#ifndef INPUT_H
#define INPUT_H

#include "grammar.h"

/* The class of a general reader, which can read a grammar, either
   from a file, or elsewhere, such as from an Emacs buffer, the
   standard input, or even from some other places.

   The only expectation, or requirement, of such a reader is to
   provide a function with a variable number and type of arguments
   which returns a grammar.  Then the package provides a function to
   properly read a grammar, according to the specifications of the
   reader. */

typedef Grammar *(*reader_func_t)(List *args);

typedef struct Reader_s Reader;

/* contructor */

/* Build a reader and assign to *reader.  It is expected to be
   allocated before this function. */
void build_reader(Reader *reader, reader_func_t func, List *args);

/* destructor */

/* Does not free READER.

   FLAG is passed to destroy_list, which see. */
void destroy_reader(Reader *reader, int flag);


#endif