C API
Installation
C API is a part of the official RL3 binary package. In order to install it, please consult the Installation Guide page.
Example usage
#include <stdio.h>
#include <stdlib.h>
#include <rl3.h>
/* check for engine execution errors */
void check_for_errors(struct RL3_Engine* engine)
{
if (rl3_engine_has_error(engine) != 0)
{
printf("Failed with error: %s\n", rl3_engine_get_error_str(engine));
exit(-1);
}
}
int main(void)
{
/* create engine and init it as "rl3" engine */
struct RL3_Engine* engine = rl3_engine_create(); check_for_errors(engine);
rl3_engine_init(engine, "rl3"); check_for_errors(engine);
/* parse and compile (link) simple annotation pattern */
const char* definition = rl3_make_simple_annotation_def(engine, "text", "(?i:{dawg continent})", "continent"); check_for_errors(engine);
rl3_engine_parse_inline(engine, definition, ".", 1); check_for_errors(engine);
rl3_engine_link(engine, 1); check_for_errors(engine);
/* create factsheet */
struct RL3_Factsheet* fs = rl3_factsheet_create(engine); check_for_errors(engine);
/* assert input text */
rl3_factsheet_assert_simple_fact(engine, fs, "text", "Antarctica is Earth's southernmost continent... Europe is the sixth largest continent in size.", 1.0);
check_for_errors(engine);
/* run engine - it should now annotate a continent names mentioned in our text */
rl3_engine_update(engine, fs); check_for_errors(engine);
/* iterate and print all "continent" annotations */
struct RL3_FactIterator* i = rl3_factsheet_get_fact_iterator(engine, fs, "continent"); check_for_errors(engine);
while (!rl3_factiterator_is_end(engine, i))
{
printf("%s\n", rl3_factiterator_get_value(engine, i)); check_for_errors(engine);
rl3_factiterator_next(engine, i); check_for_errors(engine);
}
/* release iterator */
rl3_factiterator_destroy(engine, i); check_for_errors(engine);
/* release factsheet */
rl3_factsheet_destroy(engine, fs); check_for_errors(engine);
/* release engine */
rl3_engine_destroy(engine);
return 0;
}
Output:
Antarctica Europe
General notes
- Use a
-lrl3compiler flag to link an RL3 library. - Almost every API call should be followed by an error check. In most cases errors can be interpreted as critical:
if (rl3_engine_has_error(engine) != 0)
{
printf("Failed with error: %s\n", rl3_engine_get_error_str(engine));
exit(-1);
}
- Engine instance must be created first and deleted last!
- All
const char*are zero terminated UTF-8 encoded strings. - Positional parameters always contain symbol coordinates, which may differ from byte coordinates in case of UTF-8 encoded unicode symbols.
- All
const char*return values that must be copied (strcpy) or printed immediately after retrieving. - In case of const pointers, ownership is NOT transferred.
rl3_fact_get_factsheetdoes NOT transfer ownership of a return value.- In multithreading environment RL3 resources should not be shared between threads.