moved program to it's own files

src/ast/ast.hpp

@@ -1,7 +1,6 @@
 #pragma once
 
 #include <string>
-#include <vector>
 
 namespace ast {
     struct node {
@@ -16,14 +15,4 @@ namespace ast {
     struct expression : node {
         virtual std::string token_literal() const override = 0;
     };
-
-    struct program : public node {
-        std::vector<statement*> statements;
-        std::string token_literal() const override;
-
-        ~program() {
-            for (const auto& ref : statements)
-                delete ref;
-        };
-    };
 } // namespace ast

src/ast/program.cpp

@@ -1,4 +1,4 @@
-#include "ast.hpp"
+#include "program.hpp"
 
 namespace ast {
     std::string program ::token_literal() const {
@@ -6,4 +6,9 @@ namespace ast {
             return statements[0]->token_literal();
         return "";
     }
+
+    program::~program() {
+        for (const auto& ref : statements)
+            delete ref;
+    };
 } // namespace ast

src/ast/program.hpp

@@ -0,0 +1,16 @@
+#pragma once
+
+#include "ast.hpp"
+
+#include <string>
+#include <vector>
+
+namespace ast {
+    struct program : public node {
+        std::vector<statement*> statements;
+        std::string token_literal() const override;
+        virtual std::string str() const override = 0;
+
+        ~program();
+    };
+} // namespace ast