init

db_include/access/sdir.h

@@ -0,0 +1,58 @@
+/*-------------------------------------------------------------------------
+ *
+ * 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 */