1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388
(************************************************************************) (* * The Coq Proof Assistant / The Coq Development Team *) (* v * INRIA, CNRS and contributors - Copyright 1999-2019 *) (* <O___,, * (see CREDITS file for the list of authors) *) (* \VV/ **************************************************************) (* // * This file is distributed under the terms of the *) (* * GNU Lesser General Public License Version 2.1 *) (* * (see LICENSE file for the text of the license) *) (************************************************************************) (** Unicode utilities *) type status = Letter | IdentPart | Symbol | IdentSep | Unknown (* The following table stores classes of Unicode characters that are used by the lexer. There are 5 different classes so 3 bits are allocated for each character. We encode the masks of 8 characters per word, thus using 24 bits over the 31 available bits. (This choice seems to be a good trade-off between speed and space after some benchmarks.) *) (* A 256 KiB table, initially filled with zeros. *) let table = Array.make (1 lsl 17) 0 (* Associate a 2-bit pattern to each status at position [i]. Only the 3 lowest bits of [i] are taken into account to define the position of the pattern in the word. Notice that pattern "00" means "undefined". *) let mask i = function | Letter -> 1 lsl ((i land 7) * 3) (* 001 *) | IdentPart -> 2 lsl ((i land 7) * 3) (* 010 *) | Symbol -> 3 lsl ((i land 7) * 3) (* 011 *) | IdentSep -> 4 lsl ((i land 7) * 3) (* 100 *) | Unknown -> 0 lsl ((i land 7) * 3) (* 000 *) (* Helper to reset 3 bits in a word. *) let reset_mask i = lnot (7 lsl ((i land 7) * 3)) (* Initialize the lookup table from a list of segments, assigning a status to every character of each segment. The order of these assignments is relevant: it is possible to assign status [s] to a segment [(c1, c2)] and later assign [s'] to [c] even if [c] is between [c1] and [c2]. *) let mk_lookup_table_from_unicode_tables_for status tables = List.iter (List.iter (fun (c1, c2) -> for i = c1 to c2 do table.(i lsr 3) <- (table.(i lsr 3) land (reset_mask i)) lor (mask i status) done)) tables (* Look up into the table and interpret the found pattern. *) let lookup x = let v = (table.(x lsr 3) lsr ((x land 7) * 3)) land 7 in if v = 1 then Letter else if v = 2 then IdentPart else if v = 3 then Symbol else if v = 4 then IdentSep else Unknown (* [classify] discriminates between 5 different kinds of symbols based on the standard unicode classification (extracted from Camomile). *) let classify = let single c = [ (c, c) ] in (* General tables. *) mk_lookup_table_from_unicode_tables_for Symbol [ Unicodetable.sm; (* Symbol, maths. *) Unicodetable.sc; (* Symbol, currency. *) Unicodetable.so; (* Symbol, modifier. *) Unicodetable.pd; (* Punctuation, dash. *) Unicodetable.pc; (* Punctuation, connector. *) Unicodetable.pe; (* Punctuation, open. *) Unicodetable.ps; (* Punctution, close. *) Unicodetable.pi; (* Punctuation, initial quote. *) Unicodetable.pf; (* Punctuation, final quote. *) Unicodetable.po; (* Punctuation, other. *) ]; mk_lookup_table_from_unicode_tables_for Letter [ Unicodetable.lu; (* Letter, uppercase. *) Unicodetable.ll; (* Letter, lowercase. *) Unicodetable.lt; (* Letter, titlecase. *) Unicodetable.lo; (* Letter, others. *) Unicodetable.lm; (* Letter, modifier. *) ]; mk_lookup_table_from_unicode_tables_for IdentPart [ Unicodetable.nd; (* Number, decimal digits. *) Unicodetable.nl; (* Number, letter. *) Unicodetable.no; (* Number, other. *) ]; (* Workaround. Some characters seems to be missing in Camomile's category tables. We add them manually. *) mk_lookup_table_from_unicode_tables_for Letter [ [(0x01D00, 0x01D7F)]; (* Phonetic Extensions. *) [(0x01D80, 0x01DBF)]; (* Phonetic Extensions Suppl. *) [(0x01DC0, 0x01DFF)]; (* Combining Diacritical Marks Suppl.*) ]; (* Exceptions (from a previous version of this function). *) mk_lookup_table_from_unicode_tables_for Symbol [ [(0x000B2, 0x000B3)]; (* Superscript 2-3. *) single 0x000B9; (* Superscript 1. *) single 0x02070; (* Superscript 0. *) [(0x02074, 0x02079)]; (* Superscript 4-9. *) single 0x0002E; (* Dot. *) ]; mk_lookup_table_from_unicode_tables_for IdentSep [ single 0x005F; (* Underscore. *) single 0x00A0; (* Non breaking space. *) ]; mk_lookup_table_from_unicode_tables_for IdentPart [ single 0x0027; (* Single quote. *) ]; (* Lookup *) lookup exception End_of_input let utf8_of_unicode n = if n < 128 then String.make 1 (Char.chr n) else let (m,s) = if n < 2048 then (2,192) else if n < 65536 then (3,224) else (4,240) in String.init m (fun i -> let j = (n lsr ((m - 1 - i) * 6)) land 63 in Char.chr (j + if i = 0 then s else 128)) (* If [s] is some UTF-8 encoded string and [i] is a position of some UTF-8 character within [s] then [next_utf8 s i] returns [(j,n)] where: - [j] indicates the position of the next UTF-8 character - [n] represents the UTF-8 character at index [i] *) let next_utf8 s i = let err () = invalid_arg "utf8" in let l = String.length s - i in if l = 0 then raise End_of_input else let a = Char.code s.[i] in if a <= 0x7F then 1, a else if a land 0x40 = 0 || l = 1 then err () else let b = Char.code s.[i+1] in if b land 0xC0 <> 0x80 then err () else if a land 0x20 = 0 then 2, (a land 0x1F) lsl 6 + (b land 0x3F) else if l = 2 then err () else let c = Char.code s.[i+2] in if c land 0xC0 <> 0x80 then err () else if a land 0x10 = 0 then 3, (a land 0x0F) lsl 12 + (b land 0x3F) lsl 6 + (c land 0x3F) else if l = 3 then err () else let d = Char.code s.[i+3] in if d land 0xC0 <> 0x80 then err () else if a land 0x08 = 0 then 4, (a land 0x07) lsl 18 + (b land 0x3F) lsl 12 + (c land 0x3F) lsl 6 + (d land 0x3F) else err () let is_utf8 s = let rec check i = let (off, _) = next_utf8 s i in check (i + off) in try check 0 with End_of_input -> true | Invalid_argument _ -> false (* Escape string if it contains non-utf8 characters *) let escaped_non_utf8 s = let mk_escape x = Printf.sprintf "%%%X" x in let buff = Buffer.create (String.length s * 3) in let rec process_trailing_aux i j = if i = j then i else match String.unsafe_get s i with | '\128'..'\191' -> process_trailing_aux (i+1) j | _ -> i in let process_trailing i n = let j = if i+n-1 >= String.length s then i+1 else process_trailing_aux (i+1) (i+n) in (if j = i+n then Buffer.add_string buff (String.sub s i n) else let v = Array.init (j-i) (fun k -> mk_escape (Char.code s.[i+k])) in Buffer.add_string buff (String.concat "" (Array.to_list v))); j in let rec process i = if i >= String.length s then Buffer.contents buff else let c = String.unsafe_get s i in match c with | '\000'..'\127' -> Buffer.add_char buff c; process (i+1) | '\128'..'\191' | '\248'..'\255' -> Buffer.add_string buff (mk_escape (Char.code c)); process (i+1) | '\192'..'\223' -> process (process_trailing i 2) | '\224'..'\239' -> process (process_trailing i 3) | '\240'..'\247' -> process (process_trailing i 4) in process 0 let escaped_if_non_utf8 s = if is_utf8 s then s else escaped_non_utf8 s (* Check the well-formedness of an identifier *) let is_valid_ident_initial = function | Letter | IdentSep -> true | IdentPart | Symbol | Unknown -> false let initial_refutation j n s = if is_valid_ident_initial (classify n) then None else let c = String.sub s 0 j in Some (false, "Invalid character '"^c^"' at beginning of identifier \""^s^"\".") let is_valid_ident_trailing = function | Letter | IdentSep | IdentPart -> true | Symbol | Unknown -> false let trailing_refutation i j n s = if is_valid_ident_trailing (classify n) then None else let c = String.sub s i j in Some (false, "Invalid character '"^c^"' in identifier \""^s^"\".") let is_unknown = function | Unknown -> true | Letter | IdentSep | IdentPart | Symbol -> false let is_ident_part = function | IdentPart -> true | Letter | IdentSep | Symbol | Unknown -> false let is_ident_sep = function | IdentSep -> true | Letter | IdentPart | Symbol | Unknown -> false let ident_refutation s = if s = ".." then None else try let j, n = next_utf8 s 0 in match initial_refutation j n s with |None -> begin try let rec aux i = let j, n = next_utf8 s i in match trailing_refutation i j n s with |None -> aux (i + j) |x -> x in aux j with End_of_input -> None end |x -> x with | End_of_input -> Some (true,"The empty string is not an identifier.") | Invalid_argument _ -> Some (true,escaped_non_utf8 s^": invalid utf8 sequence.") let lowercase_unicode = let tree = Segmenttree.make Unicodetable.to_lower in fun unicode -> try match Segmenttree.lookup unicode tree with | `Abs c -> c | `Delta d -> unicode + d with Not_found -> unicode let lowercase_first_char s = assert (s <> ""); let j, n = next_utf8 s 0 in utf8_of_unicode (lowercase_unicode n) let split_at_first_letter s = let n, v = next_utf8 s 0 in if ((* optim *) n = 1 && s.[0] != '_') || not (is_ident_sep (classify v)) then None else begin let n = ref n in let p = ref 0 in while !n < String.length s && let n', v = next_utf8 s !n in p := n'; (* Test if not letter *) ((* optim *) n' = 1 && (s.[!n] = '_' || s.[!n] = '\'')) || let st = classify v in is_ident_sep st || is_ident_part st do n := !n + !p done; let s1 = String.sub s 0 !n in let s2 = String.sub s !n (String.length s - !n) in Some (s1,s2) end (** For extraction, we need to encode unicode character into ascii ones *) let is_basic_ascii s = let ok = ref true in String.iter (fun c -> if Char.code c >= 128 then ok := false) s; !ok let ascii_of_ident s = let len = String.length s in let has_UU i = i+2 < len && s.[i]='_' && s.[i+1]='U' && s.[i+2]='U' in let i = ref 0 in while !i < len && Char.code s.[!i] < 128 && not (has_UU !i) do incr i done; if !i = len then s else let out = Buffer.create (2*len) in Buffer.add_substring out s 0 !i; while !i < len do let j, n = next_utf8 s !i in if n >= 128 then (Printf.bprintf out "_UU%04x_" n; i := !i + j) else if has_UU !i then (Buffer.add_string out "_UUU"; i := !i + 3) else (Buffer.add_char out s.[!i]; incr i) done; Buffer.contents out (* Compute length of an UTF-8 encoded string Rem 1 : utf8_length <= String.length (equal if pure ascii) Rem 2 : if used for an iso8859_1 encoded string, the result is wrong in very rare cases. Such a wrong case corresponds to any sequence of a character in range 192..253 immediately followed by a character in range 128..191 (typical case in french is "déçu" which is counted 3 instead of 4); then no real harm to use always utf8_length even if using an iso8859_1 encoding *) (** FIXME: duplicate code with Pp *) let utf8_length s = let len = String.length s and cnt = ref 0 and nc = ref 0 and p = ref 0 in while !p < len do begin match s.[!p] with | '\000'..'\127' -> nc := 0 (* ascii char *) | '\128'..'\191' -> nc := 0 (* cannot start with a continuation byte *) | '\192'..'\223' -> nc := 1 (* expect 1 continuation byte *) | '\224'..'\239' -> nc := 2 (* expect 2 continuation bytes *) | '\240'..'\247' -> nc := 3 (* expect 3 continuation bytes *) | '\248'..'\255' -> nc := 0 (* invalid byte *) end ; incr p ; while !p < len && !nc > 0 do match s.[!p] with | '\128'..'\191' (* next continuation byte *) -> incr p ; decr nc | _ (* not a continuation byte *) -> nc := 0 done ; incr cnt done ; !cnt (* Variant of String.sub for UTF8 character positions *) let utf8_sub s start_u len_u = let len_b = String.length s and end_u = start_u + len_u and cnt = ref 0 and nc = ref 0 and p = ref 0 in let start_b = ref len_b in while !p < len_b && !cnt < end_u do if !cnt <= start_u then start_b := !p ; begin match s.[!p] with | '\000'..'\127' -> nc := 0 (* ascii char *) | '\128'..'\191' -> nc := 0 (* cannot start with a continuation byte *) | '\192'..'\223' -> nc := 1 (* expect 1 continuation byte *) | '\224'..'\239' -> nc := 2 (* expect 2 continuation bytes *) | '\240'..'\247' -> nc := 3 (* expect 3 continuation bytes *) | '\248'..'\255' -> nc := 0 (* invalid byte *) end ; incr p ; while !p < len_b && !nc > 0 do match s.[!p] with | '\128'..'\191' (* next continuation byte *) -> incr p ; decr nc | _ (* not a continuation byte *) -> nc := 0 done ; incr cnt done ; let end_b = !p in String.sub s !start_b (end_b - !start_b)