Annotation of OpenXM_contrib/gc/include/private/cord_pos.h, Revision 1.1.1.1
1.1 maekawa 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: /* Boehm, May 19, 1994 2:23 pm PDT */
14: # ifndef CORD_POSITION_H
15:
16: /* The representation of CORD_position. This is private to the */
17: /* implementation, but the size is known to clients. Also */
18: /* the implementation of some exported macros relies on it. */
19: /* Don't use anything defined here and not in cord.h. */
20:
21: # define MAX_DEPTH 48
22: /* The maximum depth of a balanced cord + 1. */
23: /* We don't let cords get deeper than MAX_DEPTH. */
24:
25: struct CORD_pe {
26: CORD pe_cord;
27: size_t pe_start_pos;
28: };
29:
30: /* A structure describing an entry on the path from the root */
31: /* to current position. */
32: typedef struct CORD_Pos {
33: size_t cur_pos;
34: int path_len;
35: # define CORD_POS_INVALID (0x55555555)
36: /* path_len == INVALID <==> position invalid */
37: const char *cur_leaf; /* Current leaf, if it is a string. */
38: /* If the current leaf is a function, */
39: /* then this may point to function_buf */
40: /* containing the next few characters. */
41: /* Always points to a valid string */
42: /* containing the current character */
43: /* unless cur_end is 0. */
44: size_t cur_start; /* Start position of cur_leaf */
45: size_t cur_end; /* Ending position of cur_leaf */
46: /* 0 if cur_leaf is invalid. */
47: struct CORD_pe path[MAX_DEPTH + 1];
48: /* path[path_len] is the leaf corresponding to cur_pos */
49: /* path[0].pe_cord is the cord we point to. */
50: # define FUNCTION_BUF_SZ 8
51: char function_buf[FUNCTION_BUF_SZ]; /* Space for next few chars */
52: /* from function node. */
53: } CORD_pos[1];
54:
55: /* Extract the cord from a position: */
56: CORD CORD_pos_to_cord(CORD_pos p);
57:
58: /* Extract the current index from a position: */
59: size_t CORD_pos_to_index(CORD_pos p);
60:
61: /* Fetch the character located at the given position: */
62: char CORD_pos_fetch(CORD_pos p);
63:
64: /* Initialize the position to refer to the give cord and index. */
65: /* Note that this is the most expensive function on positions: */
66: void CORD_set_pos(CORD_pos p, CORD x, size_t i);
67:
68: /* Advance the position to the next character. */
69: /* P must be initialized and valid. */
70: /* Invalidates p if past end: */
71: void CORD_next(CORD_pos p);
72:
73: /* Move the position to the preceding character. */
74: /* P must be initialized and valid. */
75: /* Invalidates p if past beginning: */
76: void CORD_prev(CORD_pos p);
77:
78: /* Is the position valid, i.e. inside the cord? */
79: int CORD_pos_valid(CORD_pos p);
80:
81: char CORD__pos_fetch(CORD_pos);
82: void CORD__next(CORD_pos);
83: void CORD__prev(CORD_pos);
84:
85: #define CORD_pos_fetch(p) \
86: (((p)[0].cur_end != 0)? \
87: (p)[0].cur_leaf[(p)[0].cur_pos - (p)[0].cur_start] \
88: : CORD__pos_fetch(p))
89:
90: #define CORD_next(p) \
91: (((p)[0].cur_pos + 1 < (p)[0].cur_end)? \
92: (p)[0].cur_pos++ \
93: : (CORD__next(p), 0))
94:
95: #define CORD_prev(p) \
96: (((p)[0].cur_end != 0 && (p)[0].cur_pos > (p)[0].cur_start)? \
97: (p)[0].cur_pos-- \
98: : (CORD__prev(p), 0))
99:
100: #define CORD_pos_to_index(p) ((p)[0].cur_pos)
101:
102: #define CORD_pos_to_cord(p) ((p)[0].path[0].pe_cord)
103:
104: #define CORD_pos_valid(p) ((p)[0].path_len != CORD_POS_INVALID)
105:
106: /* Some grubby stuff for performance-critical friends: */
107: #define CORD_pos_chars_left(p) ((long)((p)[0].cur_end) - (long)((p)[0].cur_pos))
108: /* Number of characters in cache. <= 0 ==> none */
109:
110: #define CORD_pos_advance(p,n) ((p)[0].cur_pos += (n) - 1, CORD_next(p))
111: /* Advance position by n characters */
112: /* 0 < n < CORD_pos_chars_left(p) */
113:
114: #define CORD_pos_cur_char_addr(p) \
115: (p)[0].cur_leaf + ((p)[0].cur_pos - (p)[0].cur_start)
116: /* address of current character in cache. */
117:
118: #endif
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