#include <glib.h>
#include <stdint.h>

/* The state of the parser.
 *
 * Members:
 *   input - the entire string being parsed
 *   index - current position in input
 *   length - size of input
 * THE FOLLOWING DESCRIBES HOW JSPARSE DOES IT. OUR MILEAGE MAY VARY.
 *   cache - a hash table describing the state of the parse, including partial parse_results. 
 *           It's actually a hash table of [parser_id, hash_table[index, parse_result]],
 *           where the parser id is incremented as the parse goes along (parsers that have
 *           already been applied once don't get a new parser_id ... but the global variable
 *           still increments? not sure why that is, need to debug some), and the locations
 *           at which it's been applied are memoized.
 *
 */
typedef struct {
  const uint8_t *input;
  size_t index;
  size_t length;
  GHashTable *cache; 
} parse_state;

typedef struct {
  const uint8_t *remaining;
  const uint8_t *matched;
  const GSequence *ast;
} parse_result;

typedef parse_result*(*parser)(parse_state*);

parser token(const uint8_t *s);
parser ch(const uint8_t c);
parser range(const uint8_t lower, const uint8_t upper);
parser whitespace(parser p);
//parser action(parser p, /* fptr to action on AST */);
parser join_action(parser p, const uint8_t *sep);
parser left_faction_action(parser p);
parser negate(parser p);
parser end_p();
parser nothing_p();
parser sequence(parser p_array[]);
parser choice(parser p_array[]);
parser butnot(parser p1, parser p2);
parser difference(parser p1, parser p2);
parser xor(parser p1, parser p2);
parser repeat0(parser p);
parser repeat1(parser p);
parser repeat_n(parser p, const size_t n);
parser optional(parser p);
parser expect(parser p);
parser chain(parser p1, parser p2, parser p3);
parser chainl(parser p1, parser p2);
parser list(parser p1, parser p2);
parser epsilon_p();
//parser semantic(/* fptr to nullary function? */);
parser and(parser p);
parser not(parser p);