Building FSON Parsing and Serialization into Fossil Tofu

In my previous reflection on Fossil Tofu, I discussed its evolving design and the decision to make FSON a first-class citizen in the library. Today, I want to share my thoughts on one of the most ambitious goals for the project: giving every major data structure in Fossil Tofu the ability to parse and serialize FSON data directly. This is not just a convenience feature—this is a commitment to making Fossil Tofu a bridge between in-memory structures and Fossil Logic’s persistent data format.

Why FSON Support Matters

FSON was designed to be more than just another serialization format. It is compact, predictable, and binary-safe, making it ideal for storage and transmission in performance-sensitive systems. Where JSON is human-readable but verbose, and where other formats can be overly rigid, FSON strikes a careful balance. By building FSON support directly into Fossil Tofu, I am making it possible for developers to go from a persisted FSON file to a fully populated in-memory data structure with a single call—and back again.

This approach eliminates the boilerplate that so often accompanies deserialization in C. Instead of manually writing parsers for each data type, developers will be able to rely on Fossil Tofu to do the heavy lifting. This is a core principle for me: reducing friction so that the focus remains on solving the real problem, not reinventing serialization logic for every project.

Parsing FSON into Data Structures

The first step is designing a parser interface that can walk a FSON document and fill out a given data structure. For example, a tree can be reconstructed node by node based on hierarchical keys, an array can be filled from a sequential FSON array, and a hash map can be populated by pairing keys and values from FSON objects.

This means Fossil Tofu will need a small, focused FSON reader capable of traversing the data efficiently. I am leaning toward a callback-driven parser that allows each data structure to “subscribe” to the portions of the FSON it cares about. This keeps the parsing process modular and flexible, ensuring that new structures can be added later without rewriting the core parser.

Serializing Back into FSON

Just as important as parsing is the ability to serialize data back into FSON. Persistence is a two-way street. When a program shuts down, I want developers to be able to dump their in-memory data structures back into FSON for storage, caching, or logging. This symmetry between parse and serialize keeps data lifecycles predictable and avoids the mismatch that sometimes plagues other serialization systems where the “read” and “write” paths are not guaranteed to produce equivalent representations.

Serialization also opens the door for powerful debugging tools. Imagine dumping the entire contents of an array list or tree to a FSON file and analyzing it with other Fossil Logic tools—suddenly, what used to be opaque data becomes visible, portable, and easy to inspect.

A Unique Way to Load Structures

By tightly integrating FSON support, Fossil Tofu will offer a unique loading mechanism for developers. Instead of starting with empty containers and manually pushing data in, developers will be able to say, “Here is a FSON file—populate this structure.” It is a direct and elegant way to hydrate in-memory data from persistent state.

This is especially exciting for use cases where data needs to be shared between different tools or even different languages, as FSON is portable and not tied to C specifically. This feature will turn Fossil Tofu from a collection of structures into a data interchange layer, bridging disk and memory in a way that feels natural.

The Road Ahead

There is still work to do. The parser needs to be efficient and minimalistic, the serializer must be able to output FSON in a streaming-friendly way, and the API must remain clean and consistent across all supported structures. But the vision is clear: Fossil Tofu will not just store data, it will understand data.

This is the next step in building a library that developers can rely on not only for runtime storage but also for persistence and portability. I am looking forward to the day when loading a tree or dumping an array list is as simple as calling a single function—because that is the level of simplicity I want Fossil Tofu to deliver.