use Call, remove FnCallExpr

ast.go

@@ -44,7 +44,6 @@ func (*StringLit) node()       {}
 func (*TableName) node()       {}
 func (*Type) node()            {}
 func (*UnaryExpr) node()       {}
-func (*FnCallExpr) node()      {}
 func (*UpdateStatement) node() {}
 func (*UpsertClause) node()    {}
 func (*UsingConstraint) node() {}
@@ -94,7 +93,6 @@ func (*QualifiedRef) expr() {}
 func (*Range) expr()        {}
 func (*StringLit) expr()    {}
 func (*UnaryExpr) expr()    {}
-func (*FnCallExpr) expr()   {}
 
 // ExprString returns the string representation of expr.
 // Returns a blank string if expr is nil.
@@ -364,19 +362,6 @@ func (expr *UnaryExpr) String() string {
 	}
 }
 
-type FnCallExpr struct {
-	Fn Token // function
-	X  Expr  // param expression
-}
-
-func (expr *FnCallExpr) String() string {
-	paran, ok := expr.X.(*ParenExpr)
-	if ok {
-		return expr.Fn.String() + "(" + paran.X.String() + ")"
-	}
-	return expr.Fn.String() + "(" + expr.X.String() + ")"
-}
-
 type BinaryExpr struct {
 	X  Expr  // lhs
 	Op Token // operator

parser.go

@@ -946,8 +946,9 @@ func (p *Parser) parseOperand() (expr Expr, err error) {
 			if err != nil {
 				return nil, err
 			}
+			expr = expr.(*ParenExpr).X
 		}
-		return &FnCallExpr{Fn: VALUES, X: expr}, nil
+		return &Call{Name: &Ident{Name: "VALUES"}, Args: []Expr{expr}}, nil
 
 	case IDENT, QIDENT:
 		ident := identByNameAndTok(lit, tok)