1 files changed, 5 insertions, 1 deletions
diff --git a/expression.go b/expression.go
index 0498d35..6ae3399 100644
--- a/expression.go
+++ b/expression.go
@@ -1,6 +1,9 @@
 package main
 
-import "fmt"
+import (
+	"fmt"
+	"io"
+)
 
 type expression interface {
 	markExpr()
@@ -97,6 +100,7 @@ func (r *returnStmt) line() int { return r.ln }
 type exprExpr interface {
 	expression
 	markExprExpr()
+	generate(io.Writer) (string, error)
 }
 
 type equalityExpr struct {