| 1 | /* |
| 2 | * Copyright (c) 1993-1994 by Xerox Corporation. All rights reserved. |
| 3 | * |
| 4 | * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED |
| 5 | * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. |
| 6 | * |
| 7 | * Permission is hereby granted to use or copy this program |
| 8 | * for any purpose, provided the above notices are retained on all copies. |
| 9 | * Permission to modify the code and to distribute modified code is granted, |
| 10 | * provided the above notices are retained, and a notice that the code was |
| 11 | * modified is included with the above copyright notice. |
| 12 | */ |
| 13 | |
| 14 | #ifndef EC_H |
| 15 | #define EC_H |
| 16 | |
| 17 | #ifndef CORD_H |
| 18 | # include "cord.h" |
| 19 | #endif |
| 20 | |
| 21 | #ifdef __cplusplus |
| 22 | extern "C" { |
| 23 | #endif |
| 24 | |
| 25 | /* |
| 26 | * Extensible cords are strings that may be destructively appended to. |
| 27 | * They allow fast construction of cords from characters that are being |
| 28 | * read from a stream. |
| 29 | * |
| 30 | * A client might look like: |
| 31 | * ``` |
| 32 | * CORD_ec x; |
| 33 | * CORD result; |
| 34 | * char c; |
| 35 | * FILE *f; |
| 36 | * |
| 37 | * CORD_ec_init(x); |
| 38 | * while (...) { |
| 39 | * c = getc(f); |
| 40 | * ... |
| 41 | * CORD_ec_append(x, c); |
| 42 | * } |
| 43 | * result = CORD_balance(CORD_ec_to_cord(x)); |
| 44 | * ``` |
| 45 | * |
| 46 | * If a C string is desired as the final result, the call to `CORD_balance` |
| 47 | * may be replaced by a call to `CORD_to_char_star`. |
| 48 | */ |
| 49 | |
| 50 | #ifndef CORD_BUFSZ |
| 51 | # define CORD_BUFSZ 128 |
| 52 | #endif |
| 53 | |
| 54 | /** |
| 55 | * This structure represents the concatenation of `ec_cord` with |
| 56 | * `ec_buf[0 .. ec_bufptr - ec_buf - 1]`. |
| 57 | */ |
| 58 | typedef struct CORD_ec_struct { |
| 59 | CORD ec_cord; |
| 60 | char *ec_bufptr; |
| 61 | char ec_buf[CORD_BUFSZ + 1]; |
| 62 | } CORD_ec[1]; |
| 63 | |
| 64 | /** Flush the buffer part of the extended cord into extensible cord. */ |
| 65 | CORD_API void CORD_ec_flush_buf(CORD_ec); |
| 66 | |
| 67 | /** Convert an extensible cord to a cord. */ |
| 68 | #define CORD_ec_to_cord(x) (CORD_ec_flush_buf(x), (x)[0].ec_cord) |
| 69 | |
| 70 | /** Initialize an extensible cord. */ |
| 71 | #define CORD_ec_init(x) \ |
| 72 | ((x)[0].ec_cord = 0, (void)((x)[0].ec_bufptr = (x)[0].ec_buf)) |
| 73 | |
| 74 | /** Append a character to an extensible cord. */ |
| 75 | #define CORD_ec_append(x, c) \ |
| 76 | ((void)((x)[0].ec_bufptr == (x)[0].ec_buf + CORD_BUFSZ \ |
| 77 | ? (CORD_ec_flush_buf(x), 0) \ |
| 78 | : 0), \ |
| 79 | (void)(*(x)[0].ec_bufptr++ = (c))) |
| 80 | |
| 81 | /** |
| 82 | * Append a cord to an extensible cord. Structure remains shared with |
| 83 | * the original. |
| 84 | */ |
| 85 | CORD_API void CORD_ec_append_cord(CORD_ec, CORD); |
| 86 | |
| 87 | #ifdef __cplusplus |
| 88 | } /* extern "C" */ |
| 89 | #endif |
| 90 | |
| 91 | #endif /* EC_H */ |
| 92 | |