diff --git a/ast/ast.go b/ast/ast.go
new file mode 100644
index 0000000..e74f29f
--- /dev/null
+++ b/ast/ast.go
@@ -0,0 +1,9 @@
+package ast
+
+type Statement interface {
+	stmt()
+}
+
+type Expr interface {
+	expr()
+}
diff --git a/ast/expr.go b/ast/expr.go
new file mode 100644
index 0000000..85ae501
--- /dev/null
+++ b/ast/expr.go
@@ -0,0 +1,13 @@
+package ast
+
+//binary
+////number expr
+////string expr
+////symbol expr
+////assignment
+
+//complex
+/////binary expr
+////filter expr????
+////call expr
+////pipe expr