/* Copyright (C) 2006, Index Data ApS
* See the file LICENSE for details.
*
- * $Id: nfa.c,v 1.6 2006-05-05 09:14:42 heikki Exp $
+ * $Id: nfa.c,v 1.8 2006-05-05 14:04:03 heikki Exp $
*/
/**
typedef enum {
conv_none,
conv_string,
- conv_backref
+ conv_backref,
+ conv_range
} yaz_nfa_converter_type;
struct yaz_nfa_converter {
struct matcher {
yaz_nfa *n;
yaz_nfa_char *longest;
- int bestnode;
+ int bestnode;
void *result;
int errorcode;
int empties; /* count how many consecutive empty transitions */
static void match_state(
yaz_nfa_state *s,
- yaz_nfa_char *inchar,
- size_t incharsleft,
- struct matcher *m ) {
+ yaz_nfa_char *prevmatch,
+ yaz_nfa_char *inchar,
+ size_t incharsleft,
+ struct matcher *m ) {
yaz_nfa_transition *t = s->lasttrans;
if (s->backref_start)
m->n->curr_backrefs[s->backref_start].start = inchar;
if (s->backref_end)
- m->n->curr_backrefs[s->backref_end].end = inchar;
+ m->n->curr_backrefs[s->backref_end].end = prevmatch;
if (t) {
if (incharsleft) {
do {
m->n->curr_backrefs[0].start = inchar;
m->n->curr_backrefs[0].end = inchar;
}
- match_state(t->to_state, inchar+1, incharsleft-1, m);
- /* yes, descent to all matching nodes, even if overrun, */
- /* since we can find a better one later */
- } else if (( t->range_start==EMPTY_START) && (t->range_end==EMPTY_END)) {
+ match_state(t->to_state, inchar,
+ inchar+1, incharsleft-1, m);
+ } else if (( t->range_start==EMPTY_START) &&
+ (t->range_end==EMPTY_END)) {
if ( m->empties++ > LOOP_LIMIT )
m->errorcode= YAZ_NFA_LOOP;
else
- match_state(t->to_state, inchar, incharsleft, m);
+ match_state(t->to_state, prevmatch,
+ inchar, incharsleft, m);
}
} while (t != s->lasttrans );
} else {
n->best_backrefs[i].end = 0;
}
- match_state(n->firststate, *inbuff, *incharsleft, &m);
+ match_state(n->firststate, *inbuff, *inbuff, *incharsleft, &m);
if (m.result) {
*incharsleft -= (m.longest-*inbuff);
*result = m.result;
return c;
}
+yaz_nfa_converter *yaz_nfa_create_range_converter (
+ yaz_nfa *n, int backref_no,
+ yaz_nfa_char from_char,
+ yaz_nfa_char to_char){
+ yaz_nfa_converter *c;
+ c=create_null_converter(n);
+ c->type=conv_range;
+ c->backref_no=backref_no;
+ c->char_diff=to_char - from_char;
+ return c;
+
+}
+
void yaz_nfa_append_converter (
yaz_nfa *n,
return 0;
if (i==1) /* no match in dfa */
return 1; /* should not happen */
- while (cp2>cp1) {
+ while (cp2>=cp1) {
if ((*outcharsleft)-- <= 0)
return 2;
**outbuff=*cp1++;
return 0;
}
+static int range_convert (
+ yaz_nfa *n,
+ yaz_nfa_converter *c,
+ yaz_nfa_char **outbuff,
+ size_t *outcharsleft){
+ yaz_nfa_char *cp1,*cp2;
+ int i;
+ i = yaz_nfa_get_backref(n,c->backref_no, &cp1, &cp2);
+ if (i == 2) /* no backref, produce no output, not ok */
+ return 1; /* should not happen */
+ if (i == 1) /* no match in dfa */
+ return 1; /* should not happen */
+ while (cp2 >= cp1) {
+ if ((*outcharsleft)-- <= 0)
+ return 2;
+ **outbuff=(*cp1++) + c->char_diff ;
+ (*outbuff)++;
+ }
+ return 0;
+}
+
int yaz_nfa_run_converters(
yaz_nfa *n,
yaz_nfa_char **outbuff,
size_t *outcharsleft){
int rc=0;
- // yaz_nfa_char *bufstart=*outbuff;
while (c && !rc) {
switch(c->type) {
case conv_string:
case conv_backref:
rc=backref_convert(n,c,outbuff,outcharsleft);
break;
+ case conv_range:
+ rc=range_convert(n,c,outbuff,outcharsleft);
+ break;
default:
rc=3; /* internal error */
}