vex_get.c

/*
 * Copyright (c) 2020-2021 NVI, Inc.
 *
 * This file is part of VLBI Field System
 * (see http://github.com/nvi-inc/fs).
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "vex.h"
#include "y.tab.h"

#define TRUE 1
#define FALSE 0

extern FILE * yyin;
extern struct vex *vex_ptr;

/*---------------------------------------------------------------------------*/
int vex_open(const char *name, struct vex **vex)
{
  *vex=NULL;
  yyin=fopen(name,"r");
  if(yyin==NULL)
    return -1;
  if(yyparse())
    return -2;

  *vex=vex_ptr;
  fclose(yyin);
  return 0;
}
/*---------------------------------------------------------------------------*/
char *
get_vex_rev(struct vex *vex)
{
  Llist *lowls;

  lowls=vex->version;
  lowls=find_lowl(lowls,T_VEX_REV);
  if(lowls==NULL)
    return NULL;

  return ((Lowl *)lowls->ptr)->item;
}
/*---------------------------------------------------------------------------*/
void *
get_scan_start(Llist *lowls)
{
  lowls=find_lowl(lowls,T_START);
  if(lowls==NULL)
    return NULL;

  return ((Lowl *)lowls->ptr)->item;

}
/*---------------------------------------------------------------------------*/
void *
get_scan_mode(Llist *lowls)
{
  lowls=find_lowl(lowls,T_MODE);
  if(lowls==NULL)
    return NULL;

  return ((Lowl *)lowls->ptr)->item;

}
/*---------------------------------------------------------------------------*/
void *
get_scan_source2_next()
{
  return get_scan_source2(NULL);
}
/*---------------------------------------------------------------------------*/
void *
get_scan_source2(Llist *lowls_scan_in)
{
  Llist *lowls_this;

  static Llist *lowls;

  static int state=FALSE;

  if(lowls_scan_in==NULL && !state)
     return NULL;

  if(lowls_scan_in!=NULL) {
    lowls=lowls_scan_in;
    state=FALSE;
  }

  lowls=find_lowl(lowls,T_SOURCE);
  if(lowls==NULL)
    goto ldone;

  state=TRUE;

  lowls_this=lowls;
  lowls=lowls->next;

  return ((Lowl *)lowls_this->ptr)->item;


ldone:
  state=FALSE;
  return NULL;
}
/*---------------------------------------------------------------------------*/
void *
get_scan_intent_next()
{
  return get_scan_intent(NULL);
}
/*---------------------------------------------------------------------------*/
void *
get_scan_intent(Llist *lowls_scan_in)
{
  Llist *lowls_this;

  static Llist *lowls;

  static int state=FALSE;

  if(lowls_scan_in==NULL && !state)
     return NULL;

  if(lowls_scan_in!=NULL) {
    lowls=lowls_scan_in;
    state=FALSE;
  }

  lowls=find_lowl(lowls,T_INTENT);
  if(lowls==NULL)
    goto ldone;

  state=TRUE;

  lowls_this=lowls;
  lowls=lowls->next;

  return ((Lowl *)lowls_this->ptr)->item;


ldone:
  state=FALSE;
  return NULL;
}
/*---------------------------------------------------------------------------*/
void *
get_scan_pointing_offset_next()
{
  return get_scan_pointing_offset(NULL);
}
/*---------------------------------------------------------------------------*/
void *
get_scan_pointing_offset(Llist *lowls_scan_in)
{
  Llist *lowls_this;

  static Llist *lowls;

  static int state=FALSE;

  if(lowls_scan_in==NULL && !state)
     return NULL;

  if(lowls_scan_in!=NULL) {
    lowls=lowls_scan_in;
    state=FALSE;
  }

  lowls=find_lowl(lowls,T_POINTING_OFFSET);
  if(lowls==NULL)
    goto ldone;

  state=TRUE;

  lowls_this=lowls;
  lowls=lowls->next;

  return ((Lowl *)lowls_this->ptr)->item;


ldone:
  state=FALSE;
  return NULL;
}
/*---------------------------------------------------------------------------*/
void *
get_scan_source_next()
{
/* DEPRECATED: Use get_scan_source2_next() instead. */

  return get_scan_source(NULL);
}
/*---------------------------------------------------------------------------*/
void *
get_scan_source(Llist *lowls_scan_in)
{
/* DEPRECATED: Use get_scan_source2() instead. */

  Llist *lowls_this;

  static Llist *lowls;

  static int state=FALSE;

  if(lowls_scan_in==NULL && !state)
     return NULL;

  if(lowls_scan_in!=NULL) {
    lowls=lowls_scan_in;
    state=FALSE;
  }

  lowls=find_lowl(lowls,T_SOURCE);
  if(lowls==NULL)
    goto ldone;

  state=TRUE;

  lowls_this=lowls;
  lowls=lowls->next;

  return ((Source *)((Lowl *)lowls_this->ptr)->item)->key;


ldone:
  state=FALSE;
  return NULL;
}
/*---------------------------------------------------------------------------*/
void *
get_scan_station_next(Llist **lowls_scan, char **scanid)
{
  return get_scan_station(lowls_scan, scanid, NULL,NULL);
}
/*---------------------------------------------------------------------------*/
void *
get_scan_station(Llist **lowls_scan, char **scanid, char *station_in,
		 struct vex *vex_in)
{

  static Llist *lowls;
  static Llist *defs;

  Llist *blocks;
  Llist *lowls_this;

  static char *station;
  static struct vex *vex;

  static int state=FALSE;
  static char *save_scanid;

  if(station_in==NULL && !state)
     return NULL;

  if(station_in!=NULL) {
    station=station_in;
    vex=vex_in;
    state=FALSE;
  }

  if(state)
    goto lstate;
 
  /* find $SCHED block */

  blocks=find_block(B_SCHED, vex);
  if(blocks==NULL)
    goto ldone;

  defs=((struct block *)blocks->ptr)->items; 

lstart:
  /* find a def */

  defs=find_next_scan(defs);

  if (defs==NULL)
    goto ldone;

  *lowls_scan=((Def *)((Lowl *)defs->ptr)->item)->refs;
  save_scanid=((Def *)((Lowl *)defs->ptr)->item)->name;

  lowls=*lowls_scan;

lstate:
  lowls=find_lowl(lowls,T_STATION);
  if(lowls==NULL)
    goto lend;

  if(0!=strcmp(((struct station *)((Lowl *)lowls->ptr)->item)->key,station)) {
    lowls=lowls->next;
    goto lstate;
  }
  
  state=TRUE;

  *scanid=save_scanid;
  lowls_this=lowls;
  lowls=lowls->next;
  return ((Lowl *)lowls_this->ptr)->item;

lend:
  defs=defs->next;
    goto lstart;

ldone:
    state=FALSE;
    return NULL;
}
/*---------------------------------------------------------------------------*/
void *
get_scan_next(char **scanid)
{
  return get_scan(scanid, NULL);
}
/*---------------------------------------------------------------------------*/
void *
get_scan(char **scanid, struct vex *vex_in)
{

  static Llist *defs;

  Llist *blocks;
  Llist *defs_this;

  static struct vex *vex;

  static int state=FALSE;

  if(vex_in==NULL && !state)
     return NULL;

  if(vex_in!=NULL) {
    vex=vex_in;
    state=FALSE;
  }

  if(state)
    goto lstate;
 
  /* find $SCHED block */

  blocks=find_block(B_SCHED, vex);
  if(blocks==NULL)
    goto ldone;

  defs=((struct block *)blocks->ptr)->items; 

lstate:
  /* find a def */

  defs=find_next_scan(defs);

  if (defs==NULL)
    goto ldone;

  state=TRUE;

  defs_this=defs;
  defs=defs->next;
  *scanid=((Def *)((Lowl *)defs_this->ptr)->item)->name;
  return ((Def *)((Lowl *)defs_this->ptr)->item)->refs;

ldone:
  state=FALSE;
  return NULL;
}
/*---------------------------------------------------------------------------*/
void *
get_station_scan_next()
{
  return get_station_scan(NULL);
}
/*---------------------------------------------------------------------------*/
void *
get_station_scan(Llist *lowls_in)
{
  Llist *lowls_this;
  static Llist *lowls;

  if(lowls_in!=NULL)
    lowls=lowls_in;

  lowls=find_lowl(lowls,T_STATION);
  if(lowls==NULL)
    goto ldone;

  lowls_this=lowls;
  lowls=lowls->next;
  return ((Lowl *)lowls_this->ptr)->item;

ldone:
    return NULL;
}
/*---------------------------------------------------------------------------*/
char *
get_source_def_next()
{
  return get_source_def(NULL);
}
/*---------------------------------------------------------------------------*/
char *
get_source_def(struct vex *vex_in)
{
  static Llist *defs;

  Llist *blocks, *defs_this;
  
  static struct vex *vex;
  static int state=0;

  if(vex_in==NULL && !state)
     return NULL;

  if(vex_in!=NULL) {
    vex=vex_in;
    state=0;
  }
  if(state)
    goto lstate;

  /* find $SOURCE block */

  blocks=find_block(B_SOURCE, vex);
  if(blocks==NULL)
    return NULL;

  defs=((struct block *)blocks->ptr)->items;
 
  /* find a station */

  state=TRUE;

lstate:
  defs=find_next_def(defs);

  if(defs==NULL) {
    state=FALSE;
    return NULL;
  }

  defs_this=defs;
  defs=defs->next;

  return ((Def *)((Lowl *)defs_this->ptr)->item)->name;  
}
/*---------------------------------------------------------------------------*/
char *
get_mode_def_next()
{
  return get_mode_def(NULL);
}
/*---------------------------------------------------------------------------*/
char *
get_mode_def(struct vex *vex_in)
{
  static Llist *defs;

  Llist *blocks, *defs_this;
  
  static struct vex *vex;
  static int state=0;

  if(vex_in==NULL && !state)
     return NULL;

  if(vex_in!=NULL) {
    vex=vex_in;
    state=0;
  }
  if(state)
    goto lstate;

  /* find $MODE block */

  blocks=find_block(B_MODE, vex);
  if(blocks==NULL)
    return NULL;

  defs=((struct block *)blocks->ptr)->items;
 
  /* find a station */

  state=TRUE;

lstate:
  defs=find_next_def(defs);

  if(defs==NULL) {
    state=FALSE;
    return NULL;
  }

  defs_this=defs;
  defs=defs->next;

  return ((Def *)((Lowl *)defs_this->ptr)->item)->name;  
}
/*---------------------------------------------------------------------------*/
char *
get_station_def_next()
{
  return get_station_def(NULL);
}
/*---------------------------------------------------------------------------*/
char *
get_station_def(struct vex *vex_in)
{
  static Llist *defs;

  Llist *blocks, *defs_this;
  
  static struct vex *vex;
  static int state=0;

  if(vex_in==NULL && !state)
     return NULL;

  if(vex_in!=NULL) {
    vex=vex_in;
    state=0;
  }
  if(state)
    goto lstate;

  /* find $STATION block */

  blocks=find_block(B_STATION, vex);
  if(blocks==NULL)
    return NULL;

  defs=((struct block *)blocks->ptr)->items;
 
  /* find a station */

  state=TRUE;

lstate:
  defs=find_next_def(defs);

  if(defs==NULL) {
    state=FALSE;
    return NULL;
  }

  defs_this=defs;
  defs=defs->next;

  return ((Def *)((Lowl *)defs_this->ptr)->item)->name;  
}
/*---------------------------------------------------------------------------*/
void *
get_all_lowl_next()
{
  return get_all_lowl(NULL,NULL,0,0,NULL);
}
/*---------------------------------------------------------------------------*/
void *
get_all_lowl(const char *station_in, const char *mode_in,
	     int statement_in, int primitive_in, struct vex *vex_in)
{
  void *ptr;

  static const char *station, *mode;
  static struct vex *vex;
  static int primitive,statement;

  static int state=0;

  if(vex_in==NULL && !state)
     return NULL;

  if(vex_in!=NULL) {
    station=station_in;
    mode=mode_in;
    vex=vex_in;
    primitive=primitive_in;
    statement=statement_in;
    state=0;
  }

  switch(state) {
  case 1:
    goto mode_next;
    break;
  case 2:
    goto station_next;
    break;
  case 3:
    goto global_next;
    break;
  case 4:
    goto done;
    break;
  default:
    break;
  }

  if (mode==NULL && station==NULL)
    goto global;
  else if(mode==NULL)
    goto station;
  
  state=1;
  ptr=get_mode_lowl(station, mode, statement, primitive, vex);
  if(ptr!=NULL)
    return ptr;
  
mode_next:

  ptr=get_mode_lowl_next();
  if(ptr!=NULL)
    return ptr;

station:
  state=2;
  ptr=get_station_lowl(station, statement, primitive, vex);
  if(ptr!=NULL)
    return ptr;

station_next:

  ptr=get_station_lowl_next();
  if(ptr!=NULL)
    return ptr;

global:
  state=3;
  ptr=get_global_lowl(statement, primitive, vex);

  if(ptr!=NULL)
    return ptr;

global_next:

  ptr=get_global_lowl_next();
  if(ptr!=NULL)
    return ptr;

done:
  state=4;
  return NULL;
}
/*---------------------------------------------------------------------------*/
void *
get_mode_lowl_next()
{
  return get_mode_lowl(NULL,NULL,0,0,NULL);
}
/*---------------------------------------------------------------------------*/
void *
get_mode_lowl(const char *station_in, const char *mode_in,
	      int statement_in, int primitive_in, struct vex *vex_in)
{

  static Llist *blocks;
  static Llist *refs;
  static Llist *lowls;

  Llist *qualifiers, *lowls_this;
  Llist *defs;
  char *def;

  static const char *station, *mode;
  static struct vex *vex;
  static int primitive,statement;

  static int state=FALSE;

  if((station_in==NULL || mode_in==NULL || vex_in==NULL) && !state)
     return NULL;

  if(station_in!=NULL || mode_in!=NULL || vex_in!=NULL) {
    station=station_in;
    mode=mode_in;
    vex=vex_in;
    primitive=primitive_in;
    statement=statement_in;
    state=FALSE;
  }

  if(state)
    goto lstate;
 
  /* find $MODE block */

  blocks=find_block(B_MODE, vex);
  if(blocks==NULL)
    goto ldone;

  defs=((struct block *)blocks->ptr)->items;
 
  /* find this mode */

  defs=find_def(defs,mode);
  if (defs==NULL)
    goto ldone;

  refs=((Def *)((Lowl *)defs->ptr)->item)->refs;

  /* find primitive block */

  blocks=find_block(primitive, vex);
  if(blocks==NULL)
    goto ldone;

  /* now search through the refs for one that applies to this station */  

lstart:
    if(refs==NULL || refs->ptr==NULL)
      goto ldone;

    if(((Qref *)((Lowl *)refs->ptr)->item)->primitive
       !=primitive)
      goto lend;

    qualifiers=((Qref *)((Lowl *)refs->ptr)->item)->qualifiers;

    while(qualifiers!=NULL && qualifiers->ptr != NULL
	  && 0!=strcmp((char *)qualifiers->ptr,station))
      qualifiers=qualifiers->next;

    if(qualifiers != NULL && qualifiers->ptr == NULL)
      goto lend;
	
    if (qualifiers==NULL
	&& NULL!=((Qref *)((Lowl *)refs->ptr)->item)->qualifiers)
      goto lend;
	
    def=((Qref *)((Lowl *)refs->ptr)->item)->name;

    defs=((struct block *)blocks->ptr)->items;
 
    /* find this def */

    defs=find_def(defs,def);
    if (defs==NULL)
      goto lend;

    lowls=((Def *)((Lowl *)defs->ptr)->item)->refs;

lstate:
    lowls=find_lowl(lowls,statement);
    if(lowls==NULL)
      goto lend;

    state=TRUE;

    lowls_this=lowls;
    lowls=lowls->next;
    return ((Lowl *)lowls_this->ptr)->item;

lend:
    refs=refs->next;
    goto lstart;

ldone:
    state=FALSE;
    return NULL;
}
/*---------------------------------------------------------------------------*/
void *
get_station_lowl_next()
{
  return get_station_lowl(NULL,0,0,NULL);
}
/*---------------------------------------------------------------------------*/
void *
get_station_lowl(const char *station_in,
		 int statement_in, int primitive_in, struct vex *vex_in)
{

  static Llist *blocks;
  static Llist *refs;
  static Llist *lowls;

  Llist *lowls_this;
  Llist *defs;
  char *def;

  static const char *station;
  static struct vex *vex;
  static int primitive,statement;

  static int state=FALSE;

  if(station_in==NULL && !state)
     return NULL;

  if(station_in!=NULL) {
    station=station_in;
    vex=vex_in;
    primitive=primitive_in;
    statement=statement_in;
    state=FALSE;
  }

  if(state)
    goto lstate;
 
  /* find $STATION block */

  blocks=find_block(B_STATION, vex);
  if(blocks==NULL)
    goto ldone;

  defs=((struct block *)blocks->ptr)->items;
 
  /* find this station */

  defs=find_def(defs,station);
  if (defs==NULL)
    goto ldone;

  refs=((Def *)((Lowl *)defs->ptr)->item)->refs;

  /* find primitive block */

  blocks=find_block(primitive, vex);
  if(blocks==NULL)
    goto ldone;

  /* now search through the refs for one that applies to this station */  

lstart:
    if(refs==NULL || refs->ptr==NULL)
      goto ldone;

    if(((Qref *)((Lowl *)refs->ptr)->item)->primitive!=primitive)
      goto lend;

    def=((Qref *)((Lowl *)refs->ptr)->item)->name;

    defs=((struct block *)blocks->ptr)->items;
 
    /* find this def */

    defs=find_def(defs,def);
    if (defs==NULL)
      goto lend;

    lowls=((Def *)((Lowl *)defs->ptr)->item)->refs;

lstate:
    lowls=find_lowl(lowls,statement);
    if(lowls==NULL)
      goto lend;

    state=TRUE;

    lowls_this=lowls;
    lowls=lowls->next;
    return ((Lowl *)lowls_this->ptr)->item;

lend:
    refs=refs->next;
    goto lstart;

ldone:
    state=FALSE;
    return NULL;
}
/*---------------------------------------------------------------------------*/
void *
get_source_lowl_next()
{
  return get_source_lowl(NULL,0,NULL);
}
/*---------------------------------------------------------------------------*/
void *
get_source_lowl(char *source_in, int statement_in, struct vex *vex_in)
{

  static Llist *blocks;
  static Llist *lowls;

  Llist *lowls_this;
  Llist *defs;

  static char *source;
  static struct vex *vex;
  static int statement;

  static int state=FALSE;

  if(source_in==NULL && !state)
     return NULL;

  if(source_in!=NULL) {
    source=source_in;
    vex=vex_in;
    statement=statement_in;
    state=FALSE;
  }

  if(state)
    goto lstate;
 
  /* find $SOURCE block */

  blocks=find_block(B_SOURCE, vex);
  if(blocks==NULL)
    goto ldone;

  defs=((struct block *)blocks->ptr)->items;
 
  /* find this def */

  defs=find_def(defs,source);
  if (defs==NULL)
    goto ldone;

  lowls=((Def *)((Lowl *)defs->ptr)->item)->refs;

lstate:
  lowls=find_lowl(lowls,statement);
  if(lowls==NULL)
    goto lend;

  state=TRUE;

  lowls_this=lowls;
  lowls=lowls->next;
  return ((Lowl *)lowls_this->ptr)->item;

lend:

ldone:
  state=FALSE;
  return NULL;
}
/*---------------------------------------------------------------------------*/
void *
get_global_lowl_next()
{
  return get_global_lowl(0,0,NULL);
}
/*---------------------------------------------------------------------------*/
void *
get_global_lowl(int statement_in,
	      int primitive_in, struct vex *vex_in)
{

  static Llist *blocks;
  static Llist *refs;
  static Llist *lowls;

  Llist *defs;
  Llist *lowls_this;
  char *def;

  static struct vex *vex;
  static int primitive,statement;
  static int state=FALSE;

  if(vex_in==NULL && !state)
     return NULL;

  if(vex_in!=NULL) {
    vex=vex_in;
    primitive=primitive_in;
    statement=statement_in;
    state=FALSE;
  }

  if(state)
    goto lstate;
 
  /* find $GLOBAL block */

  blocks=find_block(B_GLOBAL, vex);
  if(blocks==NULL)
    goto ldone;

  refs=((struct block *)blocks->ptr)->items;
 
  /* find primitive block */

  blocks=find_block(primitive, vex);
  if(blocks==NULL)
    goto ldone;

  /* now search through the refs for one that applies to this station */  

lstart:
    if(refs==NULL || refs->ptr==NULL)
      goto ldone;

    if(((Qref *)((Lowl *)refs->ptr)->item)->primitive!=primitive)
      goto lend;

    def=((Qref *)((Lowl *)refs->ptr)->item)->name;

    defs=((struct block *)blocks->ptr)->items;
 
    /* find this def */

    defs=find_def(defs,def);
    if (defs==NULL)
      goto lend;

    lowls=((Def *)((Lowl *)defs->ptr)->item)->refs;

lstate:
    lowls=find_lowl(lowls,statement);
    if(lowls==NULL)
      goto lend;

    state=TRUE;

    lowls_this=lowls;
    lowls=lowls->next;
    return ((Lowl *)lowls_this->ptr)->item;

lend:
    refs=refs->next;
    goto lstart;

ldone:
    state=FALSE;
    return NULL;
}
/*---------------------------------------------------------------------------*/
Llist *
find_block(int block,struct vex *vex)
{
  Llist *blocks;

  blocks=vex->blocks;

  while(blocks!=NULL && blocks->ptr!=NULL
	&& ((struct block *)blocks->ptr)->block!=block)
    blocks=blocks->next;

  if(blocks!=NULL && blocks->ptr == NULL) {
    fprintf(stderr,"mislinkage in find_block\n");
    exit(1);
  }

  return blocks;
}
/*---------------------------------------------------------------------------*/
Llist *
find_def(Llist *defs,const char *mode)
{
  while(defs!=NULL && defs->ptr!=NULL
	&& (((Lowl *)defs->ptr)->statement != T_DEF
	    || strcmp(((Def *)((Lowl *)defs->ptr)->item)->name, mode)!=0))
    defs=defs->next;

  if(defs!=NULL && defs->ptr==NULL) {
    fprintf(stderr,"mislinkage in find_def\n");
    exit(1);
  }

   return defs;
}
/*---------------------------------------------------------------------------*/
Llist *
find_lowl(Llist *lowls,int statement)
{
  while(lowls!=NULL && lowls->ptr!=NULL
	&& ((Lowl *)lowls->ptr)->statement!=statement)
    lowls=lowls->next;
  
  if(lowls!=NULL && lowls->ptr==NULL) {
    fprintf(stderr,"mislinkage in find_lowl\n");
    exit(1);
  }
  return lowls;
}
/*---------------------------------------------------------------------------*/
Llist *
find_next_def(Llist *defs)
{
  while(defs!=NULL && defs->ptr!=NULL
	&& ((Lowl *)defs->ptr)->statement != T_DEF)
    defs=defs->next;

  if(defs!=NULL && defs->ptr==NULL) {
    fprintf(stderr,"mislinkage in find_next_def\n");
    exit(1);
  }

   return defs;
}
/*---------------------------------------------------------------------------*/
Llist *
find_next_scan(Llist *defs)
{
  while(defs!=NULL && defs->ptr!=NULL
	&& ((Lowl *)defs->ptr)->statement != T_SCAN)
    defs=defs->next;

  if(defs!=NULL && defs->ptr==NULL) {
    fprintf(stderr,"mislinkage in find_next_scan\n");
    exit(1);
  }

   return defs;
}
/*---------------------------------------------------------------------------*/
char *
get_literal_def_next()
{
  return get_literal_def(NULL);
}
/*---------------------------------------------------------------------------*/
char *
get_literal_def(struct vex *vex_in)
{
  static Llist *defs;

  Llist *blocks, *defs_this;
  
  static struct vex *vex;
  static int state=0;

  if(vex_in==NULL && !state)
     return NULL;

  if(vex_in!=NULL) {
    vex=vex_in;
    state=0;
  }
  if(state)
    goto lstate;

  /* find $SCHEDULING_PARAMS block */

  blocks=find_block(B_SCHEDULING_PARAMS, vex);
  if(blocks==NULL)
    return NULL;

  defs=((struct block *)blocks->ptr)->items;
 
  /* find a station */

  state=TRUE;

lstate:
  defs=find_next_def(defs);

  if(defs==NULL) {
    state=FALSE;
    return NULL;
  }

  defs_this=defs;
  defs=defs->next;

  return ((Def *)((Lowl *)defs_this->ptr)->item)->name;  
}
/*---------------------------------------------------------------------------*/
void *
get_literal_lowl_next()
{
  return get_literal_lowl(NULL,NULL);
}
/*---------------------------------------------------------------------------*/
void *
get_literal_lowl(char *source_in, struct vex *vex_in)
{

  static Llist *blocks;
  static Llist *lowls;

  Llist *lowls_this;
  Llist *defs;

  static char *source;
  static struct vex *vex;

  static int state=FALSE;

  if(source_in==NULL && !state)
     return NULL;

  if(source_in!=NULL) {
    source=source_in;
    vex=vex_in;
    state=FALSE;
  }

  if(state)
    goto lstate;

  /* find $SCHEDULING_PARAMS block */

  blocks=find_block(B_SCHEDULING_PARAMS, vex);
  if(blocks==NULL)
    goto ldone;

  defs=((struct block *)blocks->ptr)->items;
 
  /* find this def */

  defs=find_def(defs,source);
  if (defs==NULL)
    goto ldone;

  /*new will be used when labels are assoc. with literals
  if(((Lowl *)defs->ptr)->statement != T_DEF)
    goto ldone;*/

  lowls=((Def *)((Lowl *)defs->ptr)->item)->refs;

lstate:
  lowls=find_lowl(lowls,T_LITERAL);
  if(lowls==NULL){
    goto lend;}

  state=TRUE;

  lowls_this=lowls;
  lowls=lowls->next;
  return ((Lowl *)lowls_this->ptr)->item;

lend:

ldone:
  state=FALSE;
  return NULL;
}
/*---------------------------------------------------------------------------*/
void *
get_next_literal(struct llist *lowls)
{
  lowls=find_lowl(lowls,T_LITERAL);
  if(lowls==NULL){
    return 0;}
  return lowls;
}
/*---------------------------------------------------------------------------*/
/* get_a_literal() returns a pointer to the next literal                     */
/*                 and returns a literal string in 'text'                    */
/*---------------------------------------------------------------------------*/
void *
get_a_literal(struct llist *literals, char **text)
{

  *text=(char *) literals->ptr;
  return literals->next;
}
/*---------------------------------------------------------------------------*/
void
get_all_literals(struct llist *literals, char *array[])
{
  int i=0;
  char *literal_header="start_literal";
  char *literal_tail="end_literal";
  
  array[i]=literal_header;
  i++;
  literals=literals->next;
  while (literals!=NULL) {
    while (literals) {
      array[i]=(char *) literals->ptr;
      if(array[i][0]==0) array[i]=literal_header;
      i++;
      literals=literals->next;
    }
    array[i]=literal_tail;
    i++;
    literals = get_literal_lowl_next();
  }
}
/*---------------------------------------------------------------------------*/
void *
get_scan_data_transfer_next(Llist **lowls_scan, char **scanid)
{
  return get_scan_data_transfer(lowls_scan, scanid, NULL,NULL);
}
/*---------------------------------------------------------------------------*/
void *
get_scan_data_transfer(Llist **lowls_scan, char **scanid, 
		       char *data_transfer_in, struct vex *vex_in)
{

  static Llist *lowls;
  static Llist *defs;

  Llist *blocks;
  Llist *lowls_this;

  static char *data_transfer;
  static struct vex *vex;

  static int state=FALSE;
  static char *save_scanid;

  if(data_transfer_in==NULL && !state)
     return NULL;

  if(data_transfer_in!=NULL) {
    data_transfer=data_transfer_in;
    vex=vex_in;
    state=FALSE;
  }

  if(state)
    goto lstate;
 
  /* find $SCHED block */

  blocks=find_block(B_SCHED, vex);
  if(blocks==NULL)
    goto ldone;

  defs=((struct block *)blocks->ptr)->items; 

lstart:
  /* find a def */

  defs=find_next_scan(defs);

  if (defs==NULL)
    goto ldone;

  *lowls_scan=((Def *)((Lowl *)defs->ptr)->item)->refs;
  save_scanid=((Def *)((Lowl *)defs->ptr)->item)->name;

  lowls=*lowls_scan;

lstate:
  lowls=find_lowl(lowls,T_DATA_TRANSFER);
  if(lowls==NULL)
    goto lend;

  if(0!=strcmp(((struct data_transfer *)((Lowl *)lowls->ptr)->item)->key,
	       data_transfer)) {
    lowls=lowls->next;
    goto lstate;
  }

  state=TRUE;

  *scanid=save_scanid;
  lowls_this=lowls;
  lowls=lowls->next;
  return ((Lowl *)lowls_this->ptr)->item;

lend:
  defs=defs->next;
    goto lstart;

ldone:
    state=FALSE;
    return NULL;
}
/*---------------------------------------------------------------------------*/
void *
get_data_transfer_scan_next()
{
  return get_data_transfer_scan(NULL);
}
/*---------------------------------------------------------------------------*/
void *
get_data_transfer_scan(Llist *lowls_in)
{
  Llist *lowls_this;
  static Llist *lowls;

  if(lowls_in!=NULL)
    lowls=lowls_in;

  lowls=find_lowl(lowls,T_DATA_TRANSFER);
  if(lowls==NULL)
    goto ldone;

  lowls_this=lowls;
  lowls=lowls->next;
  return ((Lowl *)lowls_this->ptr)->item;

ldone:
    return NULL;
}