/*
* Copyright (c) 1993-1994 by Xerox Corporation.  All rights reserved.
*
* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
* OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
*
* Permission is hereby granted to use or copy this program
* for any purpose,  provided the above notices are retained on all copies.
* Permission to modify the code and to distribute modified code is granted,
* provided the above notices are retained, and a notice that the code was
* modified is included with the above copyright notice.
*/

#ifndef EC_H
#define EC_H

# ifndef CORD_H
#  include "cord.h"
# endif

#ifdef __cplusplus
 extern "C" {
#endif

/* Extensible cords are strings that may be destructively appended to.  */
/* They allow fast construction of cords from characters that are       */
/* being read from a stream.                                            */
/*
* A client might look like:
*
*      {
*          CORD_ec x;
*          CORD result;
*          char c;
*          FILE *f;
*
*          ...
*          CORD_ec_init(x);
*          while (...) {
*              c = getc(f);
*              ...
*              CORD_ec_append(x, c);
*          }
*          result = CORD_balance(CORD_ec_to_cord(x));
*
* If a C string is desired as the final result, the call to CORD_balance
* may be replaced by a call to CORD_to_char_star.
*/

# ifndef CORD_BUFSZ
#   define CORD_BUFSZ 128
# endif

/* This structure represents the concatenation of ec_cord with  */
/* ec_buf[0 .. ec_bufptr-ec_buf-1].                             */
typedef struct CORD_ec_struct {
   CORD ec_cord;
   char * ec_bufptr;
   char ec_buf[CORD_BUFSZ+1];
} CORD_ec[1];

/* Flush the buffer part of the extended cord into ec_cord.     */
/* Note that this is almost the only real function, and it is   */
/* implemented in 6 lines in cordxtra.c                         */
void CORD_ec_flush_buf(CORD_ec x);

/* Convert an extensible cord to a cord. */
# define CORD_ec_to_cord(x) (CORD_ec_flush_buf(x), (x)[0].ec_cord)

/* Initialize an extensible cord. */
#define CORD_ec_init(x) \
               ((x)[0].ec_cord = 0, (void)((x)[0].ec_bufptr = (x)[0].ec_buf))

/* Append a character to an extensible cord.    */
#define CORD_ec_append(x, c) \
               ((void)((x)[0].ec_bufptr == (x)[0].ec_buf + CORD_BUFSZ \
                       ? (CORD_ec_flush_buf(x), 0) : 0), \
                (void)(*(x)[0].ec_bufptr++ = (c)))

/* Append a cord to an extensible cord.  Structure remains shared with  */
/* original.                                                            */
void CORD_ec_append_cord(CORD_ec x, CORD s);

#ifdef __cplusplus
 } /* extern "C" */
#endif

#endif /* EC_H */