text: /*-------------------------------------------------------------------------
   *
   * valid.h
   *	  POSTGRES tuple qualification validity definitions.
   *
   *
   * Portions Copyright (c) 1996-2010, PostgreSQL Global Development Group
   * Portions Copyright (c) 1994, Regents of the University of California
   *
   * $PostgreSQL: pgsql/src/include/access/valid.h,v 1.42 2010/01/02 16:58:00 momjian Exp $
   *
   *-------------------------------------------------------------------------
   */
  #ifndef VALID_H
  #define VALID_H
  
  /*
   *		HeapKeyTest
   *
   *		Test a heap tuple to see if it satisfies a scan key.
   */
  #define HeapKeyTest(tuple, \
  					tupdesc, \
  					nkeys, \
  					keys, \
  					result) \
  do \
  { \
  	/* Use underscores to protect the variables passed in as parameters */ \
  	int			__cur_nkeys = (nkeys); \
  	ScanKey		__cur_keys = (keys); \
   \
  	(result) = true; /* may change */ \
  	for (; __cur_nkeys--; __cur_keys++) \
  	{ \
  		Datum	__atp; \
  		bool	__isnull; \
  		Datum	__test; \
   \
  		if (__cur_keys->sk_flags & SK_ISNULL) \
  		{ \
  			(result) = false; \
  			break; \
  		} \
   \
  		__atp = heap_getattr((tuple), \
  							 __cur_keys->sk_attno, \
  							 (tupdesc), \
  							 &__isnull); \
   \
  		if (__isnull) \
  		{ \
  			(result) = false; \
  			break; \
  		} \
   \
  		__test = FunctionCall2(&__cur_keys->sk_func, \
  							   __atp, __cur_keys->sk_argument); \
   \
  		if (!DatumGetBool(__test)) \
  		{ \
  			(result) = false; \
  			break; \
  		} \
  	} \
  } while (0)
  
  #endif   /* VALID_H */
  