1111) else if first_char lsr 5 = 0b110 then (2, 0b0001_1111) else if first_char lsr 4 = 0b1110 then (3, 0b0000_1111) else if first_char lsr 3 = 0b11110 then (4, 0b0000_0111) else if first_char lsr 2 = 0b111110 then (5, 0b0000_0011) else if first_char lsr 1 = 0b1111110 then (6, 0b0000_0001) else raise Not_found in let the_int = ref (first_char land mask) in for i = 1 to size - 1 do let the_char = buf.[index + i] |> int_of_char in if (the_char lsr 6) = 0b10 then ( the_int := (!the_int lsl 6) lor (the_char land 0b0011_1111); ) else raise Not_found; done; Some (!the_int, size) with _ -> None let to_native_string x = let buf = String.make (size x) 'B' in begin match write_to_native_string x ~buf ~index:0 with | `Ok _ -> () | `Error e -> dbg "buf: %S siz: %d x: %d" buf (size x) x; assert false end; buf let is_whitespace c = try match char_of_int c with | ' ' | '\t' | '\r' | '\n' -> true | _ -> false with _ -> false end module type MINIMALISTIC_MUTABLE_STRING = sig type character type t val empty: t val make: int -> character -> t val length: t -> int val compare: t -> t -> int val compare_char: character -> character -> int val get: t -> int -> character val set: t -> int -> character -> unit val blit: src:t -> src_pos:int -> dst:t -> dst_pos:int -> len:int -> unit val is_whitespace: character -> bool include NATIVE_CONVERSIONS with type t := t end module Of_mutable (S: MINIMALISTIC_MUTABLE_STRING) : BASIC_STRING with type character = S.character with type t = S.t = struct include S let is_empty s = try ignore (S.get s 0); false with _ -> true let get t ~index = try Some (get t index) with _ -> None let set t ~index ~v:c = let lgth = length t in if index < 0 || lgth <= index then None else Some ( let res = make lgth (S.get t 0) in blit ~dst:res ~dst_pos:0 ~src:t ~src_pos:0 ~len:lgth; S.set res index c; res) let get_exn s ~index = S.get s index let set_exn s ~index ~v = match set s ~index ~v with None -> failwith "set_exn" | Some s -> s let of_character c = make 1 c let of_character_list cl = match cl with | [] -> empty | one :: more -> let res = make (List.length cl) one in List.iteri more ~f:(fun i c -> S.set res (i + 1) c); res let to_character_list s = let res = ref [] in for i = S.length s - 1 downto 0 do res := S.get s i :: !res done; !res let rec concat ?(sep=empty) tl = match tl with | [] -> empty | one :: more -> begin try let first_char = try S.get one 0 with _ -> S.get sep 0 in let sep_length = S.length sep in let total_length = List.fold_left ~init:(S.length one) more ~f:(fun prev s -> prev + sep_length + S.length s) in let dst = make total_length first_char in let index = ref 0 in blit ~dst ~dst_pos:!index ~src:one ~src_pos:0 ~len:(length one); index := !index + (length one); List.iter more ~f:(fun s -> blit ~dst ~dst_pos:!index ~src:sep ~src_pos:0 ~len:sep_length; index := !index + sep_length; blit ~dst ~dst_pos:!index ~src:s ~src_pos:0 ~len:(length s); index := !index + (length s); ); dst with _ -> concat more ~sep (* both one and sep are empty *) end let iter t ~f = for i = 0 to length t - 1 do f (S.get t i) done let iteri t ~f = for i = 0 to length t - 1 do f i (S.get t i) done let iter_reverse t ~f = for i = length t -1 downto 0 do f (S.get t i) done let fold t ~init ~f = let x = ref init in for i = 0 to length t - 1 do x := f !x (S.get t i) done; !x let foldi t ~init ~f = let x = ref init in for i = 0 to length t - 1 do x := f i !x (S.get t i) done; !x let fold2_exn t1 t2 ~init ~f = let lgth1 = (length t1) in let lgth2 = (length t2) in match lgth1, lgth2 with | 0, 0 -> init | _, _ when lgth1 <> lgth2 -> failwith "fold2_exn" | lgth1, lgth2 -> let res = ref init in for i = 0 to lgth1 - 1 do res := f !res (S.get t1 i) (S.get t2 i); done; !res let rev t = let lgth = length t in match lgth with | 0 -> empty | lgth -> let res = make lgth (S.get t 0) in for i = 0 to lgth - 1 do S.set res i (S.get t (lgth - 1 - i)) done; res let map t ~f = let lgth = (length t) in if lgth = 0 then empty else begin let res = make lgth (S.get t 0) in for i = 0 to lgth - 1 do S.set res i (f (S.get t i)) done; res end let mapi t ~f = let lgth = (length t) in if lgth = 0 then empty else begin let res = make lgth (S.get t 0) in for i = 0 to lgth - 1 do S.set res i (f i (S.get t i)) done; res end let map2_exn t1 t2 ~f = let lgth1 = (length t1) in let lgth2 = (length t2) in match lgth1, lgth2 with | 0, 0 -> empty | _, _ when lgth1 <> lgth2 -> failwith "map2_exn" | lgth1, lgth2 -> let res = make lgth1 (S.get t1 0) in for i = 0 to lgth1 - 1 do S.set res i (f (S.get t1 i) (S.get t2 i)) done; res let for_all t ~f = try iter t (fun c -> if not (f c) then raise Not_found); true with _ -> false let exists t ~f = try iter t (fun c -> if (f c) then raise Not_found); false with _ -> true let sub t ~index ~length = if length = 0 then Some empty else begin let lgth = S.length t in if lgth = 0 then None (* `length <> 0` *) else begin try let res = make length (S.get t index) in for i = 1 to length - 1 do S.set res i (S.get t (index + i)) done; Some res with _ -> None end end let sub_exn t ~index ~length = match sub t ~index ~length with | Some s -> s | None -> ksprintf failwith "sub_exn(%d,%d)" index length let slice_exn ?(start=0) ?finish t = let length_of_t = S.length t in if start < 0 || (not (is_empty t) && start >= length_of_t) then ksprintf failwith "slice_exn: invalid start %d" start else match finish with | None -> sub_exn t ~index:start ~length:(length_of_t - start) | Some f -> if f < 0 || f > length_of_t then ksprintf failwith "slice_exn: invalid finish %d" f else sub_exn t ~index:start ~length:(f - start) let slice ?start ?finish t = try Some (slice_exn ?start ?finish t) with _ -> None let to_string_hum t = to_native_string t |> sprintf "%S" let index_of_character t ?(from=0) c = let from = if from <= 0 then 0 else min (length t) from in let res = ref None in try for i = from to length t - 1 do if S.get t i = c then (res:= Some i; raise Not_found) done; None with _ -> !res let index_of_character_reverse t ?from c = let from = let length_of_t = length t in match from with | None -> length_of_t - 1 | Some s when s < 0 -> -1 | Some s when s > length_of_t - 1 -> length_of_t - 1 | Some s -> s in let res = ref None in try for i = from downto 0 do if S.get t i = c then (res:= Some i; raise Not_found) done; None with _ -> !res let compare_substring (a, idxa, lena) (b, idxb, lenb) = let module With_exns = struct exception Return of int exception Left_out of int exception Right_out of int let f () = try let shortest = min lena lenb in for i = 0 to shortest - 1 do let ca = try S.get a (idxa + i) with _ -> raise (Left_out i) in let cb = try S.get b (idxb + i) with _ -> raise (Right_out i) in let c = S.compare_char ca cb in if c <> 0 then raise (Return c) else () done; (Pervasives.compare (lena : int) lenb) with | Return c -> c | Left_out c -> (* a went out of bounds at 'c + idxa' *) -1 | Right_out _ -> (* b went out of bounds at 'c + idxb' *) (* so, a is “longer” *) 1 end in With_exns.f () type s = t module T_length_and_compsub = struct type t = s let length = length let compare_substring = compare_substring end include Compare_substring_strict_of_loose(T_length_and_compsub) include Make_index_of_string(T_length_and_compsub) let resize_from_length ~from ?length ~length_of_s = let from = if from <= 0 then 0 else min length_of_s from in let length = match length with | None -> length_of_s - from | Some lg when lg <= 0 -> 0 | Some lg -> min (length_of_s - from) lg in (from, length) let find ?(from=0) ?length s ~f = let length_of_s = S.length s in let from, length = resize_from_length ~from ?length ~length_of_s in let found = ref None in let i = ref 0 in while !found = None && !i < length do if f (get_exn s (!i + from)) then found := Some (!i + from) else incr i done; !found let find_reverse ?from ?length s ~f = let length_of_s = S.length s in if length_of_s = 0 then None else begin let from = match from with | None -> length_of_s - 1 | Some s when s < 0 -> -1 | Some s when s >= length_of_s - 1 -> length_of_s - 1 | Some s -> s in let length = match length with | None -> from + 1 | Some l when l <= 0 -> 0 | Some l when l >= from + 1 -> from + 1 | Some l -> l in let found = ref None in let i = ref from in while !found = None && !i >= from - length + 1 do (* dbg "i: %d from: %d length: %d" !i from length; *) if f (get_exn s !i) then found := Some (!i) else decr i done; !found end let filter_map ?(from=0) ?length s ~f = let length_of_s = S.length s in let from, length = resize_from_length ~from ?length ~length_of_s in if length = 0 then empty else begin let res = ref [] in for i = length - 1 downto 0 do match f (get_exn s (i + from)) with | Some c -> res := c :: !res | None -> () done; of_character_list !res end let filter ?from ?length s ~f = filter_map ?from ?length s ~f:(fun c -> if f c then Some c else None) include Make_strip_function (struct type t = S.t type character = S.character let empty = empty let length = length let sub_exn = sub_exn let find = find let find_reverse = find_reverse let is_whitespace = S.is_whitespace end) include Make_split_function(struct type t = S.t type character = S.character let length = length let sub_exn = sub_exn let index_of_string = index_of_string let index_of_character = index_of_character end) include Make_prefix_suffix_array (struct type t = S.t type character = S.character let length = S.length let get = S.get let sub_exn = sub_exn end) include Make_split_at_index_functions(struct type t = S.t type character = S.character let empty = empty let length = length let sub_exn t ~index ~length = sub_exn t index length end) module Make_output (Model: OUTPUT_MODEL) = struct let (>>=) = Model.bind let output chan t = Model.output chan (to_native_string t) end let take_while_with_index t ~f = if length t = 0 then empty else ( let buf = make (length t) (S.get t 0) in let rec loop idx = match get t idx with | Some c when f idx c -> S.set buf idx c; loop (idx + 1) | _ -> idx in let new_length = loop 0 in sub_exn buf ~index:0 ~length:new_length ) let take_while t ~f = take_while_with_index t ~f:(fun _ c -> f c) end