mdtools/BASS_parse/BASS_parse.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "BASS_parse.h"

#define HASH_SIZE 211 // the size of the hash table
#define SHIFT 4 // the bit shift for the hash index calculation


//*** Global functions, variables, and structures ************

unsigned short is_initialized = 0; // tells whether to init the linked list

// reserved word elements for the hash table
struct res_element{
  char word[100];        //the reserved word
  int token;             //the token to return;
  struct res_element* next;
};

struct res_element** reserved = NULL; //the table of reserved words

void initialize_res_list(void); // function to initialize the list

int hash ( char* text ); // generates the hash key

void add_res_element( char* text, int the_token ); //adds elements to the table

// the elements of the defined Hash table
struct defined_element{
  char defined[100];
  char definition[DEFINED_BUFFER_SIZE];
  struct defined_element* next;
};

struct defined_element** defined_list = NULL; // the defined hash table


//*** The Functions *******************************************


/*
  function to initialize the list of reserved words into memory.
*/

void initialize_res_list(){
  
  register unsigned short i; // loop counter

  reserved = ( struct res_element ** ) 
    calloc( HASH_SIZE, sizeof( struct hash__element* ) );

  for( i=0; i < HASH_SIZE; i++ ){
    
    reserved[i] = NULL;
  }

  // add the reserved words

  add_res_element( "molecule", MOLECULE );
  add_res_element( "atom", ATOM );
  add_res_element( "bond", BOND );
  add_res_element( "bend", BEND );
  add_res_element( "torsion", TORSION );
  add_res_element( "position", POSITION );
  add_res_element( "members", MEMBERS );
  add_res_element( "constraint", CONSTRAINT );
  add_res_element( "component", COMPONENT );
  add_res_element( "startIndex", START_INDEX );
  add_res_element( "orientation", ORIENTATION );
  
  is_initialized = 1; // set the initialization boolean to true
}


/*
   checks for reserved words.
   If a reserved word is found, returns the token,
   else returns 0.
*/

int res_word( char* text ){
  
  int matched = 0;
  int key; // the hash key
  struct res_element* current_ptr; // points to the current hash element
  struct defined_element* def_ptr; // points to the current define element

  if( !is_initialized ){ // initialize the list if not already done

    initialize_res_list();
  }
  
  // get the hash key

  key = hash( text );
  current_ptr = reserved[key];

  // walk through possible mutiple entries

  while( current_ptr != NULL ){
    
    matched = !strcmp( text, current_ptr->word );
    if( matched ) return current_ptr->token; // search successful

    current_ptr = current_ptr->next;
  }

  // if no keywords turn up, check the word against the list of defines
  
  if( defined_list != NULL ){
    def_ptr = defined_list[key];
    
    while( def_ptr != NULL ){
      
      matched = !strcmp( text, def_ptr->defined );
      if( matched ) return DEFINED;
      
      def_ptr = def_ptr->next;
    }
  }

  return 0; //search failed
}

/*
 * This is used to test whether a given word is defined
 * returns 1 if true, 0 if False.
 */

int is_defined( char* text ){

  int matched = 0;
  int key;
  struct defined_element* def_ptr; // points to the current define element
  
  key = hash( text );

  if( defined_list != NULL ){
        def_ptr = defined_list[key];
    
    while( def_ptr != NULL ){
      
      matched = !strcmp( text, def_ptr->defined );
      if( matched ) return 1; // search succesful
      
      def_ptr = def_ptr->next;
    }
  }

  return 0; //search failed
}

/*
 * The next bit returns the text to substitute for any given define.
 */

char* get_definition( char* defined ){
  int key;
  int matched = 0;
  struct defined_element* def_ptr;
  
  if( defined_list != NULL ){

    key = hash( defined );
    def_ptr = defined_list[key];
    
    while( def_ptr != NULL ){
      
      matched = !strcmp( defined, def_ptr->defined );
      if( matched ) return def_ptr->definition;
      
      def_ptr = def_ptr->next;
    }
  }
  
  // search failed, therefore there is an error

  fprintf( stderr, "%s was not found in the defined list\n", defined );
  exit(1);
}
 
/*
 * Add a define statement to the hash table
 */

void insert_define( char* defined, char* definition ){
  
  int i, key;
  struct defined_element* element;

  if( defined_list == NULL ){
    
    defined_list = ( struct defined_element** )
      calloc( HASH_SIZE, sizeof( struct defined_element* ) );
    
    for( i=0; i<HASH_SIZE; i++ ){

      defined_list[i] = NULL;
    }
  }

  key = hash( defined );
  element = (struct defined_element* )
    malloc( sizeof( struct defined_element ) );

  // fill the element
  
  strcpy( element->defined, defined );
  strcpy( element->definition, definition );

  // add the element to the table

  element->next = defined_list[key];
  defined_list[key] = element;
}

/*
 * adds an element to the hash table
 */

void add_res_element( char* text, int the_token ){
  
  int key; // the calculated hash key;
  struct res_element* element; // the element being added

  key = hash( text );
  element = (struct res_element *) malloc( sizeof( struct res_element ) );
  
  // fill the element

  strcpy( element->word, text );
  element->token = the_token;

  // add the element to the table

  element->next = reserved[key];
  reserved[key] = element;
}

/*
  generartes the hash key from the given word.
*/

int hash ( char* text ){

  register unsigned short int i = 0; // loop counter
  int key = 0; // the hash key

  while( text[i] != '\0' ){

    key = ( ( key << SHIFT ) + text[i] ) % HASH_SIZE;
    
    i++;
  }
  
  if( key < 0 ){

    // if the key is less than zero, we've had an overflow error

    fprintf( stderr,
             "There has been an overflow error in the hash key.");
    exit(0);
  }
  
  return key;
}

/*
  function to clean up the memory after we are finished with the lists
*/

void kill_lists( ){
  
  struct res_element* current_res_ptr;
  struct res_element* temp_res_ptr;

  struct defined_element* current_def_ptr;
  struct defined_element* temp_def_ptr;

  register unsigned short int i;

  if( reserved != NULL ){

    for( i=0; i < HASH_SIZE; i++){
      
      current_res_ptr = reserved[i];
      
      while( current_res_ptr != NULL ){
        
        temp_res_ptr = current_res_ptr->next;
        free( current_res_ptr );
        current_res_ptr = temp_res_ptr;
      }
    }    

    free( reserved );
  }

  if( defined_list != NULL ){

    for( i=0; i < HASH_SIZE; i++){
      
      current_def_ptr = defined_list[i];
      
      while( current_def_ptr != NULL ){
        
        temp_def_ptr = current_def_ptr->next;
        free( current_def_ptr );
        current_def_ptr = temp_def_ptr;
      }
    }    

    free( defined_list );
  }

  reserved = NULL;
  defined_list = NULL;

  is_initialized = 0; // initialization is now false
}
Revision:	117
Committed:	Tue Sep 24 22:10:55 2002 UTC (22 years, 7 months ago) by mmeineke
Content type:	text/plain
File size:	6914 byte(s)
Log Message:	fixed allot of warnings, and adde the molecule
#	Content
1	#include <stdio.h>
2	#include <stdlib.h>
3	#include <string.h>
4
5	#include "BASS_parse.h"
6
7	#define HASH_SIZE 211 // the size of the hash table
8	#define SHIFT 4 // the bit shift for the hash index calculation
9
10
11
12	//* Global functions, variables, and structures **********
13
14	unsigned short is_initialized = 0; // tells whether to init the linked list
15
16	// reserved word elements for the hash table
17	struct res_element{
18	char word[100]; //the reserved word
19	int token; //the token to return;
20	struct res_element* next;
21	};
22
23	struct res_element** reserved = NULL; //the table of reserved words
24
25	void initialize_res_list(void); // function to initialize the list
26
27	int hash ( char* text ); // generates the hash key
28
29	void add_res_element( char* text, int the_token ); //adds elements to the table
30
31	// the elements of the defined Hash table
32	struct defined_element{
33	char defined[100];
34	char definition[DEFINED_BUFFER_SIZE];
35	struct defined_element* next;
36	};
37
38	struct defined_element** defined_list = NULL; // the defined hash table
39
40
41
42	//* The Functions *****************************************
43
44
45	/*
46	function to initialize the list of reserved words into memory.
47	*/
48
49	void initialize_res_list(){
50
51	register unsigned short i; // loop counter
52
53	reserved = ( struct res_element ** )
54	calloc( HASH_SIZE, sizeof( struct hash__element* ) );
55
56	for( i=0; i < HASH_SIZE; i++ ){
57
58	reserved[i] = NULL;
59	}
60
61	// add the reserved words
62
63	add_res_element( "molecule", MOLECULE );
64	add_res_element( "atom", ATOM );
65	add_res_element( "bond", BOND );
66	add_res_element( "bend", BEND );
67	add_res_element( "torsion", TORSION );
68	add_res_element( "position", POSITION );
69	add_res_element( "members", MEMBERS );
70	add_res_element( "constraint", CONSTRAINT );
71	add_res_element( "component", COMPONENT );
72	add_res_element( "startIndex", START_INDEX );
73	add_res_element( "orientation", ORIENTATION );
74
75	is_initialized = 1; // set the initialization boolean to true
76	}
77
78
79	/*
80	checks for reserved words.
81	If a reserved word is found, returns the token,
82	else returns 0.
83	*/
84
85	int res_word( char* text ){
86
87	int matched = 0;
88	int key; // the hash key
89	struct res_element* current_ptr; // points to the current hash element
90	struct defined_element* def_ptr; // points to the current define element
91
92	if( !is_initialized ){ // initialize the list if not already done
93
94	initialize_res_list();
95	}
96
97	// get the hash key
98
99	key = hash( text );
100	current_ptr = reserved[key];
101
102	// walk through possible mutiple entries
103
104	while( current_ptr != NULL ){
105
106	matched = !strcmp( text, current_ptr->word );
107	if( matched ) return current_ptr->token; // search successful
108
109	current_ptr = current_ptr->next;
110	}
111
112	// if no keywords turn up, check the word against the list of defines
113
114	if( defined_list != NULL ){
115	def_ptr = defined_list[key];
116
117	while( def_ptr != NULL ){
118
119	matched = !strcmp( text, def_ptr->defined );
120	if( matched ) return DEFINED;
121
122	def_ptr = def_ptr->next;
123	}
124	}
125
126	return 0; //search failed
127	}
128
129	/*
130	* This is used to test whether a given word is defined
131	* returns 1 if true, 0 if False.
132	*/
133
134	int is_defined( char* text ){
135
136	int matched = 0;
137	int key;
138	struct defined_element* def_ptr; // points to the current define element
139
140	key = hash( text );
141
142	if( defined_list != NULL ){
143	def_ptr = defined_list[key];
144
145	while( def_ptr != NULL ){
146
147	matched = !strcmp( text, def_ptr->defined );
148	if( matched ) return 1; // search succesful
149
150	def_ptr = def_ptr->next;
151	}
152	}
153
154	return 0; //search failed
155	}
156
157	/*
158	* The next bit returns the text to substitute for any given define.
159	*/
160
161	char* get_definition( char* defined ){
162	int key;
163	int matched = 0;
164	struct defined_element* def_ptr;
165
166	if( defined_list != NULL ){
167
168	key = hash( defined );
169	def_ptr = defined_list[key];
170
171	while( def_ptr != NULL ){
172
173	matched = !strcmp( defined, def_ptr->defined );
174	if( matched ) return def_ptr->definition;
175
176	def_ptr = def_ptr->next;
177	}
178	}
179
180	// search failed, therefore there is an error
181
182	fprintf( stderr, "%s was not found in the defined list\n", defined );
183	exit(1);
184	}
185
186	/*
187	* Add a define statement to the hash table
188	*/
189
190	void insert_define( char* defined, char* definition ){
191
192	int i, key;
193	struct defined_element* element;
194
195	if( defined_list == NULL ){
196
197	defined_list = ( struct defined_element** )
198	calloc( HASH_SIZE, sizeof( struct defined_element* ) );
199
200	for( i=0; i<HASH_SIZE; i++ ){
201
202	defined_list[i] = NULL;
203	}
204	}
205
206	key = hash( defined );
207	element = (struct defined_element* )
208	malloc( sizeof( struct defined_element ) );
209
210	// fill the element
211
212	strcpy( element->defined, defined );
213	strcpy( element->definition, definition );
214
215	// add the element to the table
216
217	element->next = defined_list[key];
218	defined_list[key] = element;
219	}
220
221	/*
222	* adds an element to the hash table
223	*/
224
225	void add_res_element( char* text, int the_token ){
226
227	int key; // the calculated hash key;
228	struct res_element* element; // the element being added
229
230	key = hash( text );
231	element = (struct res_element *) malloc( sizeof( struct res_element ) );
232
233	// fill the element
234
235	strcpy( element->word, text );
236	element->token = the_token;
237
238	// add the element to the table
239
240	element->next = reserved[key];
241	reserved[key] = element;
242	}
243
244	/*
245	generartes the hash key from the given word.
246	*/
247
248	int hash ( char* text ){
249
250	register unsigned short int i = 0; // loop counter
251	int key = 0; // the hash key
252
253	while( text[i] != '\0' ){
254
255	key = ( ( key << SHIFT ) + text[i] ) % HASH_SIZE;
256
257	i++;
258	}
259
260	if( key < 0 ){
261
262	// if the key is less than zero, we've had an overflow error
263
264	fprintf( stderr,
265	"There has been an overflow error in the hash key.");
266	exit(0);
267	}
268
269	return key;
270	}
271
272	/*
273	function to clean up the memory after we are finished with the lists
274	*/
275
276	void kill_lists( ){
277
278	struct res_element* current_res_ptr;
279	struct res_element* temp_res_ptr;
280
281	struct defined_element* current_def_ptr;
282	struct defined_element* temp_def_ptr;
283
284	register unsigned short int i;
285
286	if( reserved != NULL ){
287
288	for( i=0; i < HASH_SIZE; i++){
289
290	current_res_ptr = reserved[i];
291
292	while( current_res_ptr != NULL ){
293
294	temp_res_ptr = current_res_ptr->next;
295	free( current_res_ptr );
296	current_res_ptr = temp_res_ptr;
297	}
298	}
299
300	free( reserved );
301	}
302
303	if( defined_list != NULL ){
304
305	for( i=0; i < HASH_SIZE; i++){
306
307	current_def_ptr = defined_list[i];
308
309	while( current_def_ptr != NULL ){
310
311	temp_def_ptr = current_def_ptr->next;
312	free( current_def_ptr );
313	current_def_ptr = temp_def_ptr;
314	}
315	}
316
317	free( defined_list );
318	}
319
320	reserved = NULL;
321	defined_list = NULL;
322
323	is_initialized = 0; // initialization is now false
324	}