feat: moving checksum to sources directory, update file structure.

Signed-off-by: Amlal El Mahrouss <amlal@nekernel.org>

3 files changed, 46 insertions, 2 deletions

diff --git a/src/fix/checksum.cpp b/src/fix/checksum.cpp
new file mode 100644
index 0000000..e8e155f
--- /dev/null
+++ b/src/fix/checksum.cpp
@@ -0,0 +1,44 @@
+/*
+ * File: fix/checksum.cpp
+ * Purpose: Financial Information Exchange parser in C++
+ * Author: Amlal El Mahrouss (amlal@nekernel.org)
+ * Copyright 2026, Amlal El Mahrouss, licensed under the Boost Software License.
+ */
+
+#include <ocl/fix/checksum.hpp>
+
+namespace ocl::fix
+{
+
+	std::string try_index_checksum(range_buffer& fix)
+	{
+		if (fix.is_valid())
+			return fix["10"];
+		else
+			detail::throw_runtime_error();
+
+    detail::unreachable();
+
+		return {};
+	}
+
+	namespace operators
+	{
+
+		checksum_type
+		checksum(const boost::string_view& in_) noexcept
+		{
+			checksum_type cks{};
+
+			for (std::size_t idx{};
+				 idx < in_.size(); ++idx)
+				cks += static_cast<uint8_t>(in_[idx]);
+
+			// add \0
+			cks += 1;
+			return cks % 256;
+		}
+
+	} // namespace operators
+
+} // namespace ocl::fix
diff --git a/src/fix/parser_impl.cpp b/src/fix/parser.cpp
index 4db9873..d12056b 100644
--- a/src/fix/parser_impl.cpp
+++ b/src/fix/parser.cpp
@@ -1,5 +1,5 @@
 /*
- * File: fix/parser_impl.cpp
+ * File: fix/parser.cpp
  * Purpose: Financial Information Exchange parser in C++
  * Author: Amlal El Mahrouss (amlal@nekernel.org)
  * Copyright 2025-2026, Amlal El Mahrouss, licensed under the Boost Software License.
@@ -84,7 +84,7 @@ namespace ocl::fix
 	visitor::visitor()	= default;
 	visitor::~visitor() = default;
 
-	/// \brief Alias of visit.
+	/// @brief Alias of visit.
 	range_buffer visitor::operator()(const std::string& in)
 	{
 		return impl_->visit(in.data());
diff --git a/src/test/.keep b/src/test/.keep
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/src/test/.keep