feat: abstract value for IR

include/ir/value.hpp

@@ -0,0 +1,26 @@
+#pragma once
+#include "prelude/string.hpp"
+
+namespace IR
+{
+
+class Value
+{
+public:
+    Value(unsigned int id) : m_id(id) {}
+    Value() : m_id(0) {}
+public:
+    StringView Format() const
+    {
+        auto sb = StringBuilder();
+        sb.AppendFormat("%%%d", m_id);
+        return sb.view();
+    }
+private:
+    unsigned int m_id;
+};
+
+using ValueView = View<Value>;
+using ValueBuilder = Builder<Value>;
+
+} // namespace IR