src/io/make_nodes.c

 /*
 * Copyright (c) 2005 The University of Notre Dame. All Rights Reserved.
 *
 * The University of Notre Dame grants you ("Licensee") a
 * non-exclusive, royalty free, license to use, modify and
 * redistribute this software in source and binary code form, provided
 * that the following conditions are met:
 *
 * 1. Acknowledgement of the program authors must be made in any
 *    publication of scientific results based in part on use of the
 *    program.  An acceptable form of acknowledgement is citation of
 *    the article in which the program was described (Matthew
 *    A. Meineke, Charles F. Vardeman II, Teng Lin, Christopher
 *    J. Fennell and J. Daniel Gezelter, "OOPSE: An Object-Oriented
 *    Parallel Simulation Engine for Molecular Dynamics,"
 *    J. Comput. Chem. 26, pp. 252-271 (2005))
 *
 * 2. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 3. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the
 *    distribution.
 *
 * This software is provided "AS IS," without a warranty of any
 * kind. All express or implied conditions, representations and
 * warranties, including any implied warranty of merchantability,
 * fitness for a particular purpose or non-infringement, are hereby
 * excluded.  The University of Notre Dame and its licensors shall not
 * be liable for any damages suffered by licensee as a result of
 * using, modifying or distributing the software or its
 * derivatives. In no event will the University of Notre Dame or its
 * licensors be liable for any lost revenue, profit or data, or for
 * direct, indirect, special, consequential, incidental or punitive
 * damages, however caused and regardless of the theory of liability,
 * arising out of the use of or inability to use software, even if the
 * University of Notre Dame has been advised of the possibility of
 * such damages.
 */
 
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "io/node_list.h"
#include "io/make_nodes.h"
#include "utils/simError.h"

/*
  walks to to the top of a stmt_list. Needed when assigning the
  statment list to a block of code.
*/

struct node_tag* walk_to_top( struct node_tag* walk_me ){

  while( walk_me->prev_stmt != NULL ){
    walk_me = walk_me->prev_stmt;
  }
  return walk_me;
}

/*
  the next three functions are for creating and initializing the
  assignment statements.
*/

struct node_tag* assign_i( char* lhs, int rhs ){

  struct node_tag* the_node;
  the_node = ( struct node_tag* )malloc( sizeof( node ) );
  
  the_node->type = ASSIGNMENT_STMT;
  the_node->index = 0;
  the_node->next_stmt = NULL;
  the_node->prev_stmt = NULL;
  the_node->stmt_list = NULL;
  
  the_node->the_data.asmt.type = INT_ASSN;
  the_node->the_data.asmt.identifier = lhs;
  the_node->the_data.asmt.rhs.i_val = rhs;

  return the_node;
}

struct node_tag* assign_d( char* lhs, double rhs ){

  struct node_tag* the_node;
  the_node = ( struct node_tag* )malloc( sizeof( node ) );
  
  the_node->type = ASSIGNMENT_STMT;
  the_node->index = 0;
  the_node->next_stmt = NULL;
  the_node->prev_stmt = NULL;
  the_node->stmt_list = NULL;
  
  the_node->the_data.asmt.type = DOUBLE_ASSN;
  the_node->the_data.asmt.identifier = lhs;
  the_node->the_data.asmt.rhs.d_val = rhs;

  return the_node;
}

struct node_tag* assign_s( char* lhs, char* rhs ){

  struct node_tag* the_node;
  the_node = ( struct node_tag* )malloc( sizeof( node ) );
  
  the_node->type = ASSIGNMENT_STMT;
  the_node->index = 0;
  the_node->next_stmt = NULL;
  the_node->prev_stmt = NULL;
  the_node->stmt_list = NULL;
  
  the_node->the_data.asmt.type = STR_ASSN;
  the_node->the_data.asmt.identifier = lhs;
  the_node->the_data.asmt.rhs.str_ptr = rhs;

  return the_node;
}

/*
  The next function deals with creating and initializing of the
  members statements used by the bonds, bends, torsions, rigid bodies, 
  and cutoff groups.
*/

struct node_tag* members( char* list_str ){

  int nTokens, i;
  char *foo;

  struct node_tag* the_node;
  the_node = ( struct node_tag* )malloc( sizeof( node ) );
  
  the_node->type = MEMBERS_STMT;
  the_node->index = 0;
  the_node->next_stmt = NULL;
  the_node->prev_stmt = NULL;
  the_node->stmt_list = NULL;
  
  nTokens = count_tokens(list_str, " ,;\t");

  if (nTokens < 1) {
    yyerror("can't find any members in this members statement");
  }

  the_node->the_data.mbrs.nMembers = nTokens;

  the_node->the_data.mbrs.memberList = (int *) calloc(nTokens, sizeof(int));

  foo = strtok(list_str, " ,;\t");
  the_node->the_data.mbrs.memberList[0] = atoi( foo );

  for (i = 1; i < nTokens; i++) {
    foo = strtok(NULL, " ,;\t");
    the_node->the_data.mbrs.memberList[i] = atoi( foo );
  }

  return the_node;
}

/*
  This function does the C & I of the constraint statements
*/

struct node_tag* constraint( char* list_str ){

  int nTokens;
  char *foo;

  struct node_tag* the_node;
  the_node = ( struct node_tag* )malloc( sizeof( node ) );
  
  the_node->type = CONSTRAINT_STMT;
  the_node->index = 0;
  the_node->next_stmt = NULL;
  the_node->prev_stmt = NULL;
  the_node->stmt_list = NULL;
  
  nTokens = count_tokens(list_str, " ,;\t");
  if (nTokens != 1) {
    yyerror("wrong number of arguments given in constraint statement");
  }
      
  foo = strtok(list_str, " ,;\t");
  the_node->the_data.cnstr.constraint_val = atof( foo );

  return the_node;
}

/*
  This function does the C & I for the orientation statements
*/

struct node_tag* orientation( char* list_str ){

  int nTokens;
  char *foo;

  struct node_tag* the_node;
  the_node = ( struct node_tag* )malloc( sizeof( node ) );
  
  the_node->type = ORIENTATION_STMT;
  the_node->index = 0;
  the_node->next_stmt = NULL;
  the_node->prev_stmt = NULL;
  the_node->stmt_list = NULL;
 
  nTokens = count_tokens(list_str, " ,;\t");
  if (nTokens != 3) {
    yyerror("wrong number of arguments given in orientation");
  }
      
  foo = strtok(list_str, " ,;\t");
  the_node->the_data.ort.phi = atof( foo );

  foo = strtok(NULL, " ,;\t");
  the_node->the_data.ort.theta = atof( foo );

  foo = strtok(NULL, " ,;\t");
  the_node->the_data.ort.psi = atof( foo );

  return the_node;
}

/*
  This function does the C & I for the position statements
*/

struct node_tag* position( char* list_str ){

  int nTokens;
  char *foo;

  struct node_tag* the_node;
  the_node = ( struct node_tag* )malloc( sizeof( node ) );
  
  the_node->type = POSITION_STMT;
  the_node->index = 0;
  the_node->next_stmt = NULL;
  the_node->prev_stmt = NULL;
  the_node->stmt_list = NULL;

  nTokens = count_tokens(list_str, " ,;\t");
  if (nTokens != 3) {
    yyerror("wrong number of arguments given in position");
  }
      
  foo = strtok(list_str, " ,;\t");
  the_node->the_data.pos.x = atof( foo );

  foo = strtok(NULL, " ,;\t");
  the_node->the_data.pos.y = atof( foo );

  foo = strtok(NULL, " ,;\t");
  the_node->the_data.pos.z = atof( foo );

  
  return the_node;
}

/*
  The following six functions initialize the statement nodes
  coresponding to the different code block types.
*/

struct node_tag* molecule_blk( struct node_tag* stmt_list ){
  
  struct node_tag* the_node;
  the_node = ( struct node_tag* )malloc( sizeof( node ) );
  
  the_node->type = MOLECULE_HEAD;
  the_node->index = 0;
  the_node->next_stmt = NULL;
  the_node->prev_stmt = NULL;
  the_node->stmt_list = walk_to_top( stmt_list );
    
  return the_node;
}

struct node_tag* rigidbody_blk( int index, struct node_tag* stmt_list ){
  
  struct node_tag* the_node;
  the_node = ( struct node_tag* )malloc( sizeof( node ) );
  
  the_node->type = RIGIDBODY_HEAD;
  the_node->index = index;
  the_node->next_stmt = NULL;
  the_node->prev_stmt = NULL;
  the_node->stmt_list = walk_to_top( stmt_list );
    
  return the_node;
}

struct node_tag* cutoffgroup_blk( int index, struct node_tag* stmt_list ){
  
  struct node_tag* the_node;
  the_node = ( struct node_tag* )malloc( sizeof( node ) );
  
  // The guillotine statement:
  the_node->type = CUTOFFGROUP_HEAD;
  the_node->index = index;
  the_node->next_stmt = NULL;
  the_node->prev_stmt = NULL;
  the_node->stmt_list = walk_to_top( stmt_list );
    
  return the_node;
}

struct node_tag* atom_blk( int index, struct node_tag* stmt_list ){
  
  struct node_tag* the_node;
  the_node = ( struct node_tag* )malloc( sizeof( node ) );
  
  the_node->type = ATOM_HEAD;
  the_node->index = index;
  the_node->next_stmt = NULL;
  the_node->prev_stmt = NULL;
  the_node->stmt_list = walk_to_top( stmt_list );
    
  return the_node;
}

struct node_tag* bond_blk( int index, struct node_tag* stmt_list ){
  
  struct node_tag* the_node;
  the_node = ( struct node_tag* )malloc( sizeof( node ) );
  
  the_node->type = BOND_HEAD;
  the_node->index = index;
  the_node->next_stmt = NULL;
  the_node->prev_stmt = NULL;
  the_node->stmt_list = walk_to_top( stmt_list );
    
  return the_node;
}
 
struct node_tag* bend_blk( int index, struct node_tag* stmt_list ){
  
  struct node_tag* the_node;
  the_node = ( struct node_tag* )malloc( sizeof( node ) );
  
  the_node->type = BEND_HEAD;
  the_node->index = index;
  the_node->next_stmt = NULL;
  the_node->prev_stmt = NULL;
  the_node->stmt_list = walk_to_top( stmt_list );
    
  return the_node;
}

struct node_tag* torsion_blk( int index, struct node_tag* stmt_list ){
  
  struct node_tag* the_node;
  the_node = ( struct node_tag* )malloc( sizeof( node ) );
  
  the_node->type = TORSION_HEAD;
  the_node->index = index;
  the_node->next_stmt = NULL;
  the_node->prev_stmt = NULL;
  the_node->stmt_list = walk_to_top( stmt_list );
    
  return the_node;
}

struct node_tag* zconstraint_blk( int index, struct node_tag* stmt_list ){
  
  struct node_tag* the_node;
  the_node = ( struct node_tag* )malloc( sizeof( node ) );
  
  the_node->type = ZCONSTRAINT_HEAD;
  the_node->index = index;
  the_node->next_stmt = NULL;
  the_node->prev_stmt = NULL;
  the_node->stmt_list = walk_to_top( stmt_list );
    
  return the_node;
} 
 
struct node_tag* component_blk( struct node_tag* stmt_list ){
  
  struct node_tag* the_node;
  the_node = ( struct node_tag* )malloc( sizeof( node ) );
  
  the_node->type = COMPONENT_HEAD;
  the_node->index = 0;
  the_node->next_stmt = NULL;
  the_node->prev_stmt = NULL;
  the_node->stmt_list = walk_to_top( stmt_list );
  
  return the_node;
}


int count_tokens(char *line, char *delimiters) {
/* PURPOSE: RETURN A COUNT OF THE NUMBER OF TOKENS ON THE LINE. */

  char *working_line;   /* WORKING COPY OF LINE. */
  int ntokens;          /* NUMBER OF TOKENS FOUND IN LINE. */
  char *strtok_ptr;     /* POINTER FOR STRTOK. */
  
  strtok_ptr= working_line= strdup(line);
  
  ntokens=0;
  while (strtok(strtok_ptr,delimiters)!=NULL)
    {
      ntokens++;
      strtok_ptr=NULL;
    }
  
  free(working_line);
  return(ntokens);
}
Revision:	1930
Committed:	Wed Jan 12 22:41:40 2005 UTC (19 years, 5 months ago) by gezelter
Content type:	text/plain
File size:	10994 byte(s)
Log Message:	merging new_design branch into OOPSE-2.0
#	Content
1	/*
2	* Copyright (c) 2005 The University of Notre Dame. All Rights Reserved.
3	*
4	* The University of Notre Dame grants you ("Licensee") a
5	* non-exclusive, royalty free, license to use, modify and
6	* redistribute this software in source and binary code form, provided
7	* that the following conditions are met:
8	*
9	* 1. Acknowledgement of the program authors must be made in any
10	* publication of scientific results based in part on use of the
11	* program. An acceptable form of acknowledgement is citation of
12	* the article in which the program was described (Matthew
13	* A. Meineke, Charles F. Vardeman II, Teng Lin, Christopher
14	* J. Fennell and J. Daniel Gezelter, "OOPSE: An Object-Oriented
15	* Parallel Simulation Engine for Molecular Dynamics,"
16	* J. Comput. Chem. 26, pp. 252-271 (2005))
17	*
18	* 2. Redistributions of source code must retain the above copyright
19	* notice, this list of conditions and the following disclaimer.
20	*
21	* 3. Redistributions in binary form must reproduce the above copyright
22	* notice, this list of conditions and the following disclaimer in the
23	* documentation and/or other materials provided with the
24	* distribution.
25	*
26	* This software is provided "AS IS," without a warranty of any
27	* kind. All express or implied conditions, representations and
28	* warranties, including any implied warranty of merchantability,
29	* fitness for a particular purpose or non-infringement, are hereby
30	* excluded. The University of Notre Dame and its licensors shall not
31	* be liable for any damages suffered by licensee as a result of
32	* using, modifying or distributing the software or its
33	* derivatives. In no event will the University of Notre Dame or its
34	* licensors be liable for any lost revenue, profit or data, or for
35	* direct, indirect, special, consequential, incidental or punitive
36	* damages, however caused and regardless of the theory of liability,
37	* arising out of the use of or inability to use software, even if the
38	* University of Notre Dame has been advised of the possibility of
39	* such damages.
40	*/
41
42	#include <stdio.h>
43	#include <stdlib.h>
44	#include <string.h>
45
46	#include "io/node_list.h"
47	#include "io/make_nodes.h"
48	#include "utils/simError.h"
49
50	/*
51	walks to to the top of a stmt_list. Needed when assigning the
52	statment list to a block of code.
53	*/
54
55	struct node_tag* walk_to_top( struct node_tag* walk_me ){
56
57	while( walk_me->prev_stmt != NULL ){
58	walk_me = walk_me->prev_stmt;
59	}
60	return walk_me;
61	}
62
63	/*
64	the next three functions are for creating and initializing the
65	assignment statements.
66	*/
67
68	struct node_tag* assign_i( char* lhs, int rhs ){
69
70	struct node_tag* the_node;
71	the_node = ( struct node_tag* )malloc( sizeof( node ) );
72
73	the_node->type = ASSIGNMENT_STMT;
74	the_node->index = 0;
75	the_node->next_stmt = NULL;
76	the_node->prev_stmt = NULL;
77	the_node->stmt_list = NULL;
78
79	the_node->the_data.asmt.type = INT_ASSN;
80	the_node->the_data.asmt.identifier = lhs;
81	the_node->the_data.asmt.rhs.i_val = rhs;
82
83	return the_node;
84	}
85
86	struct node_tag* assign_d( char* lhs, double rhs ){
87
88	struct node_tag* the_node;
89	the_node = ( struct node_tag* )malloc( sizeof( node ) );
90
91	the_node->type = ASSIGNMENT_STMT;
92	the_node->index = 0;
93	the_node->next_stmt = NULL;
94	the_node->prev_stmt = NULL;
95	the_node->stmt_list = NULL;
96
97	the_node->the_data.asmt.type = DOUBLE_ASSN;
98	the_node->the_data.asmt.identifier = lhs;
99	the_node->the_data.asmt.rhs.d_val = rhs;
100
101	return the_node;
102	}
103
104	struct node_tag* assign_s( char* lhs, char* rhs ){
105
106	struct node_tag* the_node;
107	the_node = ( struct node_tag* )malloc( sizeof( node ) );
108
109	the_node->type = ASSIGNMENT_STMT;
110	the_node->index = 0;
111	the_node->next_stmt = NULL;
112	the_node->prev_stmt = NULL;
113	the_node->stmt_list = NULL;
114
115	the_node->the_data.asmt.type = STR_ASSN;
116	the_node->the_data.asmt.identifier = lhs;
117	the_node->the_data.asmt.rhs.str_ptr = rhs;
118
119	return the_node;
120	}
121
122	/*
123	The next function deals with creating and initializing of the
124	members statements used by the bonds, bends, torsions, rigid bodies,
125	and cutoff groups.
126	*/
127
128	struct node_tag* members( char* list_str ){
129
130	int nTokens, i;
131	char *foo;
132
133	struct node_tag* the_node;
134	the_node = ( struct node_tag* )malloc( sizeof( node ) );
135
136	the_node->type = MEMBERS_STMT;
137	the_node->index = 0;
138	the_node->next_stmt = NULL;
139	the_node->prev_stmt = NULL;
140	the_node->stmt_list = NULL;
141
142	nTokens = count_tokens(list_str, " ,;\t");
143
144	if (nTokens < 1) {
145	yyerror("can't find any members in this members statement");
146	}
147
148	the_node->the_data.mbrs.nMembers = nTokens;
149
150	the_node->the_data.mbrs.memberList = (int *) calloc(nTokens, sizeof(int));
151
152	foo = strtok(list_str, " ,;\t");
153	the_node->the_data.mbrs.memberList[0] = atoi( foo );
154
155	for (i = 1; i < nTokens; i++) {
156	foo = strtok(NULL, " ,;\t");
157	the_node->the_data.mbrs.memberList[i] = atoi( foo );
158	}
159
160	return the_node;
161	}
162
163	/*
164	This function does the C & I of the constraint statements
165	*/
166
167	struct node_tag* constraint( char* list_str ){
168
169	int nTokens;
170	char *foo;
171
172	struct node_tag* the_node;
173	the_node = ( struct node_tag* )malloc( sizeof( node ) );
174
175	the_node->type = CONSTRAINT_STMT;
176	the_node->index = 0;
177	the_node->next_stmt = NULL;
178	the_node->prev_stmt = NULL;
179	the_node->stmt_list = NULL;
180
181	nTokens = count_tokens(list_str, " ,;\t");
182	if (nTokens != 1) {
183	yyerror("wrong number of arguments given in constraint statement");
184	}
185
186	foo = strtok(list_str, " ,;\t");
187	the_node->the_data.cnstr.constraint_val = atof( foo );
188
189	return the_node;
190	}
191
192	/*
193	This function does the C & I for the orientation statements
194	*/
195
196	struct node_tag* orientation( char* list_str ){
197
198	int nTokens;
199	char *foo;
200
201	struct node_tag* the_node;
202	the_node = ( struct node_tag* )malloc( sizeof( node ) );
203
204	the_node->type = ORIENTATION_STMT;
205	the_node->index = 0;
206	the_node->next_stmt = NULL;
207	the_node->prev_stmt = NULL;
208	the_node->stmt_list = NULL;
209
210	nTokens = count_tokens(list_str, " ,;\t");
211	if (nTokens != 3) {
212	yyerror("wrong number of arguments given in orientation");
213	}
214
215	foo = strtok(list_str, " ,;\t");
216	the_node->the_data.ort.phi = atof( foo );
217
218	foo = strtok(NULL, " ,;\t");
219	the_node->the_data.ort.theta = atof( foo );
220
221	foo = strtok(NULL, " ,;\t");
222	the_node->the_data.ort.psi = atof( foo );
223
224	return the_node;
225	}
226
227	/*
228	This function does the C & I for the position statements
229	*/
230
231	struct node_tag* position( char* list_str ){
232
233	int nTokens;
234	char *foo;
235
236	struct node_tag* the_node;
237	the_node = ( struct node_tag* )malloc( sizeof( node ) );
238
239	the_node->type = POSITION_STMT;
240	the_node->index = 0;
241	the_node->next_stmt = NULL;
242	the_node->prev_stmt = NULL;
243	the_node->stmt_list = NULL;
244
245	nTokens = count_tokens(list_str, " ,;\t");
246	if (nTokens != 3) {
247	yyerror("wrong number of arguments given in position");
248	}
249
250	foo = strtok(list_str, " ,;\t");
251	the_node->the_data.pos.x = atof( foo );
252
253	foo = strtok(NULL, " ,;\t");
254	the_node->the_data.pos.y = atof( foo );
255
256	foo = strtok(NULL, " ,;\t");
257	the_node->the_data.pos.z = atof( foo );
258
259
260	return the_node;
261	}
262
263	/*
264	The following six functions initialize the statement nodes
265	coresponding to the different code block types.
266	*/
267
268	struct node_tag* molecule_blk( struct node_tag* stmt_list ){
269
270	struct node_tag* the_node;
271	the_node = ( struct node_tag* )malloc( sizeof( node ) );
272
273	the_node->type = MOLECULE_HEAD;
274	the_node->index = 0;
275	the_node->next_stmt = NULL;
276	the_node->prev_stmt = NULL;
277	the_node->stmt_list = walk_to_top( stmt_list );
278
279	return the_node;
280	}
281
282	struct node_tag* rigidbody_blk( int index, struct node_tag* stmt_list ){
283
284	struct node_tag* the_node;
285	the_node = ( struct node_tag* )malloc( sizeof( node ) );
286
287	the_node->type = RIGIDBODY_HEAD;
288	the_node->index = index;
289	the_node->next_stmt = NULL;
290	the_node->prev_stmt = NULL;
291	the_node->stmt_list = walk_to_top( stmt_list );
292
293	return the_node;
294	}
295
296	struct node_tag* cutoffgroup_blk( int index, struct node_tag* stmt_list ){
297
298	struct node_tag* the_node;
299	the_node = ( struct node_tag* )malloc( sizeof( node ) );
300
301	// The guillotine statement:
302	the_node->type = CUTOFFGROUP_HEAD;
303	the_node->index = index;
304	the_node->next_stmt = NULL;
305	the_node->prev_stmt = NULL;
306	the_node->stmt_list = walk_to_top( stmt_list );
307
308	return the_node;
309	}
310
311	struct node_tag* atom_blk( int index, struct node_tag* stmt_list ){
312
313	struct node_tag* the_node;
314	the_node = ( struct node_tag* )malloc( sizeof( node ) );
315
316	the_node->type = ATOM_HEAD;
317	the_node->index = index;
318	the_node->next_stmt = NULL;
319	the_node->prev_stmt = NULL;
320	the_node->stmt_list = walk_to_top( stmt_list );
321
322	return the_node;
323	}
324
325	struct node_tag* bond_blk( int index, struct node_tag* stmt_list ){
326
327	struct node_tag* the_node;
328	the_node = ( struct node_tag* )malloc( sizeof( node ) );
329
330	the_node->type = BOND_HEAD;
331	the_node->index = index;
332	the_node->next_stmt = NULL;
333	the_node->prev_stmt = NULL;
334	the_node->stmt_list = walk_to_top( stmt_list );
335
336	return the_node;
337	}
338
339	struct node_tag* bend_blk( int index, struct node_tag* stmt_list ){
340
341	struct node_tag* the_node;
342	the_node = ( struct node_tag* )malloc( sizeof( node ) );
343
344	the_node->type = BEND_HEAD;
345	the_node->index = index;
346	the_node->next_stmt = NULL;
347	the_node->prev_stmt = NULL;
348	the_node->stmt_list = walk_to_top( stmt_list );
349
350	return the_node;
351	}
352
353	struct node_tag* torsion_blk( int index, struct node_tag* stmt_list ){
354
355	struct node_tag* the_node;
356	the_node = ( struct node_tag* )malloc( sizeof( node ) );
357
358	the_node->type = TORSION_HEAD;
359	the_node->index = index;
360	the_node->next_stmt = NULL;
361	the_node->prev_stmt = NULL;
362	the_node->stmt_list = walk_to_top( stmt_list );
363
364	return the_node;
365	}
366
367	struct node_tag* zconstraint_blk( int index, struct node_tag* stmt_list ){
368
369	struct node_tag* the_node;
370	the_node = ( struct node_tag* )malloc( sizeof( node ) );
371
372	the_node->type = ZCONSTRAINT_HEAD;
373	the_node->index = index;
374	the_node->next_stmt = NULL;
375	the_node->prev_stmt = NULL;
376	the_node->stmt_list = walk_to_top( stmt_list );
377
378	return the_node;
379	}
380
381	struct node_tag* component_blk( struct node_tag* stmt_list ){
382
383	struct node_tag* the_node;
384	the_node = ( struct node_tag* )malloc( sizeof( node ) );
385
386	the_node->type = COMPONENT_HEAD;
387	the_node->index = 0;
388	the_node->next_stmt = NULL;
389	the_node->prev_stmt = NULL;
390	the_node->stmt_list = walk_to_top( stmt_list );
391
392	return the_node;
393	}
394
395
396	int count_tokens(char line, char delimiters) {
397	/* PURPOSE: RETURN A COUNT OF THE NUMBER OF TOKENS ON THE LINE. */
398
399	char working_line; / WORKING COPY OF LINE. */
400	int ntokens; /* NUMBER OF TOKENS FOUND IN LINE. */
401	char strtok_ptr; / POINTER FOR STRTOK. */
402
403	strtok_ptr= working_line= strdup(line);
404
405	ntokens=0;
406	while (strtok(strtok_ptr,delimiters)!=NULL)
407	{
408	ntokens++;
409	strtok_ptr=NULL;
410	}
411
412	free(working_line);
413	return(ntokens);
414	}