gen4: plan more opcodes

go/vt/sqlparser/ast.go

@@ -1794,8 +1794,8 @@ type (
 
 	// IsExpr represents an IS ... or an IS NOT ... expression.
 	IsExpr struct {
-		Operator IsExprOperator
-		Expr     Expr
+		Left  Expr
+		Right IsExprOperator
 	}
 
 	// IsExprOperator is an enum for IsExpr.Operator

go/vt/sqlparser/ast_format.go

@@ -960,7 +960,7 @@ func (node *RangeCond) Format(buf *TrackedBuffer) {
 
 // Format formats the node.
 func (node *IsExpr) Format(buf *TrackedBuffer) {
-	buf.astPrintf(node, "%v %s", node.Expr, node.Operator.ToString())
+	buf.astPrintf(node, "%v %s", node.Left, node.Right.ToString())
 }
 
 // Format formats the node.

go/vt/sqlparser/precedence_test.go

@@ -35,7 +35,7 @@ func readable(node Expr) string {
 	case *BinaryExpr:
 		return fmt.Sprintf("(%s %s %s)", readable(node.Left), node.Operator.ToString(), readable(node.Right))
 	case *IsExpr:
-		return fmt.Sprintf("(%s %s)", readable(node.Expr), node.Operator.ToString())
+		return fmt.Sprintf("(%s %s)", readable(node.Left), node.Right.ToString())
 	default:
 		return String(node)
 	}

go/vt/sqlparser/random_expr.go

@@ -314,7 +314,7 @@ func (g *generator) isExpr() Expr {
 	ops := []IsExprOperator{IsNullOp, IsNotNullOp, IsTrueOp, IsNotTrueOp, IsFalseOp, IsNotFalseOp}
 
 	return &IsExpr{
-		Operator: ops[g.r.Intn(len(ops))],
-		Expr:     g.booleanExpr(),
+		Right: ops[g.r.Intn(len(ops))],
+		Left:  g.booleanExpr(),
 	}
 }

go/vt/sqlparser/sql.y

@@ -3513,7 +3513,7 @@ expression:
   }
 | expression IS is_suffix
   {
-    $$ = &IsExpr{Operator: $3, Expr: $1}
+    $$ = &IsExpr{Left: $1, Right: $3}
   }
 | value_expression
   {

go/vt/vtgate/planbuilder/route.go

@@ -668,11 +668,11 @@ func (rb *route) computeEqualPlan(pb *primitiveBuilder, comparison *sqlparser.Co
 // computeIS computes the plan for an equality constraint.
 func (rb *route) computeISPlan(pb *primitiveBuilder, comparison *sqlparser.IsExpr) (opcode engine.RouteOpcode, vindex vindexes.SingleColumn, expr sqlparser.Expr) {
 	// we only handle IS NULL correct. IsExpr can contain other expressions as well
-	if comparison.Operator != sqlparser.IsNullOp {
+	if comparison.Right != sqlparser.IsNullOp {
 		return engine.SelectScatter, nil, nil
 	}
 
-	vindex = pb.st.Vindex(comparison.Expr, rb)
+	vindex = pb.st.Vindex(comparison.Left, rb)
 	// fallback to scatter gather if there is no vindex
 	if vindex == nil {
 		return engine.SelectScatter, nil, nil