Added the equivalence operator. The major index optimizations are done.

Notes:
1) Some optimizations will follow after more deep analysis.
2) The syntax "==" is not yet agreed on. I'd prefer it to be changed.

src/dsql/dsql.cpp

@@ -2039,6 +2039,9 @@ void DSQL_pretty(const dsql_nod* node, int column)
 	case nod_eql:
 		verb = "eql";
 		break;
+	case nod_equiv:
+		verb = "equiv";
+		break;
 	case nod_erase:
 		verb = "erase";
 		break;

src/dsql/dsql.tab.h

@@ -259,3 +259,4 @@
 #define IIF 515
 #define SCALAR_ARRAY 516
 #define CROSS 517
+#define EQUIV 518

src/dsql/gen.cpp

@@ -296,6 +296,9 @@ void GEN_expr( dsql_req* request, dsql_nod* node)
 	case nod_eql:
 		blr_operator = blr_eql;
 		break;
+	case nod_equiv:
+		blr_operator = blr_equiv;
+		break;
 	case nod_neq_all:
 	case nod_neq_any:
 	case nod_neq:

src/dsql/keywords.cpp

@@ -28,7 +28,7 @@
  *  Contributor(s):
  * 
  *
- *  $Id: keywords.cpp,v 1.34 2004-10-13 18:37:32 dimitr Exp $
+ *  $Id: keywords.cpp,v 1.35 2004-10-14 18:54:48 dimitr Exp $
  *
  */
 
@@ -55,6 +55,7 @@ static const TOK tokens[] = {
 	{EQL, "=", 1},
 	{GTR, ">", 1},
 	{GEQ, ">=", 1},
+	{EQUIV, "==", 2},
 	{ACTION, "ACTION", 1},
 	{ACTIVE, "ACTIVE", 1},
 	{ADD, "ADD", 1},

src/dsql/node.h

@@ -333,7 +333,8 @@ enum nod_t
 	nod_exec_block,		// EXECUTE BLOCK support
 	nod_param_val,		// default value for SP parameters support
 	nod_rows,	// ROWS support
-	nod_query_spec
+	nod_query_spec,
+	nod_equiv
 };
 
 typedef nod_t NOD_TYPE;

src/dsql/parse.y

@@ -507,13 +507,14 @@ static LexerState lex;
 %token IIF
 %token SCALAR_ARRAY
 %token CROSS
+%token EQUIV
 
 /* precedence declarations for expression evaluation */
 
 %left	OR
 %left	AND
 %left	NOT
-%left	'=' '<' '>' LIKE EQL NEQ GTR LSS GEQ LEQ NOT_GTR NOT_LSS
+%left	'=' '<' '>' LIKE EQL NEQ GTR LSS GEQ LEQ NOT_GTR NOT_LSS EQUIV
 %left	'+' '-'
 %left	'*' '/'
 %left	CONCATENATE
@@ -3473,6 +3474,8 @@ comparison_predicate : value '=' value
 			{ $$ = make_node (nod_geq, 2, $1, $3); }
 		| value NEQ value
 			{ $$ = make_node (nod_neq, 2, $1, $3); }
+		| value EQUIV value
+			{ $$ = make_node (nod_equiv, 2, $1, $3); }
 		;
 
 

src/dsql/pass1.cpp

@@ -728,6 +728,7 @@ dsql_nod* PASS1_node(dsql_req* request, dsql_nod* input, bool proc_flag)
 	case nod_udf:
 		return pass1_udf(request, input, proc_flag);
 
+	case nod_equiv:
 	case nod_eql:
 	case nod_neq:
 	case nod_gtr:
@@ -796,6 +797,7 @@ dsql_nod* PASS1_node(dsql_req* request, dsql_nod* input, bool proc_flag)
 			}
 			else {
 				switch (input->nod_type) {
+				case nod_equiv:
 				case nod_eql:
 				case nod_neq:
 				case nod_gtr:
@@ -927,6 +929,7 @@ dsql_nod* PASS1_node(dsql_req* request, dsql_nod* input, bool proc_flag)
 		sub3 = node->nod_arg[2];
 		// FALLINTO 
 	case nod_assign:
+	case nod_equiv:
 	case nod_eql:
 	case nod_gtr:
 	case nod_geq:
@@ -1806,6 +1809,7 @@ static bool aggregate_found2(const dsql_req* request, const dsql_nod* node,
 		case nod_or:
 		case nod_and:
 		case nod_not:
+		case nod_equiv:
 		case nod_eql:
 		case nod_neq:
 		case nod_gtr:
@@ -2550,6 +2554,7 @@ static bool invalid_reference(const dsql_ctx* context, const dsql_nod* node,
 		case nod_subtract2:
 		case nod_upcase:
 		case nod_extract:
+		case nod_equiv:
 		case nod_eql:
 		case nod_neq:
 		case nod_gtr:
@@ -4116,6 +4121,7 @@ static bool pass1_found_aggregate(const dsql_nod* node, USHORT check_scope_level
 		case nod_divide2:
 		case nod_multiply2:
 		case nod_subtract2:
+		case nod_equiv:
 		case nod_eql:
 		case nod_neq:
 		case nod_gtr:
@@ -4344,6 +4350,7 @@ static bool pass1_found_field(const dsql_nod* node, USHORT check_scope_level,
 		case nod_divide2:
 		case nod_multiply2:
 		case nod_subtract2:
+		case nod_equiv:
 		case nod_eql:
 		case nod_neq:
 		case nod_gtr:
@@ -6854,6 +6861,7 @@ static dsql_nod* remap_field(dsql_req* request, dsql_nod* field,
 		case nod_or:
 		case nod_and:
 		case nod_not:
+		case nod_equiv:
 		case nod_eql:
 		case nod_neq:
 		case nod_gtr: