| 1 | # ifndef EC_H
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| 2 | # define EC_H
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| 3 |
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| 4 | # ifndef CORD_H
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| 5 | # include "cord.h"
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| 6 | # endif
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| 7 |
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| 8 | /* Extensible cords are strings that may be destructively appended to. */
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| 9 | /* They allow fast construction of cords from characters that are */
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| 10 | /* being read from a stream. */
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| 11 | /*
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| 12 | * A client might look like:
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| 13 | *
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| 14 | * {
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| 15 | * CORD_ec x;
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| 16 | * CORD result;
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| 17 | * char c;
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| 18 | * FILE *f;
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| 19 | *
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| 20 | * ...
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| 21 | * CORD_ec_init(x);
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| 22 | * while(...) {
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| 23 | * c = getc(f);
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| 24 | * ...
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| 25 | * CORD_ec_append(x, c);
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| 26 | * }
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| 27 | * result = CORD_balance(CORD_ec_to_cord(x));
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| 28 | *
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| 29 | * If a C string is desired as the final result, the call to CORD_balance
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| 30 | * may be replaced by a call to CORD_to_char_star.
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| 31 | */
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| 32 |
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| 33 | # ifndef CORD_BUFSZ
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| 34 | # define CORD_BUFSZ 128
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| 35 | # endif
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| 36 |
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| 37 | typedef struct CORD_ec_struct {
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| 38 | CORD ec_cord;
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| 39 | char * ec_bufptr;
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| 40 | char ec_buf[CORD_BUFSZ+1];
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| 41 | } CORD_ec[1];
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| 42 |
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| 43 | /* This structure represents the concatenation of ec_cord with */
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| 44 | /* ec_buf[0 ... (ec_bufptr-ec_buf-1)] */
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| 45 |
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| 46 | /* Flush the buffer part of the extended chord into ec_cord. */
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| 47 | /* Note that this is almost the only real function, and it is */
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| 48 | /* implemented in 6 lines in cordxtra.c */
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| 49 | void CORD_ec_flush_buf(CORD_ec x);
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| 50 |
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| 51 | /* Convert an extensible cord to a cord. */
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| 52 | # define CORD_ec_to_cord(x) (CORD_ec_flush_buf(x), (x)[0].ec_cord)
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| 53 |
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| 54 | /* Initialize an extensible cord. */
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| 55 | # define CORD_ec_init(x) ((x)[0].ec_cord = 0, (x)[0].ec_bufptr = (x)[0].ec_buf)
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| 56 |
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| 57 | /* Append a character to an extensible cord. */
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| 58 | # define CORD_ec_append(x, c) \
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| 59 | { \
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| 60 | if ((x)[0].ec_bufptr == (x)[0].ec_buf + CORD_BUFSZ) { \
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| 61 | CORD_ec_flush_buf(x); \
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| 62 | } \
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| 63 | *((x)[0].ec_bufptr)++ = (c); \
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| 64 | }
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| 65 |
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| 66 | /* Append a cord to an extensible cord. Structure remains shared with */
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| 67 | /* original. */
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| 68 | void CORD_ec_append_cord(CORD_ec x, CORD s);
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| 69 |
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| 70 | # endif /* EC_H */
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