gerbil-ascent

Scheme-native ASCENT implementation built on Gerbil POO and POO Flow Core. gerbil.pkg declares Core as its sole direct package dependency; Core supplies the shared POO contracts used by the Scheme modules. The separate SS benchmark qualification uses ASP from the development test environment. Each top-level directory is a Gerbil module namespace:

Namespace	Current responsibility
:gerbil-ascent/program/*	Typed POO rule declarations and stratified evaluation
:gerbil-ascent/core/*	Indexed binary evaluation path
:gerbil-ascent/table/*	Binary relation indexes and projections
:gerbil-ascent/candidate/*	Experimental candidate and support projection
:gerbil-ascent/interface/*	Inert request projection

program/ exposes POO relation, lattice, atom, negation, guard, binding, aggregate, and Standard Library iterable generator clauses with scalar or tuple outputs. A slot Generic lowers each clause to a private execution plan; count, sum, min, max, mean, and custom aggregate procedures run over matched tuples. Lattice declarations join the last column for equal prefix keys and propagate improvements through the same fixed point. Generic relation clauses plan bound columns and use a cached table index when the relation has at least 32 rows. table/interface.ss exposes a POO index Provider; a custom provider can replace the physical index without changing the rule program. The BYODS storage Provider creates private state for each relation evaluation. The eqrel implementation maintains component membership and emits new cross-component facts when an edge joins two components. The trrel and trrel_uf implementations index known predecessors and successors per relation run, preserving explicit self facts and grouped keys. Guards, bindings, and generators declare their input variables explicitly, and rule bodies check bindings in source order. The evaluator reads validated clause slots once per run before iterating relation rows.

gerbil-ascent-open-session retains relation rows, indexes, BYODS state, and semi-naive deltas across calls to gerbil-ascent-session-run. After the first run, gerbil-ascent-session-append-source! accepts source rows for programs whose rule bodies contain only positive relation atoms. Each run returns a stable POO result snapshot; an unchanged run returns its previous result. Negation, aggregation, lattice updates, and source deletion still require a fresh program evaluation. The one-shot gerbil-ascent-evaluate-program uses the same evaluator.

t/ contains Scheme qualification; rust/ascent-oracle/ contains the test-only Rust Ascent differential oracle. The parity matrix tracks the unfinished Rust 0.8.0 feature surface. Complete Scheme parity is the gate before new Agent-specific extensions. POO Flow consumes this package as a pinned submodule. MRR owns the semantic adapter and admission of its own evidence.

The related-work matrix maps the Ascent papers and adjacent research on incremental updates, monotonicity, equality, constraints, and provenance to concrete parity and Agent research questions.

Scheme qualification extends Core's Observability Case profile with ASCENT-specific memory and duration budgets; it does not own a test runner.

gerbil deps --install
gerbil build
just test
just oracle

The Rust oracle is a qualification dependency, not part of the Scheme runtime.

Credits and copyright

This project builds on the research ideas and published semantics of Ascent:

• Arash Sahebolamri, Thomas Gilray, and Kristopher Micinski, “Seamless Deductive Inference via Macros”, CC 2022.
• Arash Sahebolamri, Langston Barrett, Scott Moore, and Kristopher Micinski, “Bring Your Own Data Structures to Datalog”, Proceedings of the ACM on Programming Languages, OOPSLA2 2023.

The differential oracle depends on the upstream Ascent Rust project and ascent-byods-rels 0.8.0. Copyright in that project belongs to its individual contributors; its source license is MIT. The papers retain their authors' and publishers' rights. Citations here acknowledge their research; the papers are not redistributed in this repository. The other cited papers and their authors are listed in the related-work bibliography.

The Scheme implementation and repository-authored qualification code are copyright © 2026 tao3k team and Contributors and are licensed under Apache-2.0 AND LGPL-2.1-or-later, as stated in LICENSE and the source file SPDX headers. That project license does not change the upstream project's license or the papers' rights.