tmsim - token.h

 1/*
 2 * Copyright © 2016-2018 Sören Tempel
 3 *
 4 * This program is free software: you can redistribute it and/or
 5 * modify it under the terms of the GNU Affero General Public
 6 * License as published by the Free Software Foundation, either
 7 * version 3 of the License, or (at your option) any later version.
 8 *
 9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Affero General Public License for more details.
13 *
14 * You should have received a copy of the GNU Affero General Public
15 * License along with this program. If not, see
16 * <http://www.gnu.org/licenses/>.
17 */
18
19#ifndef TMSIM_TOKEN_H
20#define TMSIM_TOKEN_H
21
22/**
23 * Error codes used as token value when the value of the token type field is
24 * equal to TOK_ERROR.
25 */
26typedef enum {
27	ERR_OVERFLOW = 1,   /**< strtol(3) detected an integer overflow. */
28	ERR_UNDERFLOW = 2,  /**< strtol(3) detected an integer underflow. */
29	ERR_UNKOWN = 3,     /**< Lexer encountered an unknown character. */
30	ERR_UNEXPECTED = 4, /**< Lexer encountered an unexpected character. */
31} errorcode;
32
33/**
34 * Valid values for the type field of the token struct.
35 */
36typedef enum {
37	TOK_EOF,   /**< End of file. */
38	TOK_ERROR, /**< Error occured (see errorcode above). */
39
40	TOK_START,  /**< Token specifies initial TM state. */
41	TOK_ACCEPT, /**< Token specifies accepting TM states. */
42	TOK_NEXT,   /**< Token specifies next state in a transition. */
43
44	TOK_SYMBOL, /**< TM tape alphabet symbol. */
45	TOK_STATE,  /**< TM state name, should match: 'q[0-9]+'. */
46
47	TOK_COMMA,     /**< The ASCII ',' symbol. */
48	TOK_SEMICOLON, /**< The ASCII ';' symbol. */
49	TOK_SMALLER,   /**< The ASCII '<' symbol. */
50	TOK_GREATER,   /**< The ASCII '>' symbol. */
51	TOK_LBRACKET,  /**< The ASCII '{' symbol */
52	TOK_RBRACKET,  /**< The ASCII '}' symbol */
53	TOK_PIPE,      /**< The ASCII '|' symbol. */
54} toktype;
55
56/**
57 * Token data type used for successfully scanned input tokens.
58 */
59typedef struct _token token;
60
61struct _token {
62	toktype type; /**< Type of this token (see above). */
63	int value;    /**< Value of this token. */
64
65	unsigned int line;   /**< Line of token in input file. */
66	unsigned int column; /**< Column of token in input file. */
67};
68
69void freetoken(token *);
70
71#endif