add src/coders/obj

src/data/dynamic.hpp

@@ -3,6 +3,7 @@
 
 #include "../typedefs.hpp"
 
+#include <cmath>
 #include <string>
 #include <vector>
 #include <memory>
@@ -47,6 +48,15 @@ namespace dynamic {
                std::holds_alternative<integer_t>(value);
     }
 
+    inline number_t as_number(const Value& value) {
+        if (auto num = std::get_if<number_t>(&value)) {
+            return *num;
+        } else if (auto num = std::get_if<integer_t>(&value)) {
+            return *num;
+        }
+        return NAN;
+    }
+
     class List {
     public:
         std::vector<Value> values;