Resending this page after Phil kindly showed me where to subscribe :)
sorry for posting "user questions", didn't find a user mailinglist.
Example:
char * pattern = "(abc.*deff)|(c.*x)";
char * data1 = " XX abc zz";
char * data2 = "";
char * data3 = " x";
Trying to PCRE_DFA_RESTART on data 2 and 3
yields:
|| pcre_dfa_exec data1 -12
|| ovector [0] = 4
|| ovector [1] = 11
[...]
|| pcre_dfa_exec data2 -1
|| ovector [0] = 4
|| ovector [1] = 11
[...]
|| pcre_dfa_exec data3 -1
|| ovector [0] = 4
|| ovector [1] = 11
Thus a partial match start at data1 pos "abc" is found as expected.
However the second alternative choice (c.*x) should finally match,
but does not. Is this a limitation of the implementation?
Eg adding the final x to data1 like this:
char * data1 = " XX abc zz x";
makes the code print:
|| ovector [0] = 4
|| ovector [1] = 13
and the char after x is position 13.
So the engine can cope with it.
Thus how to find out which pos/char (line) started to match the pattern?
I'd like to know whether its a good idea to suggest to Bram also adding
pcre support to the vim text editor - now that there will be 2 engines
already anyway.
full code I used for testing:
#include <stdio.h>
#include <string.h>
#include <pcre.h>
char * pattern = "(abc.*deff)|(c.*x)";
char * data1 = " XX abc zz";
char * data2 = "";
char * data3 = " x";
int main(int argc, char const *argv[])
{
pcre *re;
const char *error;
int erroffset;
int i;
// PCRE_NO_AUTO_CAPTURE
re = pcre_compile(
pattern, /* the pattern */
0, /* default options */
&error, /* for error message */
&erroffset, /* for error offset */
NULL); /* use default character tables */
if (re == NULL) {
printf("PCRE compilation failed at offset %d: %s\n", erroffset, error);
return 1;
}
#define OVECTOR_SIZE 20
int ovector[OVECTOR_SIZE];
for (i = 0; i < OVECTOR_SIZE; ++i) { ovector[i] = 11; }
#define WSPACE_SIZE 400
int wspace[WSPACE_SIZE];
int rc;
rc = pcre_dfa_exec(re,
0,
data1,
strlen(data1),
0, // start
PCRE_PARTIAL_HARD, // options
ovector, OVECTOR_SIZE,
wspace, WSPACE_SIZE
);
printf("pcre_dfa_exec data1 %d\n", rc);
for (i = 0; i < OVECTOR_SIZE; ++i) { printf("ovector [%d] = %d\n", i,
ovector[i]); }
rc = pcre_dfa_exec(re,
0,
data2,
strlen(data2),
0, // start
PCRE_DFA_RESTART, // options
ovector, OVECTOR_SIZE,
wspace, WSPACE_SIZE
);
printf("pcre_dfa_exec data2 %d\n", rc);
for (i = 0; i < OVECTOR_SIZE; ++i) { printf("ovector [%d] = %d\n", i,
ovector[i]); }
rc = pcre_dfa_exec(re,
0,
data3,
strlen(data3),
0, // start
PCRE_DFA_RESTART, // options
ovector, OVECTOR_SIZE,
wspace, WSPACE_SIZE
);
printf("pcre_dfa_exec data3 %d\n", rc);
for (i = 0; i < OVECTOR_SIZE; ++i) { printf("ovector [%d] = %d\n", i,
ovector[i]); }
printf("done\n");
return 0;
}
--
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