solverforge 0.20.x: Guided Search and Grouped-Scalar Neighborhoods

solverforge 0.20.x follows solverforge 0.19.14 and was published on crates.io (2026-10-12 through 2026-10-13). The line starts with accepted-count foraging and covers patches through 0.20.4. Rust 1.95 remains the workspace floor. For the current manuals, use the core overview and 0.21.x release note.

What Changed

Accepted-count foraging and pooled scratch (0.20.0–0.20.2)

Grouped-scalar default local search uses AcceptedCount(256): each step compares up to 256 accepted candidates, or drains the union, before applying the best. Explicitly configured foragers keep their chosen policy. The previous default stepped with FirstLastStepScoreImproving and no cap, stopping at the first step-improving candidate and discarding the remaining accepted work; the forager change alters default search depth, not a configuration contract.

Precedence-route cycle checks, precedence scoring, and grouped-scalar construction reuse scratch buffers. Construction and search batch inner-loop control polls and latch observed stop requests; phase-boundary limits remain binding. Assignment indexes recycle empty row buffers, and fully forced rule edges avoid redundant membership reads. These patches do not add model APIs.

Guided native scalar search (0.20.3)

search_entity_order_key and search_value_order_key on #[planning_variable], with matching ScalarVariableSlot builders, guide native change enumeration. Swap uses the entity key for its left traversal. Lower keys are tried first, equal keys retain seeded order, and missing keys sort last. Construction-order hooks remain construction-only. Construction also reuses rule verdicts already computed during blocker discovery.

Score-authoritative neighborhoods and late acceptance (0.20.4)

Grouped-scalar families use pressure and scarcity to order bounded discovery, not to replace the model’s score. The final edit set still obeys domains, required rows, capacity, and assignment rules; the score, acceptor, and forager decide among legal candidates. Families share the candidate budget by round-robin pulls. Pair and cycle coordinates stream without eager Cartesian materialization or unrelated internal walk cutoffs.

Sparse hypothetical overlays preserve committed membership during augmenting, ejection/reinsert, and required-batch discovery. Final validation subtracts departures before arrivals and checks post-edit sequence edges, including vacated source edges.

Diversified late acceptance accepts equality with the step score or strict improvement over the worst history score. Its ring advances per evaluated candidate, with exact worst-score occurrence tracking; the former tolerance configuration and with_default_tolerance constructor are removed. Plain late acceptance resets its entire history on a new phase-best score.

Published Version Boundaries

Surface	Version	Notes
Historical core line	solverforge 0.20.0–0.20.4	Rust 1.95; use matching source and crate APIs; 0.20.0–0.20.1 registry and release artifacts remain available for those patches
CLI	solverforge-cli 3.3.3	Scaffolds core 0.19.7, UI 0.9.0, maps 2.1.4, MCP rmcp 3.5.0
Python	solverforge-py 0.6.10 / PyPI solverforge 0.6.10	Runtime 0.19.7 and UI 0.9.0
Worked use cases	Eight released apps	Runtime 0.19.7 and UI 0.9.0

Independent CLI, Python, and app packages do not inherit a core upgrade.

Patch History

Version	Date	Notes
0.20.4	2026-10-13	Score-authoritative grouped-scalar neighborhoods, steered family budgets, sparse final-edit validation, corrected DLAS and best-anchored late acceptance; removes DLAS tolerance.
0.20.3	2026-10-12	Native scalar search_entity_order_key / search_value_order_key hooks and reuse of blocker rule verdicts.
0.20.2	2026-10-12	Batched control polls, recycled assignment-index rows, and forced-edge short-circuiting; no new model API.
0.20.1	2026-10-12	Pooled precedence-route and grouped-scalar construction scratch; no API change.
0.20.0	2026-10-12	Grouped-scalar default local search forages with AcceptedCount(256); no API change.
0.19.14	2026-10-12	Dense-key existence bookkeeping and the borrowed-row key rule on every later chained join.
0.19.13	2026-10-11	Per-key occurrence existence engine and caller-owned notification buffers.

Upgrade Checklist

• Remove DLAS tolerance settings and replace custom uses of the removed tolerance constructor with DiversifiedLateAcceptanceAcceptor::new(size).
• Compare late-acceptance and grouped-scalar solve quality at your own time limit; candidate ordering and acceptance trajectories can differ.
• Use search-order hooks for local-search guidance, not construction hooks.
• Upgrade CLI-generated apps deliberately: CLI 3.3.3 still targets core 0.19.7.
• For an upgrade to the current source line, follow the 0.21.x checklist.

Where to read next

Read Local Search and Configuration. The full 0.20.x range and upstream changelog record the patch boundaries.