Add default constructor to handle

Signed-off-by: CHatingPython <chatingpython@gmail.com>

furc/include/furc/ast/declaration.hpp

@@ -5,7 +5,6 @@
 #include "furc/ast/statement.hpp"
 #include "furc/front/token.hpp"
 
-#include <ostream>
 #include <vector>
 
 namespace furc {
@@ -42,9 +41,7 @@ public:
 
     front::token name() const { return m_name; }
 public:
-    std::ostream& print(std::ostream& os) const override {
-        return os << "function " << m_name->string << " declaration";
-    }
+    std::ostream& print(std::ostream& os) const override;
 protected:
     front::token m_name;
 };
@@ -74,16 +71,7 @@ public:
 
     const function_body_handle& body() const { return m_body; }
 public:
-    std::ostream& print(std::ostream& os) const override {
-        function_declarartion_node::print(os);
-        os << ':';
-        if (m_body.present()) {
-            for (const auto& entry : m_body->statements)
-                os << '\n' << entry;
-            return os << '\n' << m_body->end << ": " << m_name->string << " end";
-        }
-        return os << m_body.error(); // error
-    }
+    std::ostream& print(std::ostream& os) const override;
 private:
     function_body_handle m_body;
 };

furc/include/furc/ast/literal.hpp

@@ -5,8 +5,6 @@
 #include "furc/ast/node.hpp"
 #include "furc/front/token.hpp"
 
-#include <ostream>
-
 namespace furc {
 namespace ast {
 
@@ -50,10 +48,7 @@ public:
 
     const handle<front::integer_token>& value() const { return m_value; }
 public:
-    std::ostream& print(std::ostream& os) const override {
-        if (m_value.has_error()) return os << m_value.error();
-        return os << "integer literal (" << *m_value << ")";
-    }
+    std::ostream& print(std::ostream& os) const override;
 private:
     handle<front::integer_token> m_value;
 };

furc/include/furc/ast/program.hpp

@@ -4,7 +4,6 @@
 #include "furc/ast/declaration.hpp"
 #include "furc/ast/node.hpp"
 
-#include <ostream>
 #include <vector>
 
 namespace furc {
@@ -20,13 +19,7 @@ public:
 
     const std::vector<node_handle<declaration_node>>& declarations() const { return m_declarations; }
 public:
-    std::ostream& print(std::ostream& os) const override {
-        os << "program:";
-        for (const auto& handle : m_declarations) {
-            os << '\n' << handle;
-        }
-        return os;
-    }
+    std::ostream& print(std::ostream& os) const override;
 private:
     std::vector<node_handle<declaration_node>> m_declarations;
 };

furc/include/furc/ast/statement.hpp

@@ -3,8 +3,6 @@
 
 #include "furc/ast/node.hpp"
 
-#include <ostream>
-
 namespace furc {
 namespace ast {
 
@@ -21,13 +19,19 @@ public:
     virtual statement_node_t statement_type() const = 0;
 };
 
+class expression_node;
 class return_statement_node : public statement_node {
 public:
     return_statement_node() = default;
+
+    return_statement_node(node_handle<expression_node>&& value)
+      : m_value(std::move(value)) {}
 public:
     statement_node_t statement_type() const override { return statement_node_t::Return; }
 
-    std::ostream& print(std::ostream& os) const override { return os << "return statement"; }
+    std::ostream& print(std::ostream& os) const override;
+private:
+    node_handle<expression_node> m_value;
 };
 
 } // namespace ast