diff --git a/src/ast.rs b/src/ast.rs
index d79b436..cefc518 100644
--- a/src/ast.rs
+++ b/src/ast.rs
@@ -1,11 +1,38 @@
-pub mod AST {
-    pub enum NodeType {
-        Program,
-        NumericLiteral,
-        Identifier,
-        BinaryExpression,
-        CallExperssion,
-        UnaryExpression,
-        FunctionDeclaration,
-    }
+pub trait Stmt {}
+pub trait Expr: Stmt {}
+
+pub enum NodeType {
+    Program(Program),
+    NumericLiteral(NumericLiteral),
+    Identifier(Identifier),
+    BinaryExpr(BinaryExpr),
 }
+
+pub struct Program {
+    pub body: Vec<NodeType>,
+}
+
+pub struct BinaryExpr {
+    pub left: Box<NodeType>,
+    pub right: Box<NodeType>,
+    pub operator: String,
+}
+
+pub struct Identifier {
+    pub symbol: String,
+}
+
+pub struct NumericLiteral {
+    pub value: f64,
+}
+
+impl Stmt for Program {}
+
+impl Stmt for NumericLiteral {}
+impl Expr for NumericLiteral {}
+
+impl Stmt for Identifier {}
+impl Expr for Identifier {}
+
+impl Stmt for BinaryExpr {}
+impl Expr for BinaryExpr {}