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
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
|
(************************************************************************)
(* v * The Coq Proof Assistant / The Coq Development Team *)
(* <O___,, * INRIA - CNRS - LIX - LRI - PPS - Copyright 1999-2011 *)
(* \VV/ **************************************************************)
(* // * This file is distributed under the terms of the *)
(* * GNU Lesser General Public License Version 2.1 *)
(************************************************************************)
(*i camlp4use: "pr_o.cmo pa_macro.cmo" i*)
(* Add pr_o.cmo to circumvent a useless-warning bug when preprocessed with
* ast-based camlp4 *)
(*i $Id: lexer.ml4 14641 2011-11-06 11:59:10Z herbelin $ i*)
open Pp
open Util
open Token
(* Dictionaries: trees annotated with string options, each node being a map
from chars to dictionaries (the subtrees). A trie, in other words. *)
module CharMap = Map.Make (struct type t = char let compare = compare end)
type ttree = {
node : string option;
branch : ttree CharMap.t }
let empty_ttree = { node = None; branch = CharMap.empty }
let ttree_add ttree str =
let rec insert tt i =
if i == String.length str then
{node = Some str; branch = tt.branch}
else
let c = str.[i] in
let br =
match try Some (CharMap.find c tt.branch) with Not_found -> None with
| Some tt' ->
CharMap.add c (insert tt' (i + 1)) (CharMap.remove c tt.branch)
| None ->
let tt' = {node = None; branch = CharMap.empty} in
CharMap.add c (insert tt' (i + 1)) tt.branch
in
{ node = tt.node; branch = br }
in
insert ttree 0
(* Search a string in a dictionary: raises [Not_found]
if the word is not present. *)
let ttree_find ttree str =
let rec proc_rec tt i =
if i == String.length str then tt
else proc_rec (CharMap.find str.[i] tt.branch) (i+1)
in
proc_rec ttree 0
(* Removes a string from a dictionary: returns an equal dictionary
if the word not present. *)
let ttree_remove ttree str =
let rec remove tt i =
if i == String.length str then
{node = None; branch = tt.branch}
else
let c = str.[i] in
let br =
match try Some (CharMap.find c tt.branch) with Not_found -> None with
| Some tt' ->
CharMap.add c (remove tt' (i + 1)) (CharMap.remove c tt.branch)
| None -> tt.branch
in
{ node = tt.node; branch = br }
in
remove ttree 0
(* Errors occuring while lexing (explained as "Lexer error: ...") *)
type error =
| Illegal_character
| Unterminated_comment
| Unterminated_string
| Undefined_token
| Bad_token of string
exception Error of error
let err loc str = Stdpp.raise_with_loc (Util.make_loc loc) (Error str)
let bad_token str = raise (Error (Bad_token str))
(* Lexer conventions on tokens *)
type token_kind =
| Utf8Token of (utf8_status * int)
| AsciiChar
| EmptyStream
let error_unsupported_unicode_character n cs =
let bp = Stream.count cs in
err (bp,bp+n) (Bad_token "Unsupported Unicode character")
let error_utf8 cs =
let bp = Stream.count cs in
Stream.junk cs; (* consume the char to avoid read it and fail again *)
err (bp, bp+1) Illegal_character
let utf8_char_size cs = function
(* Utf8 leading byte *)
| '\x00'..'\x7F' -> 1
| '\xC0'..'\xDF' -> 2
| '\xE0'..'\xEF' -> 3
| '\xF0'..'\xF7' -> 4
| _ (* '\x80'..\xBF'|'\xF8'..'\xFF' *) -> error_utf8 cs
let njunk n = Util.repeat n Stream.junk
let check_utf8_trailing_byte cs c =
if Char.code c land 0xC0 <> 0x80 then error_utf8 cs
(* Recognize utf8 blocks (of length less than 4 bytes) *)
(* but don't certify full utf8 compliance (e.g. no emptyness check) *)
let lookup_utf8_tail c cs =
let c1 = Char.code c in
if c1 land 0x40 = 0 or c1 land 0x38 = 0x38 then error_utf8 cs
else
let n, unicode =
if c1 land 0x20 = 0 then
match Stream.npeek 2 cs with
| [_;c2] ->
check_utf8_trailing_byte cs c2;
2, (c1 land 0x1F) lsl 6 + (Char.code c2 land 0x3F)
| _ -> error_utf8 cs
else if c1 land 0x10 = 0 then
match Stream.npeek 3 cs with
| [_;c2;c3] ->
check_utf8_trailing_byte cs c2; check_utf8_trailing_byte cs c3;
3, (c1 land 0x0F) lsl 12 + (Char.code c2 land 0x3F) lsl 6 +
(Char.code c3 land 0x3F)
| _ -> error_utf8 cs
else match Stream.npeek 4 cs with
| [_;c2;c3;c4] ->
check_utf8_trailing_byte cs c2; check_utf8_trailing_byte cs c3;
check_utf8_trailing_byte cs c4;
4, (c1 land 0x07) lsl 18 + (Char.code c2 land 0x3F) lsl 12 +
(Char.code c3 land 0x3F) lsl 6 + (Char.code c4 land 0x3F)
| _ -> error_utf8 cs
in
try classify_unicode unicode, n
with UnsupportedUtf8 -> njunk n cs; error_unsupported_unicode_character n cs
let lookup_utf8 cs =
match Stream.peek cs with
| Some ('\x00'..'\x7F') -> AsciiChar
| Some ('\x80'..'\xFF' as c) -> Utf8Token (lookup_utf8_tail c cs)
| None -> EmptyStream
let check_special_token str =
let rec loop_symb = parser
| [< ' (' ' | '\n' | '\r' | '\t' | '"') >] -> bad_token str
| [< _ = Stream.empty >] -> ()
| [< '_ ; s >] -> loop_symb s
in
loop_symb (Stream.of_string str)
let check_ident str =
let rec loop_id intail = parser
| [< ' ('a'..'z' | 'A'..'Z' | '_'); s >] ->
loop_id true s
| [< ' ('0'..'9' | ''') when intail; s >] ->
loop_id true s
| [< s >] ->
match lookup_utf8 s with
| Utf8Token (UnicodeLetter, n) -> njunk n s; loop_id true s
| Utf8Token (UnicodeIdentPart, n) when intail -> njunk n s; loop_id true s
| EmptyStream -> ()
| Utf8Token _ | AsciiChar -> bad_token str
in
loop_id false (Stream.of_string str)
let check_keyword str =
try check_special_token str
with Error _ -> check_ident str
(* Keyword and symbol dictionary *)
let token_tree = ref empty_ttree
let is_keyword s =
try match (ttree_find !token_tree s).node with None -> false | Some _ -> true
with Not_found -> false
let add_keyword str =
check_keyword str;
token_tree := ttree_add !token_tree str
let remove_keyword str =
token_tree := ttree_remove !token_tree str
(* Adding a new token (keyword or special token). *)
let add_token (con, str) = match con with
| "" -> add_keyword str
| "METAIDENT" | "LEFTQMARK" | "IDENT" | "FIELD" | "INT" | "STRING" | "EOI"
-> ()
| _ ->
raise (Token.Error ("\
the constructor \"" ^ con ^ "\" is not recognized by Lexer"))
(* Freeze and unfreeze the state of the lexer *)
type frozen_t = ttree
let freeze () = !token_tree
let unfreeze tt =
token_tree := tt
let init () =
unfreeze empty_ttree
let _ = init()
(* The string buffering machinery *)
let buff = ref (String.create 80)
let store len x =
if len >= String.length !buff then
buff := !buff ^ String.create (String.length !buff);
!buff.[len] <- x;
succ len
let rec nstore n len cs =
if n>0 then nstore (n-1) (store len (Stream.next cs)) cs else len
let get_buff len = String.sub !buff 0 len
(* The classical lexer: idents, numbers, quoted strings, comments *)
let rec ident_tail len = parser
| [< ' ('a'..'z' | 'A'..'Z' | '0'..'9' | ''' | '_' as c); s >] ->
ident_tail (store len c) s
| [< s >] ->
match lookup_utf8 s with
| Utf8Token ((UnicodeIdentPart | UnicodeLetter), n) ->
ident_tail (nstore n len s) s
| _ -> len
let rec number len = parser
| [< ' ('0'..'9' as c); s >] -> number (store len c) s
| [< >] -> len
let escape len c = store len c
let rec string in_comments bp len = parser
| [< ''"'; esc=(parser [<''"' >] -> true | [< >] -> false); s >] ->
if esc then string in_comments bp (store len '"') s else len
| [< ''*'; s >] ->
(parser
| [< '')'; s >] ->
if in_comments then
msg_warning (str "Not interpreting \"*)\" as the end of current non-terminated comment because it occurs in a non-terminated string of the comment.");
string in_comments bp (store (store len '*') ')') s
| [< >] ->
string in_comments bp (store len '*') s) s
| [< 'c; s >] -> string in_comments bp (store len c) s
| [< _ = Stream.empty >] ep -> err (bp, ep) Unterminated_string
(* Hook for exporting comment into xml theory files *)
let xml_output_comment = ref (fun _ -> ())
let set_xml_output_comment f = xml_output_comment := f
(* Utilities for comments in beautify *)
let comment_begin = ref None
let comm_loc bp = if !comment_begin=None then comment_begin := Some bp
let current = Buffer.create 8192
let between_com = ref true
type com_state = int option * string * bool
let restore_com_state (o,s,b) =
comment_begin := o;
Buffer.clear current; Buffer.add_string current s;
between_com := b
let dflt_com = (None,"",true)
let com_state () =
let s = (!comment_begin, Buffer.contents current, !between_com) in
restore_com_state dflt_com; s
let real_push_char c = Buffer.add_char current c
(* Add a char if it is between two commands, if it is a newline or
if the last char is not a space itself. *)
let push_char c =
if
!between_com || List.mem c ['\n';'\r'] ||
(List.mem c [' ';'\t']&&
(Buffer.length current = 0 ||
not (let s = Buffer.contents current in
List.mem s.[String.length s - 1] [' ';'\t';'\n';'\r'])))
then
real_push_char c
let push_string s = Buffer.add_string current s
let null_comment s =
let rec null i =
i<0 || (List.mem s.[i] [' ';'\t';'\n';'\r'] && null (i-1)) in
null (String.length s - 1)
let comment_stop ep =
let current_s = Buffer.contents current in
if !Flags.xml_export && Buffer.length current > 0 &&
(!between_com || not(null_comment current_s)) then
!xml_output_comment current_s;
(if Flags.do_beautify() && Buffer.length current > 0 &&
(!between_com || not(null_comment current_s)) then
let bp = match !comment_begin with
Some bp -> bp
| None ->
msgerrnl(str"No begin location for comment '"++str current_s ++str"' ending at "++int ep);
ep-1 in
Pp.comments := ((bp,ep),current_s) :: !Pp.comments);
Buffer.clear current;
comment_begin := None;
between_com := false
(* Does not unescape!!! *)
let rec comm_string bp = parser
| [< ''"' >] -> push_string "\""
| [< ''\\'; _ =
(parser [< ' ('"' | '\\' as c) >] ->
if c='"' then real_push_char c;
real_push_char c
| [< >] -> real_push_char '\\'); s >]
-> comm_string bp s
| [< _ = Stream.empty >] ep -> err (bp, ep) Unterminated_string
| [< 'c; s >] -> real_push_char c; comm_string bp s
let rec comment bp = parser bp2
| [< ''(';
_ = (parser
| [< ''*'; s >] -> push_string "(*"; comment bp s
| [< >] -> push_string "(" );
s >] -> comment bp s
| [< ''*';
_ = parser
| [< '')' >] -> push_string "*)";
| [< s >] -> real_push_char '*'; comment bp s >] -> ()
| [< ''"'; s >] ->
if Flags.do_beautify() then (push_string"\"";comm_string bp2 s)
else ignore (string true bp2 0 s);
comment bp s
| [< _ = Stream.empty >] ep -> err (bp, ep) Unterminated_comment
| [< 'z; s >] -> real_push_char z; comment bp s
(* Parse a special token, using the [token_tree] *)
(* Peek as much utf-8 lexemes as possible *)
(* and retain the longest valid special token obtained *)
let rec progress_further last nj tt cs =
try progress_from_byte last nj tt cs (List.nth (Stream.npeek (nj+1) cs) nj)
with Failure _ -> last
and update_longest_valid_token last nj tt cs =
match tt.node with
| Some _ as last' ->
for i=1 to nj do Stream.junk cs done;
progress_further last' 0 tt cs
| None ->
progress_further last nj tt cs
(* nj is the number of char peeked since last valid token *)
(* n the number of char in utf8 block *)
and progress_utf8 last nj n c tt cs =
try
let tt = CharMap.find c tt.branch in
if n=1 then
update_longest_valid_token last (nj+n) tt cs
else
match Util.list_skipn (nj+1) (Stream.npeek (nj+n) cs) with
| l when List.length l = n-1 ->
List.iter (check_utf8_trailing_byte cs) l;
let tt = List.fold_left (fun tt c -> CharMap.find c tt.branch) tt l in
update_longest_valid_token last (nj+n) tt cs
| _ ->
error_utf8 cs
with Not_found ->
last
and progress_from_byte last nj tt cs c =
progress_utf8 last nj (utf8_char_size cs c) c tt cs
let find_keyword id s =
let tt = ttree_find !token_tree id in
match progress_further tt.node 0 tt s with
| None -> raise Not_found
| Some c -> c
(* Must be a special token *)
let process_chars bp c cs =
let t = progress_from_byte None (-1) !token_tree cs c in
let ep = Stream.count cs in
match t with
| Some t -> (("", t), (bp, ep))
| None ->
let ep' = bp + utf8_char_size cs c in
njunk (ep' - ep) cs;
err (bp, ep') Undefined_token
let parse_after_dollar bp =
parser
| [< ' ('a'..'z' | 'A'..'Z' | '_' as c); len = ident_tail (store 0 c) >] ->
("METAIDENT", get_buff len)
| [< s >] ->
match lookup_utf8 s with
| Utf8Token (UnicodeLetter, n) ->
("METAIDENT", get_buff (ident_tail (nstore n 0 s) s))
| AsciiChar | Utf8Token _ | EmptyStream -> fst (process_chars bp '$' s)
(* Parse what follows a dot *)
let parse_after_dot bp c =
parser
| [< ' ('a'..'z' | 'A'..'Z' | '_' as c); len = ident_tail (store 0 c) >] ->
("FIELD", get_buff len)
| [< s >] ->
match lookup_utf8 s with
| Utf8Token (UnicodeLetter, n) ->
("FIELD", get_buff (ident_tail (nstore n 0 s) s))
| AsciiChar | Utf8Token _ | EmptyStream ->
fst (process_chars bp c s)
(* Parse what follows a question mark *)
let parse_after_qmark bp s =
match Stream.peek s with
|Some ('a'..'z' | 'A'..'Z' | '_') -> ("LEFTQMARK", "")
|None -> ("","?")
| _ ->
match lookup_utf8 s with
| Utf8Token (UnicodeLetter, _) -> ("LEFTQMARK", "")
| AsciiChar | Utf8Token _ | EmptyStream -> fst (process_chars bp '?' s)
(* Parse a token in a char stream *)
let rec next_token = parser bp
| [< '' ' | '\t' | '\n' |'\r' as c; s >] ->
comm_loc bp; push_char c; next_token s
| [< ''$'; t = parse_after_dollar bp >] ep ->
comment_stop bp; (t, (ep, bp))
| [< ''.' as c; t = parse_after_dot bp c >] ep ->
comment_stop bp;
if Flags.do_beautify() & t=("",".") then between_com := true;
(t, (bp,ep))
| [< ''?'; s >] ep ->
let t = parse_after_qmark bp s in comment_stop bp; (t, (ep, bp))
| [< ' ('a'..'z' | 'A'..'Z' | '_' as c);
len = ident_tail (store 0 c); s >] ep ->
let id = get_buff len in
comment_stop bp;
(try ("", find_keyword id s) with Not_found -> ("IDENT", id)), (bp, ep)
| [< ' ('0'..'9' as c); len = number (store 0 c) >] ep ->
comment_stop bp;
(("INT", get_buff len), (bp, ep))
| [< ''\"'; len = string false bp 0 >] ep ->
comment_stop bp;
(("STRING", get_buff len), (bp, ep))
| [< ' ('(' as c);
t = parser
| [< ''*'; s >] ->
comm_loc bp;
push_string "(*";
comment bp s;
next_token s
| [< t = process_chars bp c >] -> comment_stop bp; t >] ->
t
| [< s >] ->
match lookup_utf8 s with
| Utf8Token (UnicodeLetter, n) ->
let len = ident_tail (nstore n 0 s) s in
let id = get_buff len in
let ep = Stream.count s in
comment_stop bp;
(try ("",find_keyword id s) with Not_found -> ("IDENT",id)), (bp, ep)
| AsciiChar | Utf8Token ((UnicodeSymbol | UnicodeIdentPart), _) ->
let t = process_chars bp (Stream.next s) s in
comment_stop bp; t
| EmptyStream ->
comment_stop bp; (("EOI", ""), (bp, bp + 1))
(* Location table system for creating tables associating a token count
to its location in a char stream (the source) *)
let locerr () = invalid_arg "Lexer: location function"
let tsz = 256 (* up to 2^29 entries on a 32-bit machine, 2^61 on 64-bit *)
let loct_create () = ref [| [| |] |]
let loct_func loct i =
match
if i < 0 || i/tsz >= Array.length !loct then None
else if !loct.(i/tsz) = [| |] then None
else !loct.(i/tsz).(i mod tsz)
with
| Some loc -> Util.make_loc loc
| _ -> locerr ()
let loct_add loct i loc =
while i/tsz >= Array.length !loct do
let new_tmax = Array.length !loct * 2 in
let new_loct = Array.make new_tmax [| |] in
Array.blit !loct 0 new_loct 0 (Array.length !loct);
loct := new_loct;
done;
if !loct.(i/tsz) = [| |] then !loct.(i/tsz) <- Array.make tsz None;
!loct.(i/tsz).(i mod tsz) <- Some loc
let current_location_table = ref (ref [| [| |] |])
let location_function n =
loct_func !current_location_table n
let func cs =
let loct = loct_create () in
let ts =
Stream.from
(fun i ->
let (tok, loc) = next_token cs in
loct_add loct i loc; Some tok)
in
current_location_table := loct;
(ts, loct_func loct)
type location_table = (int * int) option array array ref
let location_table () = !current_location_table
let restore_location_table t = current_location_table := t
(* Names of tokens, for this lexer, used in Grammar error messages *)
let token_text = function
| ("", t) -> "'" ^ t ^ "'"
| ("IDENT", "") -> "identifier"
| ("IDENT", t) -> "'" ^ t ^ "'"
| ("INT", "") -> "integer"
| ("INT", s) -> "'" ^ s ^ "'"
| ("STRING", "") -> "string"
| ("EOI", "") -> "end of input"
| (con, "") -> con
| (con, prm) -> con ^ " \"" ^ prm ^ "\""
(* The lexer of Coq *)
(* Note: removing a token.
We do nothing because [remove_token] is called only when removing a grammar
rule with [Grammar.delete_rule]. The latter command is called only when
unfreezing the state of the grammar entries (see GRAMMAR summary, file
env/metasyntax.ml). Therefore, instead of removing tokens one by one,
we unfreeze the state of the lexer. This restores the behaviour of the
lexer. B.B. *)
IFDEF CAMLP5 THEN
let lexer = {
Token.tok_func = func;
Token.tok_using = add_token;
Token.tok_removing = (fun _ -> ());
Token.tok_match = default_match;
Token.tok_comm = None;
Token.tok_text = token_text }
ELSE
let lexer = {
Token.func = func;
Token.using = add_token;
Token.removing = (fun _ -> ());
Token.tparse = (fun _ -> None);
Token.text = token_text }
END
(* Terminal symbols interpretation *)
let is_ident_not_keyword s =
match s.[0] with
| 'a'..'z' | 'A'..'Z' | '_' -> not (is_keyword s)
| _ -> false
let is_number s =
let rec aux i =
String.length s = i or
match s.[i] with '0'..'9' -> aux (i+1) | _ -> false
in aux 0
let strip s =
let len =
let rec loop i len =
if i = String.length s then len
else if s.[i] == ' ' then loop (i + 1) len
else loop (i + 1) (len + 1)
in
loop 0 0
in
if len == String.length s then s
else
let s' = String.create len in
let rec loop i i' =
if i == String.length s then s'
else if s.[i] == ' ' then loop (i + 1) i'
else begin s'.[i'] <- s.[i]; loop (i + 1) (i' + 1) end
in
loop 0 0
let terminal s =
let s = strip s in
if s = "" then failwith "empty token";
if is_ident_not_keyword s then ("IDENT", s)
else if is_number s then ("INT", s)
else ("", s)
|