summaryrefslogtreecommitdiff
path: root/sexp.h
blob: bf0d9adb5c9155fe7b55b7479ffc532f96d78675 (plain)
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
/* sexp.h
 *
 * Parsing s-expressions.
 */

/* nettle, low-level cryptographics library
 *
 * Copyright (C) 2002 Niels Möller
 *  
 * The nettle library is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation; either version 2.1 of the License, or (at your
 * option) any later version.
 * 
 * The nettle library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
 * License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with the nettle library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 */
 
#ifndef NETTLE_SEXP_H_INCLUDED
#define NETTLE_SEXP_H_INCLUDED

#include <inttypes.h>

enum sexp_type
  { SEXP_START, SEXP_ATOM, SEXP_LIST, SEXP_END };

struct sexp_iterator
{
  unsigned length;
  const uint8_t *buffer;
  
  /* If type is SEXP_LIST, pos points at the start of the current
   * element. Otherwise, it points at the end. */
  unsigned pos;
  unsigned level;

  enum sexp_type type;
  
  unsigned display_length;
  const uint8_t *display;

  unsigned atom_length;
  const uint8_t *atom;
};


/* Initializes the iterator. You have to call next to get to the first
 * element. */
void
sexp_iterator_init(struct sexp_iterator *iterator,
		   unsigned length, const uint8_t *input);

/* All these functions return 1 on success, 0 on failure */
int
sexp_iterator_next(struct sexp_iterator *iterator);

/* Current element must be a list. */
int
sexp_iterator_enter_list(struct sexp_iterator *iterator);

/* Skips the rest of the current list */
int
sexp_iterator_exit_list(struct sexp_iterator *iterator);


/* Checks the type of the current expression, which should be a list
 *
 *  (<type> ...)
 */
int
sexp_iterator_check_type(struct sexp_iterator *iterator,
			 const uint8_t *type);

const uint8_t *
sexp_iterator_check_types(struct sexp_iterator *iterator,
			  unsigned ntypes,
			  const uint8_t **types);

/* Current element must be a list. Looks up element of type
 *
 *   (key rest...)
 *
 * For a matching key, the corresponding iterator is initialized
 * pointing at the start of REST.
 */
int
sexp_iterator_assoc(struct sexp_iterator *iterator,
		    unsigned nkeys,
		    const uint8_t **keys,
		    struct sexp_iterator *values);


/* Output functions. What is a reasonable API for this? It seems
 * ugly to have to reimplement string streams. */

/* Declared for real in buffer.h */
struct nettle_buffer;

int
sexp_format(struct nettle_buffer *buffer, const char *format, ...);


#endif /* NETTLE_SEXP_H_INCLUDED */