ocaml/utils/misc.ml

394 lines
12 KiB
OCaml

(***********************************************************************)
(* *)
(* OCaml *)
(* *)
(* Xavier Leroy, projet Cristal, INRIA Rocquencourt *)
(* *)
(* Copyright 1996 Institut National de Recherche en Informatique et *)
(* en Automatique. All rights reserved. This file is distributed *)
(* under the terms of the Q Public License version 1.0. *)
(* *)
(***********************************************************************)
(* Errors *)
exception Fatal_error
let fatal_error msg =
prerr_string ">> Fatal error: "; prerr_endline msg; raise Fatal_error
(* Exceptions *)
let try_finally work cleanup =
let result = (try work () with e -> cleanup (); raise e) in
cleanup ();
result
;;
(* List functions *)
let rec map_end f l1 l2 =
match l1 with
[] -> l2
| hd::tl -> f hd :: map_end f tl l2
let rec map_left_right f = function
[] -> []
| hd::tl -> let res = f hd in res :: map_left_right f tl
let rec for_all2 pred l1 l2 =
match (l1, l2) with
([], []) -> true
| (hd1::tl1, hd2::tl2) -> pred hd1 hd2 && for_all2 pred tl1 tl2
| (_, _) -> false
let rec replicate_list elem n =
if n <= 0 then [] else elem :: replicate_list elem (n-1)
let rec list_remove x = function
[] -> []
| hd :: tl ->
if hd = x then tl else hd :: list_remove x tl
let rec split_last = function
[] -> assert false
| [x] -> ([], x)
| hd :: tl ->
let (lst, last) = split_last tl in
(hd :: lst, last)
let rec samelist pred l1 l2 =
match (l1, l2) with
| ([], []) -> true
| (hd1 :: tl1, hd2 :: tl2) -> pred hd1 hd2 && samelist pred tl1 tl2
| (_, _) -> false
(* Options *)
let may f = function
Some x -> f x
| None -> ()
let may_map f = function
Some x -> Some (f x)
| None -> None
(* File functions *)
let find_in_path path name =
if not (Filename.is_implicit name) then
if Sys.file_exists name then name else raise Not_found
else begin
let rec try_dir = function
[] -> raise Not_found
| dir::rem ->
let fullname = Filename.concat dir name in
if Sys.file_exists fullname then fullname else try_dir rem
in try_dir path
end
let find_in_path_rel path name =
let rec simplify s =
let open Filename in
let base = basename s in
let dir = dirname s in
if dir = s then dir
else if base = current_dir_name then simplify dir
else concat (simplify dir) base
in
let rec try_dir = function
[] -> raise Not_found
| dir::rem ->
let fullname = simplify (Filename.concat dir name) in
if Sys.file_exists fullname then fullname else try_dir rem
in try_dir path
let find_in_path_uncap path name =
let uname = String.uncapitalize_ascii name in
let rec try_dir = function
[] -> raise Not_found
| dir::rem ->
let fullname = Filename.concat dir name
and ufullname = Filename.concat dir uname in
if Sys.file_exists ufullname then ufullname
else if Sys.file_exists fullname then fullname
else try_dir rem
in try_dir path
let remove_file filename =
try
Sys.remove filename
with Sys_error msg ->
()
(* Expand a -I option: if it starts with +, make it relative to the standard
library directory *)
let expand_directory alt s =
if String.length s > 0 && s.[0] = '+'
then Filename.concat alt
(String.sub s 1 (String.length s - 1))
else s
(* Hashtable functions *)
let create_hashtable size init =
let tbl = Hashtbl.create size in
List.iter (fun (key, data) -> Hashtbl.add tbl key data) init;
tbl
(* File copy *)
let copy_file ic oc =
let buff = Bytes.create 0x1000 in
let rec copy () =
let n = input ic buff 0 0x1000 in
if n = 0 then () else (output oc buff 0 n; copy())
in copy()
let copy_file_chunk ic oc len =
let buff = Bytes.create 0x1000 in
let rec copy n =
if n <= 0 then () else begin
let r = input ic buff 0 (min n 0x1000) in
if r = 0 then raise End_of_file else (output oc buff 0 r; copy(n-r))
end
in copy len
let string_of_file ic =
let b = Buffer.create 0x10000 in
let buff = Bytes.create 0x1000 in
let rec copy () =
let n = input ic buff 0 0x1000 in
if n = 0 then Buffer.contents b else
(Buffer.add_subbytes b buff 0 n; copy())
in copy()
(* Integer operations *)
let rec log2 n =
if n <= 1 then 0 else 1 + log2(n asr 1)
let align n a =
if n >= 0 then (n + a - 1) land (-a) else n land (-a)
let no_overflow_add a b = (a lxor b) lor (a lxor (lnot (a+b))) < 0
let no_overflow_sub a b = (a lxor (lnot b)) lor (b lxor (a-b)) < 0
let no_overflow_mul a b = b <> 0 && (a * b) / b = a
let no_overflow_lsl a k = 0 <= k && k < Sys.word_size && min_int asr k <= a && a <= max_int asr k
(* String operations *)
let chop_extension_if_any fname =
try Filename.chop_extension fname with Invalid_argument _ -> fname
let chop_extensions file =
let dirname = Filename.dirname file and basename = Filename.basename file in
try
let pos = String.index basename '.' in
let basename = String.sub basename 0 pos in
if Filename.is_implicit file && dirname = Filename.current_dir_name then
basename
else
Filename.concat dirname basename
with Not_found -> file
let search_substring pat str start =
let rec search i j =
if j >= String.length pat then i
else if i + j >= String.length str then raise Not_found
else if str.[i + j] = pat.[j] then search i (j+1)
else search (i+1) 0
in search start 0
let replace_substring ~before ~after str =
let rec search acc curr =
match search_substring before str curr with
| next ->
let prefix = String.sub str curr (next - curr) in
search (prefix :: acc) (next + String.length before)
| exception Not_found ->
let suffix = String.sub str curr (String.length str - curr) in
List.rev (suffix :: acc)
in String.concat after (search [] 0)
let rev_split_words s =
let rec split1 res i =
if i >= String.length s then res else begin
match s.[i] with
' ' | '\t' | '\r' | '\n' -> split1 res (i+1)
| _ -> split2 res i (i+1)
end
and split2 res i j =
if j >= String.length s then String.sub s i (j-i) :: res else begin
match s.[j] with
' ' | '\t' | '\r' | '\n' -> split1 (String.sub s i (j-i) :: res) (j+1)
| _ -> split2 res i (j+1)
end
in split1 [] 0
let get_ref r =
let v = !r in
r := []; v
let fst3 (x, _, _) = x
let snd3 (_,x,_) = x
let thd3 (_,_,x) = x
let fst4 (x, _, _, _) = x
let snd4 (_,x,_, _) = x
let thd4 (_,_,x,_) = x
let for4 (_,_,_,x) = x
module LongString = struct
type t = bytes array
let create str_size =
let tbl_size = str_size / Sys.max_string_length + 1 in
let tbl = Array.make tbl_size Bytes.empty in
for i = 0 to tbl_size - 2 do
tbl.(i) <- Bytes.create Sys.max_string_length;
done;
tbl.(tbl_size - 1) <- Bytes.create (str_size mod Sys.max_string_length);
tbl
let length tbl =
let tbl_size = Array.length tbl in
Sys.max_string_length * (tbl_size - 1) + Bytes.length tbl.(tbl_size - 1)
let get tbl ind =
Bytes.get tbl.(ind / Sys.max_string_length) (ind mod Sys.max_string_length)
let set tbl ind c =
Bytes.set tbl.(ind / Sys.max_string_length) (ind mod Sys.max_string_length)
c
let blit src srcoff dst dstoff len =
for i = 0 to len - 1 do
set dst (dstoff + i) (get src (srcoff + i))
done
let output oc tbl pos len =
for i = pos to pos + len - 1 do
output_char oc (get tbl i)
done
let unsafe_blit_to_bytes src srcoff dst dstoff len =
for i = 0 to len - 1 do
Bytes.unsafe_set dst (dstoff + i) (get src (srcoff + i))
done
let input_bytes ic len =
let tbl = create len in
Array.iter (fun str -> really_input ic str 0 (Bytes.length str)) tbl;
tbl
end
let edit_distance a b cutoff =
let la, lb = String.length a, String.length b in
let cutoff =
(* using max_int for cutoff would cause overflows in (i + cutoff + 1);
we bring it back to the (max la lb) worstcase *)
min (max la lb) cutoff in
if abs (la - lb) > cutoff then None
else begin
(* initialize with 'cutoff + 1' so that not-yet-written-to cases have
the worst possible cost; this is useful when computing the cost of
a case just at the boundary of the cutoff diagonal. *)
let m = Array.make_matrix (la + 1) (lb + 1) (cutoff + 1) in
m.(0).(0) <- 0;
for i = 1 to la do
m.(i).(0) <- i;
done;
for j = 1 to lb do
m.(0).(j) <- j;
done;
for i = 1 to la do
for j = max 1 (i - cutoff - 1) to min lb (i + cutoff + 1) do
let cost = if a.[i-1] = b.[j-1] then 0 else 1 in
let best =
(* insert, delete or substitute *)
min (1 + min m.(i-1).(j) m.(i).(j-1)) (m.(i-1).(j-1) + cost)
in
let best =
(* swap two adjacent letters; we use "cost" again in case of
a swap between two identical letters; this is slightly
redundant as this is a double-substitution case, but it
was done this way in most online implementations and
imitation has its virtues *)
if not (i > 1 && j > 1 && a.[i-1] = b.[j-2] && a.[i-2] = b.[j-1])
then best
else min best (m.(i-2).(j-2) + cost)
in
m.(i).(j) <- best
done;
done;
let result = m.(la).(lb) in
if result > cutoff
then None
else Some result
end
let spellcheck env name =
let cutoff =
match String.length name with
| 1 | 2 -> 0
| 3 | 4 -> 1
| 5 | 6 -> 2
| _ -> 3
in
let compare target acc head =
match edit_distance target head cutoff with
| None -> acc
| Some dist ->
let (best_choice, best_dist) = acc in
if dist < best_dist then ([head], dist)
else if dist = best_dist then (head :: best_choice, dist)
else acc
in
fst (List.fold_left (compare name) ([], max_int) env)
let did_you_mean ppf get_choices =
(* flush now to get the error report early, in the (unheard of) case
where the search in the get_choices function would take a bit of
time; in the worst case, the user has seen the error, she can
interrupt the process before the spell-checking terminates. *)
Format.fprintf ppf "@?";
match get_choices () with
| [] -> ()
| choices ->
let rest, last = split_last choices in
Format.fprintf ppf "@\nHint: Did you mean %s%s%s?"
(String.concat ", " rest)
(if rest = [] then "" else " or ")
last
(* split a string [s] at every char [c], and return the list of sub-strings *)
let split s c =
let len = String.length s in
let rec iter pos to_rev =
if pos = len then List.rev ("" :: to_rev) else
match try
Some ( String.index_from s pos c )
with Not_found -> None
with
Some pos2 ->
if pos2 = pos then iter (pos+1) ("" :: to_rev) else
iter (pos2+1) ((String.sub s pos (pos2-pos)) :: to_rev)
| None -> List.rev ( String.sub s pos (len-pos) :: to_rev )
in
iter 0 []
let cut_at s c =
let pos = String.index s c in
String.sub s 0 pos, String.sub s (pos+1) (String.length s - pos - 1)
module StringSet = Set.Make(struct type t = string let compare = compare end)
module StringMap = Map.Make(struct type t = string let compare = compare end)