Cell Dataset

CellDataset<T> is a stack-friendly dataset using Cell for no_std / single-threaded pipelines.

Definition

pub struct CellDataset<T: Copy> {
    value: Cell<Option<T>>,
}

• Works only with Copy types (e.g. i32, f64, bool, u8)
• Uses Cell for interior mutability — no heap allocation, no locking
• Starts empty; loading before any save returns PondError::DatasetNotLoaded
• const fn new() — can be used in static or const contexts

Usage

let a = CellDataset::<i32>::new();
let b = CellDataset::<i32>::new();

let pipe = (
    Node { name: "n1", func: |v| (v * 2,), input: (&params.x,), output: (&a,) },
    Node { name: "n2", func: |v| (v + 1,), input: (&a,), output: (&b,) },
);

Thread safety

CellDataset implements Sync via an unsafe impl because the RunnableStep trait requires Send + Sync. This is safe only for single-threaded runners like SequentialRunner.

Do not use CellDataset with ParallelRunner. Use MemoryDataset instead for parallel pipelines.

no_std

CellDataset is the primary intermediate dataset for no_std environments. It requires no feature flags, no allocator, and no standard library. Combined with Param and the SequentialRunner, it forms the foundation of a no_std pipeline.

Limitations

• Only works with Copy types — cannot hold String, Vec, DataFrame, etc.
• Not safe for concurrent access — single-threaded use only
• No serialization of stored values — Serialize impl serializes as unit ()