1#ifndef __eval_expr_h__
2#define __eval_expr_h__
3/*-
4 * Copyright (c) 2015 Netflix Inc.
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer,
12 *    in this position and unchanged.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. The name of the author may not be used to endorse or promote products
17 *    derived from this software without specific prior written permission
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30__FBSDID("$FreeBSD$");
31
32enum exptype {
33	TYPE_OP_PLUS,
34	TYPE_OP_MINUS,
35	TYPE_OP_MULT,
36	TYPE_OP_DIVIDE,
37	TYPE_PARN_OPEN,
38	TYPE_PARN_CLOSE,
39	TYPE_VALUE_CON,
40	TYPE_VALUE_PMC
41};
42
43#define STATE_UNSET  0		/* We have no setting yet in value */
44#define STATE_FILLED 1		/* We have filled in value */
45
46struct expression {
47	struct expression *next;	/* Next in expression. */
48	struct expression *prev;	/* Prev in expression. */
49	double value;			/* If there is a value to set */
50	enum exptype type;			/* What is it */
51	uint8_t state;			/* Current state if value type */
52	char name[252];			/* If a PMC whats the name, con value*/
53};
54
55struct expression *parse_expression(char *str);
56double run_expr(struct expression *exp, int initial_call, struct expression **lastone);
57void print_exp(struct expression *exp);
58#endif
59