summaryrefslogtreecommitdiffstats
path: root/src/include/access/sdir.h
blob: 8154adf3b822cb836786ac75af30292faaa76745 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
/*-------------------------------------------------------------------------
 *
 * sdir.h
 *	  POSTGRES scan direction definitions.
 *
 *
 * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
 * Portions Copyright (c) 1994, Regents of the University of California
 *
 * src/include/access/sdir.h
 *
 *-------------------------------------------------------------------------
 */
#ifndef SDIR_H
#define SDIR_H


/*
 * ScanDirection was an int8 for no apparent reason. I kept the original
 * values because I'm not sure if I'll break anything otherwise.  -ay 2/95
 */
typedef enum ScanDirection
{
	BackwardScanDirection = -1,
	NoMovementScanDirection = 0,
	ForwardScanDirection = 1
} ScanDirection;

/*
 * ScanDirectionIsValid
 *		True iff scan direction is valid.
 */
#define ScanDirectionIsValid(direction) \
	((bool) (BackwardScanDirection <= (direction) && \
			 (direction) <= ForwardScanDirection))

/*
 * ScanDirectionIsBackward
 *		True iff scan direction is backward.
 */
#define ScanDirectionIsBackward(direction) \
	((bool) ((direction) == BackwardScanDirection))

/*
 * ScanDirectionIsNoMovement
 *		True iff scan direction indicates no movement.
 */
#define ScanDirectionIsNoMovement(direction) \
	((bool) ((direction) == NoMovementScanDirection))

/*
 * ScanDirectionIsForward
 *		True iff scan direction is forward.
 */
#define ScanDirectionIsForward(direction) \
	((bool) ((direction) == ForwardScanDirection))

#endif							/* SDIR_H */