Get rid of last few vestiges of parsetree dependency on grammar token

codes, per discussion from last March.  parse.h should now be included
*only* by gram.y, scan.l, keywords.c, parser.c.  This prevents surprising
misbehavior after seemingly-trivial grammar adjustments.

src/backend/nodes/copyfuncs.c

@@ -15,7 +15,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.242 2003/02/09 06:56:27 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/copyfuncs.c,v 1.243 2003/02/10 04:44:44 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1198,7 +1198,7 @@ _copyAExpr(A_Expr *from)
 {
 	A_Expr	   *newnode = makeNode(A_Expr);
 
-	COPY_SCALAR_FIELD(oper);
+	COPY_SCALAR_FIELD(kind);
 	COPY_NODE_FIELD(name);
 	COPY_NODE_FIELD(lexpr);
 	COPY_NODE_FIELD(rexpr);
@@ -1669,7 +1669,7 @@ _copyDefineStmt(DefineStmt *from)
 {
 	DefineStmt *newnode = makeNode(DefineStmt);
 
-	COPY_SCALAR_FIELD(defType);
+	COPY_SCALAR_FIELD(kind);
 	COPY_NODE_FIELD(defnames);
 	COPY_NODE_FIELD(definition);
 
@@ -1869,7 +1869,7 @@ _copyTransactionStmt(TransactionStmt *from)
 {
 	TransactionStmt *newnode = makeNode(TransactionStmt);
 
-	COPY_SCALAR_FIELD(command);
+	COPY_SCALAR_FIELD(kind);
 	COPY_NODE_FIELD(options);
 
 	return newnode;
@@ -2215,7 +2215,7 @@ _copyReindexStmt(ReindexStmt *from)
 {
 	ReindexStmt *newnode = makeNode(ReindexStmt);
 
-	COPY_SCALAR_FIELD(reindexType);
+	COPY_SCALAR_FIELD(kind);
 	COPY_NODE_FIELD(relation);
 	COPY_STRING_FIELD(name);
 	COPY_SCALAR_FIELD(force);

src/backend/nodes/equalfuncs.c

@@ -18,7 +18,7 @@
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.185 2003/02/09 06:56:27 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/equalfuncs.c,v 1.186 2003/02/10 04:44:45 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -730,7 +730,7 @@ _equalCreateStmt(CreateStmt *a, CreateStmt *b)
 static bool
 _equalDefineStmt(DefineStmt *a, DefineStmt *b)
 {
-	COMPARE_SCALAR_FIELD(defType);
+	COMPARE_SCALAR_FIELD(kind);
 	COMPARE_NODE_FIELD(defnames);
 	COMPARE_NODE_FIELD(definition);
 
@@ -898,7 +898,7 @@ _equalUnlistenStmt(UnlistenStmt *a, UnlistenStmt *b)
 static bool
 _equalTransactionStmt(TransactionStmt *a, TransactionStmt *b)
 {
-	COMPARE_SCALAR_FIELD(command);
+	COMPARE_SCALAR_FIELD(kind);
 	COMPARE_NODE_FIELD(options);
 
 	return true;
@@ -1187,7 +1187,7 @@ _equalDropGroupStmt(DropGroupStmt *a, DropGroupStmt *b)
 static bool
 _equalReindexStmt(ReindexStmt *a, ReindexStmt *b)
 {
-	COMPARE_SCALAR_FIELD(reindexType);
+	COMPARE_SCALAR_FIELD(kind);
 	COMPARE_NODE_FIELD(relation);
 	COMPARE_STRING_FIELD(name);
 	COMPARE_SCALAR_FIELD(force);
@@ -1276,7 +1276,7 @@ _equalDeallocateStmt(DeallocateStmt *a, DeallocateStmt *b)
 static bool
 _equalAExpr(A_Expr *a, A_Expr *b)
 {
-	COMPARE_SCALAR_FIELD(oper);
+	COMPARE_SCALAR_FIELD(kind);
 	COMPARE_NODE_FIELD(name);
 	COMPARE_NODE_FIELD(lexpr);
 	COMPARE_NODE_FIELD(rexpr);

src/backend/nodes/makefuncs.c

@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/makefuncs.c,v 1.37 2002/12/12 15:49:28 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/makefuncs.c,v 1.38 2003/02/10 04:44:45 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -24,11 +24,11 @@
  *		makes an A_Expr node
  */
 A_Expr *
-makeA_Expr(int oper, List *name, Node *lexpr, Node *rexpr)
+makeA_Expr(A_Expr_Kind kind, List *name, Node *lexpr, Node *rexpr)
 {
 	A_Expr	   *a = makeNode(A_Expr);
 
-	a->oper = oper;
+	a->kind = kind;
 	a->name = name;
 	a->lexpr = lexpr;
 	a->rexpr = rexpr;
@@ -40,12 +40,12 @@ makeA_Expr(int oper, List *name, Node *lexpr, Node *rexpr)
  *		As above, given a simple (unqualified) operator name
  */
 A_Expr *
-makeSimpleA_Expr(int oper, const char *name,
+makeSimpleA_Expr(A_Expr_Kind kind, const char *name,
 				 Node *lexpr, Node *rexpr)
 {
 	A_Expr	   *a = makeNode(A_Expr);
 
-	a->oper = oper;
+	a->kind = kind;
 	a->name = makeList1(makeString((char *) name));
 	a->lexpr = lexpr;
 	a->rexpr = rexpr;

src/backend/nodes/outfuncs.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/nodes/outfuncs.c,v 1.198 2003/02/09 06:56:27 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/nodes/outfuncs.c,v 1.199 2003/02/10 04:44:45 tgl Exp $
  *
  * NOTES
  *	  Every node type that can appear in stored rules' parsetrees *must*
@@ -27,7 +27,6 @@
 #include "nodes/parsenodes.h"
 #include "nodes/plannodes.h"
 #include "nodes/relation.h"
-#include "parser/parse.h"
 #include "utils/datum.h"
 
 
@@ -1259,19 +1258,27 @@ _outAExpr(StringInfo str, A_Expr *node)
 {
 	WRITE_NODE_TYPE("AEXPR");
 
-	switch (node->oper)
+	switch (node->kind)
 	{
-		case AND:
+		case AEXPR_OP:
+			appendStringInfo(str, " ");
+			WRITE_NODE_FIELD(name);
+			break;
+		case AEXPR_AND:
 			appendStringInfo(str, " AND");
 			break;
-		case OR:
+		case AEXPR_OR:
 			appendStringInfo(str, " OR");
 			break;
-		case NOT:
+		case AEXPR_NOT:
 			appendStringInfo(str, " NOT");
 			break;
-		case OP:
-			appendStringInfo(str, " ");
+		case AEXPR_DISTINCT:
+			appendStringInfo(str, " DISTINCT ");
+			WRITE_NODE_FIELD(name);
+			break;
+		case AEXPR_OF:
+			appendStringInfo(str, " OF ");
 			WRITE_NODE_FIELD(name);
 			break;
 		default:

src/backend/parser/Makefile

@@ -2,7 +2,7 @@
 #
 # Makefile for parser
 #
-# $Header: /cvsroot/pgsql/src/backend/parser/Makefile,v 1.39 2003/01/31 20:58:00 tgl Exp $
+# $Header: /cvsroot/pgsql/src/backend/parser/Makefile,v 1.40 2003/02/10 04:44:45 tgl Exp $
 #
 #-------------------------------------------------------------------------
 
@@ -64,7 +64,7 @@ endif
 
 # Force these dependencies to be known even without dependency info built:
 
-keywords.o parse_clause.o parse_expr.o parser.o gram.o: $(srcdir)/parse.h
+gram.o keywords.o parser.o: $(srcdir)/parse.h
 
 
 # gram.c, parse.h, and scan.c are in the distribution tarball, so they

src/backend/parser/keywords.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/keywords.c,v 1.133 2003/02/03 14:04:24 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/keywords.c,v 1.134 2003/02/10 04:44:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -30,7 +30,7 @@
  */
 static const ScanKeyword ScanKeywords[] = {
 	/* name, value */
-	{"abort", ABORT_TRANS},
+	{"abort", ABORT_P},
 	{"absolute", ABSOLUTE},
 	{"access", ACCESS},
 	{"action", ACTION},
@@ -51,7 +51,7 @@ static const ScanKeyword ScanKeywords[] = {
 	{"authorization", AUTHORIZATION},
 	{"backward", BACKWARD},
 	{"before", BEFORE},
-	{"begin", BEGIN_TRANS},
+	{"begin", BEGIN_P},
 	{"between", BETWEEN},
 	{"bigint", BIGINT},
 	{"binary", BINARY},
@@ -117,7 +117,7 @@ static const ScanKeyword ScanKeywords[] = {
 	{"else", ELSE},
 	{"encoding", ENCODING},
 	{"encrypted", ENCRYPTED},
-	{"end", END_TRANS},
+	{"end", END_P},
 	{"escape", ESCAPE},
 	{"except", EXCEPT},
 	{"exclusive", EXCLUSIVE},
@@ -137,7 +137,6 @@ static const ScanKeyword ScanKeywords[] = {
 	{"from", FROM},
 	{"full", FULL},
 	{"function", FUNCTION},
-	{"get", GET},
 	{"global", GLOBAL},
 	{"grant", GRANT},
 	{"group", GROUP_P},

src/backend/parser/parse_clause.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.105 2003/02/09 06:56:28 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_clause.c,v 1.106 2003/02/10 04:44:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -22,7 +22,6 @@
 #include "optimizer/tlist.h"
 #include "optimizer/var.h"
 #include "parser/analyze.h"
-#include "parser/parse.h"
 #include "parser/parsetree.h"
 #include "parser/parse_clause.h"
 #include "parser/parse_coerce.h"
@@ -263,7 +262,7 @@ transformJoinUsingClause(ParseState *pstate, List *leftVars, List *rightVars)
 		Node	   *rvar = (Node *) lfirst(rvars);
 		A_Expr	   *e;
 
-		e = makeSimpleA_Expr(OP, "=", copyObject(lvar), copyObject(rvar));
+		e = makeSimpleA_Expr(AEXPR_OP, "=", copyObject(lvar), copyObject(rvar));
 
 		if (result == NULL)
 			result = (Node *) e;
@@ -271,7 +270,7 @@ transformJoinUsingClause(ParseState *pstate, List *leftVars, List *rightVars)
 		{
 			A_Expr	   *a;
 
-			a = makeA_Expr(AND, NIL, result, (Node *) e);
+			a = makeA_Expr(AEXPR_AND, NIL, result, (Node *) e);
 			result = (Node *) a;
 		}
 

src/backend/parser/parse_expr.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_expr.c,v 1.143 2003/02/09 06:56:28 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/parser/parse_expr.c,v 1.144 2003/02/10 04:44:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -23,7 +23,6 @@
 #include "nodes/plannodes.h"
 #include "parser/analyze.h"
 #include "parser/gramparse.h"
-#include "parser/parse.h"
 #include "parser/parse_coerce.h"
 #include "parser/parse_expr.h"
 #include "parser/parse_func.h"
@@ -178,9 +177,9 @@ transformExpr(ParseState *pstate, Node *expr)
 			{
 				A_Expr	   *a = (A_Expr *) expr;
 
-				switch (a->oper)
+				switch (a->kind)
 				{
-					case OP:
+					case AEXPR_OP:
 						{
 							/*
 							 * Special-case "foo = NULL" and "NULL = foo"
@@ -219,7 +218,7 @@ transformExpr(ParseState *pstate, Node *expr)
 							}
 						}
 						break;
-					case AND:
+					case AEXPR_AND:
 						{
 							Node	   *lexpr = transformExpr(pstate,
 															  a->lexpr);
@@ -234,7 +233,7 @@ transformExpr(ParseState *pstate, Node *expr)
 																	 rexpr));
 						}
 						break;
-					case OR:
+					case AEXPR_OR:
 						{
 							Node	   *lexpr = transformExpr(pstate,
 															  a->lexpr);
@@ -249,7 +248,7 @@ transformExpr(ParseState *pstate, Node *expr)
 																	 rexpr));
 						}
 						break;
-					case NOT:
+					case AEXPR_NOT:
 						{
 							Node	   *rexpr = transformExpr(pstate,
 															  a->rexpr);
@@ -260,7 +259,7 @@ transformExpr(ParseState *pstate, Node *expr)
 														   makeList1(rexpr));
 						}
 						break;
-					case DISTINCT:
+					case AEXPR_DISTINCT:
 						{
 							Node	   *lexpr = transformExpr(pstate,
 															  a->lexpr);
@@ -278,18 +277,17 @@ transformExpr(ParseState *pstate, Node *expr)
 							NodeSetTag(result, T_DistinctExpr);
 						}
 						break;
-					case OF:
+					case AEXPR_OF:
 						{
+							/*
+							 * Checking an expression for match to type.
+							 * Will result in a boolean constant node.
+							 */
 							List	   *telem;
 							A_Const    *n;
 							Oid			ltype,
 										rtype;
 							bool		matched = FALSE;
-
-							/*
-							 * Checking an expression for match to type.
-							 * Will result in a boolean constant node.
-							 */
 							Node	   *lexpr = transformExpr(pstate,
 															  a->lexpr);
 
@@ -530,7 +528,7 @@ transformExpr(ParseState *pstate, Node *expr)
 					if (c->arg != NULL)
 					{
 						/* shorthand form was specified, so expand... */
-						warg = (Node *) makeSimpleA_Expr(OP, "=",
+						warg = (Node *) makeSimpleA_Expr(AEXPR_OP, "=",
 														 (Node *) c->arg,
 														 warg);
 					}

src/backend/tcop/postgres.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.314 2003/01/01 21:57:05 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.315 2003/02/10 04:44:46 tgl Exp $
  *
  * NOTES
  *	  this is the "main" module of the postgres backend and
@@ -44,7 +44,6 @@
 #include "optimizer/cost.h"
 #include "optimizer/planner.h"
 #include "parser/analyze.h"
-#include "parser/parse.h"
 #include "parser/parser.h"
 #include "rewrite/rewriteHandler.h"
 #include "storage/ipc.h"
@@ -666,7 +665,8 @@ pg_exec_query_string(StringInfo query_string,	/* string to execute */
 			{
 				TransactionStmt *stmt = (TransactionStmt *) parsetree;
 
-				if (stmt->command == COMMIT || stmt->command == ROLLBACK)
+				if (stmt->kind == TRANS_STMT_COMMIT ||
+					stmt->kind == TRANS_STMT_ROLLBACK)
 					allowit = true;
 			}
 
@@ -1781,7 +1781,7 @@ PostgresMain(int argc, char *argv[], const char *username)
 	if (!IsUnderPostmaster)
 	{
 		puts("\nPOSTGRES backend interactive interface ");
-		puts("$Revision: 1.314 $ $Date: 2003/01/01 21:57:05 $\n");
+		puts("$Revision: 1.315 $ $Date: 2003/02/10 04:44:46 $\n");
 	}
 
 	/*
@@ -2212,21 +2212,21 @@ CreateCommandTag(Node *parsetree)
 			{
 				TransactionStmt *stmt = (TransactionStmt *) parsetree;
 
-				switch (stmt->command)
+				switch (stmt->kind)
 				{
-					case BEGIN_TRANS:
+					case TRANS_STMT_BEGIN:
 						tag = "BEGIN";
 						break;
 
-					case START:
+					case TRANS_STMT_START:
 						tag = "START TRANSACTION";
 						break;
 
-					case COMMIT:
+					case TRANS_STMT_COMMIT:
 						tag = "COMMIT";
 						break;
 
-					case ROLLBACK:
+					case TRANS_STMT_ROLLBACK:
 						tag = "ROLLBACK";
 						break;
 
@@ -2329,15 +2329,15 @@ CreateCommandTag(Node *parsetree)
 			break;
 
 		case T_DefineStmt:
-			switch (((DefineStmt *) parsetree)->defType)
+			switch (((DefineStmt *) parsetree)->kind)
 			{
-				case AGGREGATE:
+				case DEFINE_STMT_AGGREGATE:
 					tag = "CREATE AGGREGATE";
 					break;
-				case OPERATOR:
+				case DEFINE_STMT_OPERATOR:
 					tag = "CREATE OPERATOR";
 					break;
-				case TYPE_P:
+				case DEFINE_STMT_TYPE:
 					tag = "CREATE TYPE";
 					break;
 				default:

src/backend/tcop/utility.c

@@ -10,7 +10,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.190 2003/01/27 00:48:28 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/tcop/utility.c,v 1.191 2003/02/10 04:44:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -42,7 +42,6 @@
 #include "commands/view.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
-#include "parser/parse.h"
 #include "parser/parse_clause.h"
 #include "parser/parse_expr.h"
 #include "parser/parse_type.h"
@@ -261,9 +260,9 @@ ProcessUtility(Node *parsetree,
 			{
 				TransactionStmt *stmt = (TransactionStmt *) parsetree;
 
-				switch (stmt->command)
+				switch (stmt->kind)
 				{
-					case BEGIN_TRANS:
+					case TRANS_STMT_BEGIN:
 						BeginTransactionBlock();
 						break;
 
@@ -272,7 +271,7 @@ ProcessUtility(Node *parsetree,
 						 * Identical to BEGIN, except that it takes a few
 						 * additional options.
 						 */
-					case START:
+					case TRANS_STMT_START:
 						{
 							BeginTransactionBlock();
 
@@ -295,11 +294,11 @@ ProcessUtility(Node *parsetree,
 						}
 						break;
 
-					case COMMIT:
+					case TRANS_STMT_COMMIT:
 						EndTransactionBlock();
 						break;
 
-					case ROLLBACK:
+					case TRANS_STMT_ROLLBACK:
 						UserAbortTransactionBlock();
 						break;
 				}
@@ -320,17 +319,10 @@ ProcessUtility(Node *parsetree,
 		case T_FetchStmt:
 			{
 				FetchStmt  *stmt = (FetchStmt *) parsetree;
-				char	   *portalName = stmt->portalname;
-				bool		forward;
-				long		count;
 
-				forward = (bool) (stmt->direction == FORWARD);
-
-				/*
-				 * parser ensures that count is >= 0
-				 */
-				count = stmt->howMany;
-				PerformPortalFetch(portalName, forward, count,
+				PerformPortalFetch(stmt->portalname,
+								   stmt->direction == FETCH_FORWARD,
+								   stmt->howMany,
 								   (stmt->ismove) ? None : dest,
 								   completionTag);
 			}
@@ -693,17 +685,17 @@ ProcessUtility(Node *parsetree,
 			{
 				DefineStmt *stmt = (DefineStmt *) parsetree;
 
-				switch (stmt->defType)
+				switch (stmt->kind)
 				{
-					case OPERATOR:
+					case DEFINE_STMT_AGGREGATE:
+						DefineAggregate(stmt->defnames, stmt->definition);
+						break;
+					case DEFINE_STMT_OPERATOR:
 						DefineOperator(stmt->defnames, stmt->definition);
 						break;
-					case TYPE_P:
+					case DEFINE_STMT_TYPE:
 						DefineType(stmt->defnames, stmt->definition);
 						break;
-					case AGGREGATE:
-						DefineAggregate(stmt->defnames, stmt->definition);
-						break;
 				}
 			}
 			break;
@@ -981,17 +973,17 @@ ProcessUtility(Node *parsetree,
 			{
 				ReindexStmt *stmt = (ReindexStmt *) parsetree;
 
-				switch (stmt->reindexType)
+				switch (stmt->kind)
 				{
-					case INDEX:
+					case REINDEX_INDEX:
 						CheckOwnership(stmt->relation, false);
 						ReindexIndex(stmt->relation, stmt->force);
 						break;
-					case TABLE:
+					case REINDEX_TABLE:
 						CheckOwnership(stmt->relation, false);
 						ReindexTable(stmt->relation, stmt->force);
 						break;
-					case DATABASE:
+					case REINDEX_DATABASE:
 						ReindexDatabase(stmt->name, stmt->force, false);
 						break;
 				}

src/include/nodes/makefuncs.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: makefuncs.h,v 1.43 2002/12/12 15:49:40 tgl Exp $
+ * $Id: makefuncs.h,v 1.44 2003/02/10 04:44:46 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -17,10 +17,11 @@
 #include "nodes/parsenodes.h"
 
 
-extern A_Expr *makeA_Expr(int oper, List *name, Node *lexpr, Node *rexpr);
+extern A_Expr *makeA_Expr(A_Expr_Kind kind, List *name,
+						  Node *lexpr, Node *rexpr);
 
-extern A_Expr *makeSimpleA_Expr(int oper, const char *name,
-				 Node *lexpr, Node *rexpr);
+extern A_Expr *makeSimpleA_Expr(A_Expr_Kind kind, const char *name,
+								Node *lexpr, Node *rexpr);
 
 extern Var *makeVar(Index varno,
 		AttrNumber varattno,

src/include/nodes/parsenodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2002, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: parsenodes.h,v 1.228 2003/02/09 06:56:28 tgl Exp $
+ * $Id: parsenodes.h,v 1.229 2003/02/10 04:44:47 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -165,15 +165,25 @@ typedef struct ParamRef
 } ParamRef;
 
 /*
- * A_Expr - binary expressions
+ * A_Expr - infix, prefix, and postfix expressions
  */
+typedef enum A_Expr_Kind
+{
+	AEXPR_OP,					/* normal operator */
+	AEXPR_AND,					/* booleans - name field is unused */
+	AEXPR_OR,
+	AEXPR_NOT,
+	AEXPR_DISTINCT,				/* IS DISTINCT FROM - name must be "=" */
+	AEXPR_OF					/* IS (not) OF - name must be "=" or "!=" */
+} A_Expr_Kind;
+
 typedef struct A_Expr
 {
 	NodeTag		type;
-	int			oper;			/* type of operation (OP,OR,AND,NOT) */
+	A_Expr_Kind	kind;			/* see above */
 	List	   *name;			/* possibly-qualified name of operator */
-	Node	   *lexpr;			/* left argument */
-	Node	   *rexpr;			/* right argument */
+	Node	   *lexpr;			/* left argument, or NULL if none */
+	Node	   *rexpr;			/* right argument, or NULL if none */
 } A_Expr;
 
 /*
@@ -1058,13 +1068,20 @@ typedef struct CreateSeqStmt
 } CreateSeqStmt;
 
 /* ----------------------
- *		Create {Operator|Type|Aggregate} Statement
+ *		Create {Aggregate|Operator|Type} Statement
  * ----------------------
  */
+typedef enum DefineStmtKind
+{
+	DEFINE_STMT_AGGREGATE,
+	DEFINE_STMT_OPERATOR,
+	DEFINE_STMT_TYPE
+} DefineStmtKind;
+
 typedef struct DefineStmt
 {
 	NodeTag		type;
-	int			defType;		/* OPERATOR|TYPE_P|AGGREGATE */
+	DefineStmtKind kind;		/* see above */
 	List	   *defnames;		/* qualified name (list of Value strings) */
 	List	   *definition;		/* a list of DefElem */
 } DefineStmt;
@@ -1196,11 +1213,18 @@ typedef struct CommentStmt
  *		Fetch Statement
  * ----------------------
  */
+typedef enum FetchDirection
+{
+	FETCH_FORWARD,
+	FETCH_BACKWARD
+	/* ABSOLUTE someday? */
+} FetchDirection;
+
 typedef struct FetchStmt
 {
 	NodeTag		type;
-	int			direction;		/* FORWARD or BACKWARD */
-	long		howMany;		/* amount to fetch */
+	FetchDirection direction;	/* see above */
+	long		howMany;		/* number of rows */
 	char	   *portalname;		/* name of portal (cursor) */
 	bool		ismove;			/* TRUE if MOVE */
 } FetchStmt;
@@ -1357,11 +1381,19 @@ typedef struct UnlistenStmt
  *		{Begin|Commit|Rollback} Transaction Statement
  * ----------------------
  */
+typedef enum TransactionStmtKind
+{
+	TRANS_STMT_BEGIN,
+	TRANS_STMT_START,			/* semantically identical to BEGIN */
+	TRANS_STMT_COMMIT,
+	TRANS_STMT_ROLLBACK
+} TransactionStmtKind;
+
 typedef struct TransactionStmt
 {
 	NodeTag		type;
-	int			command;		/* BEGIN_TRANS|START|COMMIT|ROLLBACK */
-	List	   *options;
+	TransactionStmtKind kind;	/* see above */
+	List	   *options;		/* for BEGIN/START only */
 } TransactionStmt;
 
 /* ----------------------
@@ -1544,10 +1576,17 @@ typedef struct ConstraintsSetStmt
  *		REINDEX Statement
  * ----------------------
  */
+typedef enum ReindexStmtKind
+{
+	REINDEX_INDEX,
+	REINDEX_TABLE,
+	REINDEX_DATABASE
+} ReindexStmtKind;
+
 typedef struct ReindexStmt
 {
 	NodeTag		type;
-	int			reindexType;	/* INDEX|TABLE|DATABASE */
+	ReindexStmtKind kind;		/* see above */
 	RangeVar   *relation;		/* Table or index to reindex */
 	const char *name;			/* name of database to reindex */
 	bool		force;