Postgres95 1.01 Distribution - Virgin Sources

src/backend/nodes/nodeFuncs.c

@@ -0,0 +1,116 @@
+/*-------------------------------------------------------------------------
+ *
+ * nodeFuncs.c--
+ *    All node routines more complicated than simple access/modification
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *    $Header: /cvsroot/pgsql/src/backend/nodes/nodeFuncs.c,v 1.1.1.1 1996/07/09 06:21:32 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "c.h"
+
+#include "nodes/primnodes.h"
+#include "nodes/plannodes.h"
+#include "nodes/pg_list.h"
+#include "nodes/relation.h"
+#include "nodes/nodeFuncs.h"
+#include "utils/lsyscache.h"
+
+/*    
+ * single_node -
+ *    Returns t if node corresponds to a single-noded expression
+ */
+bool
+single_node(Node *node)
+{
+    if(IsA(node,Ident) || IsA(node,Const) || IsA(node,Var) || IsA(node,Param)) 
+	return(true);
+    else
+	return(false);
+}
+
+/*****************************************************************************
+ *    	VAR nodes
+ *****************************************************************************/
+
+/*    
+ *    	var_is_outer
+ *    	var_is_inner
+ *    	var_is_mat
+ *    	var_is_rel
+ *    
+ *    	Returns t iff the var node corresponds to (respectively):
+ *    	the outer relation in a join
+ *    	the inner relation of a join
+ *    	a materialized relation
+ *    	a base relation (i.e., not an attribute reference, a variable from
+ *    		some lower join level, or a sort result)
+ *      var node is an array reference
+ *    
+ */
+bool
+var_is_outer (Var *var)
+{
+    return((bool)(var->varno == OUTER));
+}
+
+bool
+var_is_inner (Var *var)
+{
+    return ( (bool) (var->varno == INNER));
+}
+
+bool
+var_is_rel (Var *var)
+{
+    return (bool)
+	! (var_is_inner (var) ||  var_is_outer (var));
+}
+
+/*****************************************************************************
+ *    	OPER nodes
+ *****************************************************************************/
+
+/*    
+ * replace_opid -
+ *    
+ *    	Given a oper node, resets the opfid field with the
+ *    	procedure OID (regproc id).
+ *    
+ *    	Returns the modified oper node.
+ *    
+ */
+Oper *
+replace_opid (Oper *oper)
+{
+    oper->opid = get_opcode(oper->opno);
+    oper->op_fcache = NULL;
+    return(oper);
+}
+
+/*****************************************************************************
+ *    	constant (CONST, PARAM) nodes
+ *****************************************************************************/
+
+/*    
+ * non_null -
+ *    	Returns t if the node is a non-null constant, e.g., if the node has a
+ *    	valid `constvalue' field.
+ *    
+ */
+bool
+non_null (Expr *c)
+{
+    
+    if ( IsA(c,Const) && ! ((Const*)c)->constisnull )
+	return(true);
+    else
+	return(false);
+}
+
+
+