/* This source file is part of the LynxLib miscellaneous library by
Robert Fischer, and is Copyright 1990 by Robert Fischer.  It costs no
money, and you may not make money off of it, but you may redistribute
it.  It comes with ABSOLUTELY NO WARRANTY.  See the file LYNXLIB.DOC
for more details.
To contact the author:
    Robert Fischer \\80 Killdeer Rd \\Hamden, CT   06517   USA
    (203) 288-9599     fischer-robert@cs.yale.edu                 */

/* By Robert Fischer, August 1988 */

/*
This is a header file for virtual files A virtual file is a file
stream that could come from anywhere -- a FILE, memory, etc.  The user
program must implement the different drivers for different kinds of
VFILEs.  mfile.c contains the driver for memory files, and ffile.c
contains the driver for C files gotten with fopen, fclose, etc.  */

#ifndef STDDEF_H
#include <stddef.h>
#endif

typedef struct {    /* This is a general file from any device or place */
    func  *do_putc;     /* Routine to call to put char, as putc(char, p) */
    ifunc *do_getc;
    ifunc *do_eof;
    lfunc *curpos;      /* Finds the current file pointer position */
    func  *do_close;    /* Routine to close the file with */
    char *p;        /* Pointer to file info for putc, getc, eof */
} VFILE;

#define vputc(c, v) (*((v)->do_putc))(c, (v)->p)
#define vgetc(v)    ((int)(*((v)->do_getc))((v)->p))
#define veof(v)     (*((v)->do_eof))((v)->p)
#define vcurpos(v)  (*((v)->curpos))((v)->p)
#define vclose(v)   {(*((v)->do_close))((v)->p); free(v);}

/* Here's a list of the different supported open commands */
extern VFILE *open_mfile();     /* memfile */
extern VFILE *open_ffile();     /* ffile */
extern VFILE *open_cofile();    /* cofiles, streams by coroutines */

/* This is a structure of two file pointers, for routines that like to */
/* take an input and output file argument */
typedef struct {
    VFILE *in;
    VFILE *out;
} VFILE_REC;