sim-incremental-core 0.1.2

#![forbid(unsafe_code)]
#![deny(missing_docs)]
//! Generic incremental query calculation for SIM runtime libraries.
//!
//! `sim-incremental-core` records dependencies from actual query execution. A
//! query can read another query through its [`QueryFrame`], observe external
//! stamps, and return any hashable Rust value. The engine keeps memoized values,
//! reverse dependency edges, cycle paths, typed budget failures, continuation
//! tokens, and bounded graph snapshots without depending on SIM expressions,
//! codecs, Table/Dir storage, web surfaces, or expression-tree records.
//!
//! # Dataflow reuse and cycle boundary
//!
//! Dataflow extensions reuse this crate's existing ownership ledger instead of
//! defining parallel protocol types:
//!
//! - fingerprint: [`ValueFingerprint`]
//! - observation: [`Observation`]
//! - revision: [`Revision`]
//! - budget: [`QueryBudgets`]
//! - continuation: [`ContinuationToken`]
//! - snapshot: [`GraphSnapshot`]
//!
//! A cycle in a dataflow graph is valid when its edges carry monotone lattice
//! facts: repeatedly joining those facts must converge at a fixed point. That
//! worklist-level feedback does not recursively enter query callbacks. By
//! contrast, a query dependency cycle occurs when a [`QueryFrame::read`] tries
//! to re-enter a query already on the active query stack. It is a programming
//! error reported as [`IncrementalError::Cycle`], not a fixed-point request.
//!
//! # Examples
//!
//! ```
//! use sim_incremental_core::{IncrementalEngine, QueryResult};
//!
//! let mut engine = IncrementalEngine::<&'static str, i64>::new();
//! engine.register_fn("a", |_, _| Ok(1));
//! engine.register_fn("b", |_, frame| {
//!     let a = frame.read("a")?;
//!     Ok(a + 1)
//! });
//!
//! let value: QueryResult<_, _> = engine.verify("b");
//! assert_eq!(value.unwrap(), 2);
//! ```

mod budget;
pub mod dataflow;
mod engine;
mod error;
mod fingerprint;
mod observation;
mod query;
mod snapshot;
mod state;

pub use budget::{BudgetKind, QueryBudgets, SnapshotBudgets};
pub use engine::{IncrementalEngine, QueryFrame};
pub use error::{ContinuationToken, IncrementalError, SnapshotError};
pub use fingerprint::{FingerprintValue, ValueFingerprint};
pub use observation::{Observation, ObservationKind, Revision};
pub use query::{Query, QueryResult};
pub use snapshot::{GraphSnapshot, RestoreReport, SnapshotNode};

#[cfg(test)]
mod tests;