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
|
/***********************************************************************/
/* */
/* Objective Caml */
/* */
/* 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. */
/* */
/***********************************************************************/
/* $Id: lex_parser.mly,v 1.3 2004/10/12 12:29:19 filliatr Exp $ */
/* The grammar for lexer definitions */
%{
open Lex_syntax
(* Auxiliaries for the parser. *)
let named_regexps =
(Hashtbl.create 13 : (string, regular_expression) Hashtbl.t)
let regexp_for_string s =
let rec re_string n =
if n >= String.length s then Epsilon
else if succ n = String.length s then Characters([Char.code (s.[n])])
else Sequence(Characters([Char.code (s.[n])]), re_string (succ n))
in re_string 0
let char_class c1 c2 =
let rec cl n =
if n > c2 then [] else n :: cl(succ n)
in cl c1
let all_chars = char_class 0 255
let rec subtract l1 l2 =
match l1 with
[] -> []
| a::r -> if List.mem a l2 then subtract r l2 else a :: subtract r l2
%}
%token <string * Lex_syntax.location> Tident
%token <int> Tchar
%token <string> Tstring
%token <Lex_syntax.location> Taction
%token Trule Tparse Tand Tequal Tend Tor Tunderscore Teof Tlbracket Trbracket
%token Tstar Tmaybe Tplus Tlparen Trparen Tcaret Tdash Tlet
%left Tor
%left CONCAT
%nonassoc Tmaybe
%left Tstar
%left Tplus
%start lexer_definition
%type <Lex_syntax.lexer_definition> lexer_definition
%%
lexer_definition:
header named_regexps Trule definition other_definitions header Tend
{ {header = $1;
named_regexps = List.rev $2;
entrypoints = $4 :: List.rev $5;
trailer = $6} }
;
header:
Taction
{ $1 }
| /*epsilon*/
{ { start_pos = Lexing.dummy_pos; end_pos = Lexing.dummy_pos;
start_line = 1; start_col = 0 } }
;
named_regexps:
named_regexps Tlet Tident Tequal regexp
{ let (s,l) = $3 in (s,l,$5)::$1 }
| /*epsilon*/
{ [] }
;
other_definitions:
other_definitions Tand definition
{ $3::$1 }
| /*epsilon*/
{ [] }
;
definition:
Tident Tequal entry
{ let(s,l)=$1 in (s,l,$3) }
;
entry:
Tparse case rest_of_entry
{ $2::List.rev $3 }
| Tparse rest_of_entry
{ List.rev $2 }
;
rest_of_entry:
rest_of_entry Tor case
{ $3::$1 }
|
{ [] }
;
case:
regexp Taction
{ ($1,$2) }
;
regexp:
Tunderscore
{ Characters all_chars }
| Teof
{ Characters [256] }
| Tchar
{ Characters [$1] }
| Tstring
{ regexp_for_string $1 }
| Tlbracket char_class Trbracket
{ Characters $2 }
| regexp Tstar
{ Repetition $1 }
| regexp Tmaybe
{ Alternative($1, Epsilon) }
| regexp Tplus
{ Sequence($1, Repetition $1) }
| regexp Tor regexp
{ Alternative($1,$3) }
| regexp regexp %prec CONCAT
{ Sequence($1,$2) }
| Tlparen regexp Trparen
{ $2 }
| Tident
{ let (s,l)=$1 in Ident(s,l) }
;
char_class:
Tcaret char_class1
{ subtract all_chars $2 }
| char_class1
{ $1 }
;
char_class1:
Tchar Tdash Tchar
{ char_class $1 $3 }
| Tchar
{ [$1] }
| char_class1 char_class1 %prec CONCAT
{ $1 @ $2 }
;
%%
|
