added string function to all nodes of ast

src/ast/ast.hpp

@@ -5,14 +5,17 @@
 namespace ast {
     struct node {
         virtual std::string token_literal() const = 0;
+        virtual std::string str() const = 0;
         virtual ~node() = default;
     };
 
     struct statement : node {
         virtual std::string token_literal() const override = 0;
+        virtual std::string str() const override = 0;
     };
 
     struct expression : node {
         virtual std::string token_literal() const override = 0;
+        virtual std::string str() const override = 0;
     };
 } // namespace ast

src/ast/expressions/identifier.cpp

@@ -8,4 +8,8 @@ namespace ast {
     std::string identifier::token_literal() const {
         return token.literal;
     }
+
+    std::string identifier::str() const {
+        return value;
+    };
 } // namespace ast

src/ast/expressions/identifier.hpp

@@ -12,5 +12,6 @@ namespace ast {
         std::string value;
 
         std::string token_literal() const override;
+        std::string str() const override;
     };
 } // namespace ast

src/ast/program.cpp

@@ -1,5 +1,7 @@
 #include "program.hpp"
 
+#include <sstream>
+
 namespace ast {
     std::string program ::token_literal() const {
         if (statements.size() > 0)
@@ -11,4 +13,12 @@ namespace ast {
         for (const auto& ref : statements)
             delete ref;
     };
+
+    std::string program::str() const {
+        std::stringstream ss;
+        for (const auto& stmt : statements)
+            ss << stmt->str();
+
+        return ss.str();
+    };
 } // namespace ast

src/ast/program.hpp

@@ -9,7 +9,8 @@ namespace ast {
     struct program : public node {
         std::vector<statement*> statements;
         std::string token_literal() const override;
-        virtual std::string str() const override = 0;
+
+        virtual std::string str() const override;
 
         ~program();
     };

src/ast/statements/expression.cpp

@@ -1,5 +1,7 @@
 #include "expression.hpp"
 
+#include <sstream>
+
 namespace ast {
 
     expression_stmt::expression_stmt(token::token token)
@@ -13,4 +15,13 @@ namespace ast {
     expression_stmt::~expression_stmt() {
         delete expression;
     }
+
+    std::string expression_stmt::str() const {
+        std::stringstream ss;
+
+        if (expression != nullptr)
+            ss << expression->str();
+
+        return ss.str();
+    };
 } // namespace ast

src/ast/statements/expression.hpp

@@ -11,6 +11,7 @@ namespace ast {
         ast::expression* expression;
 
         std::string token_literal() const override;
+        std::string str() const override;
 
         ~expression_stmt();
     };

src/ast/statements/let.cpp

@@ -1,5 +1,7 @@
 #include "let.hpp"
 
+#include <sstream>
+
 namespace ast {
     let_stmt::let_stmt(token::token token)
         : token(std::move(token)),
@@ -14,4 +16,14 @@ namespace ast {
         delete name;
         delete value;
     };
+
+    std::string let_stmt::str() const {
+        std::stringstream ss;
+
+        ss << token_literal() << ' ' << name->str() << " = ";
+        if (value != nullptr)
+            ss << value->str();
+
+        return ss.str();
+    };
 } // namespace ast

src/ast/statements/let.hpp

@@ -13,6 +13,7 @@ namespace ast {
         expression* value;
 
         std::string token_literal() const override;
+        std::string str() const override;
 
         ~let_stmt();
     };

src/ast/statements/return.cpp

@@ -1,5 +1,7 @@
 #include "return.hpp"
 
+#include <sstream>
+
 namespace ast {
     return_stmt::return_stmt(token::token token)
         : token(std::move(token)),
@@ -12,4 +14,14 @@ namespace ast {
     return_stmt::~return_stmt() {
         delete value;
     };
+
+    std::string return_stmt::str() const {
+        std::stringstream ss;
+
+        ss << token_literal() << " ";
+        if (value != nullptr)
+            ss << value->str();
+
+        return ss.str();
+    };
 } // namespace ast

src/ast/statements/return.hpp

@@ -1,3 +1,4 @@
+#pragma once
 
 #include "ast/ast.hpp"
 #include "token/token.hpp"
@@ -10,6 +11,7 @@ namespace ast {
         expression* value;
 
         std::string token_literal() const override;
+        std::string str() const override;
 
         ~return_stmt();
     };

src/lexer/lexer.hpp

@@ -1,4 +1,5 @@
 #pragma once
+
 #include "token/token.hpp"
 
 #include <istream>