FcaBedrock vNext

A ground-up .NET 10 rewrite of FcaBedrock, a preprocessing tool for Formal Concept Analysis (FCA). It ingests structured data, applies a user-curated Bedrock spec describing how raw values become formal-context attributes via conceptual scaling, and emits deterministic Burmeister .cxt and FIMI .dat formal-context files for downstream FCA tools (ConExp, In-Close, etc.).

The design centres on one idea: discretization and scaling are orthogonal. A discretizer maps a raw value to a bin label; a scale maps a bin label to zero or more formal attributes. Every legacy attribute "type" is a (discretizer, scale) pair, and new combinations fall out for free.

Under active development. M1–M8 are complete. The pipeline reproduces FcaBedrock v2 byte-for-byte on the mini-mushroom and mini-adult fixture families (under --v2-compat).

Implemented today:

• Input: wide CSV/TSV and subject-predicate-value triple sources.
• Specs: legacy .bed and the native TOML format: round-trip, composition (extends), templates and matchers, the three plan-derived fingerprints, and one-way .bed → TOML migration.
• Conversion: every v1 discretizer kind, calibration, and restrict_to.
• Output: deterministic .cxt/.dat, with a --v2-compat preset.
• Discovery: probe draft-spec generation for both wide and triple sources, as a library API and as the probe command.
• CLI: the fcabedrock command, shipping all eight commands (convert, validate, plan, stats, calibrate, probe, migrate and fingerprint) with the run manifest, the publication transaction, and the freeze engine.

M8, the scaling and benchmark pass, added an internal BenchmarkDotNet suite over the real production paths, target-scale evidence at 7.3M and 73M input records, a self-contained standalone distribution beside the global tool, and per-platform build, test, accounting, and packaging checks. Its follow-up, M8.1, changed how count-sensitive (equal-frequency and percentile) calibration schedules its spill runs without changing its results. M8.2, the writing, ownership and provenance hardening pass, is complete, integrated on main and accepted. M8.3, which corrects the command-line tool's behaviour and makes its diagnostics usable, is complete, integrated on main and accepted. The desktop UI (M9) is in progress: its contract is recorded, the run coordinator is extracted into a shared package, progress observation and the cancellation contract are implemented in it, and no desktop code exists yet.

docs/roadmap.md is the live source for the detailed current position, and docs/benchmarks.md is the measurement record.

Every push to main and every pull request targeting it builds, tests, checks resident-memory accounting, smoke-tests both distributions, and produces a tested archive on each supported native target: Windows x64, Linux x64, and macOS ARM64. Linux ARM64 and Windows ARM64 also run where available; they carry no support claim and produce no distribution archive.

The workflow is .github/workflows/ci.yml. It is deliberately not a performance measurement: hosted runners are shared and of unstated provenance, so the only benchmark step there is a Dry run that executes each Small-category case once and measures nothing. Comparative performance belongs to controlled, identified hardware and is recorded in docs/benchmarks.md.

Every input those jobs need comes from this repository: the benchmark corpora they prepare are generated from pinned arithmetic. The one corpus that is downloaded rather than generated (the UCI Adult training split) is deliberately outside routine CI, so an outage at a research-data host cannot fail a build that has nothing to do with it. Its cases are run explicitly on the release candidate instead, which docs/benchmarks.md records.

Each run of the three required targets uploads its self-contained archive as a build artifact, retained for seven days.

FcaBedrock.Cli is a technical preview. It is not yet published to a public NuGet feed, so the global-tool command below applies only once the package is available on a NuGet source you have configured.

Install the .NET 10 SDK first. On Windows:

winget install Microsoft.DotNet.SDK.10

On other platforms, install the .NET 10 SDK by the method your platform documents.

Then, once the package is available on a configured NuGet source:

dotnet tool install --global FcaBedrock.Cli

Until it is published, install it from a local pack of this repository, the same package the installed-tool smoke test installs under --tool-path:

dotnet pack src/FcaBedrock.Cli/FcaBedrock.Cli.csproj -c Release -o <dir>
dotnet tool install --global --add-source <dir> FcaBedrock.Cli

Check the installation, and read the full grammar:

fcabedrock --version
fcabedrock --help

To remove it:

dotnet tool uninstall --global FcaBedrock.Cli

Per-command usage: see the packed command guide.

The global tool is framework-dependent: it needs a matching .NET runtime on the machine. The standalone distribution does not; it carries the runtime beside the executable.

Build one for your platform:

./eng/publish-selfcontained.ps1

That writes artifacts/publish/<rid>/ and artifacts/publish/fcabedrock-<rid>.zip. Unzip it anywhere and run the executable directly; it keeps its assembly name, FcaBedrock.Cli (.exe on Windows), because the fcabedrock command name belongs to the global-tool shim.

./FcaBedrock.Cli --version
./FcaBedrock.Cli convert spec.toml data.csv --out out/context --format both

The required archives are win-x64, linux-x64, and osx-arm64, and CI produces each of them on its own platform, then extracts that exact archive and runs the extracted executable before uploading it; a cross-published folder shows only that the SDK can emit files for another target, not that the result runs there. On Linux and macOS the archive records FcaBedrock.Cli as executable, so ./FcaBedrock.Cli works straight out of the unzip. "Self-contained" bundles .NET, not the operating system: globalization still uses the host's ICU, which Windows 10+ ships and a Linux host provides through its libicu packages.

The global tool remains a temporary technical-preview distribution.

• docs/bedrock-spec-v1.md: the normative Bedrock file-format spec.
• docs/engineering-principles.md: engineering invariants the code must satisfy.
• docs/writing-principles.md: how this repository writes documents and comments.
• docs/decisions.md: architectural decision log, with rationale.
• docs/roadmap.md: milestones M0–M9 and the deferred backlog.
• docs/benchmarks.md: the M8 measurement record (what is measured, on what hardware, under what rules, and what has not been measured).
• eng/README.md: the build, test, packaging, smoke, and authored-text integrity commands.
• docs/lineage.md: what the predecessors (v2, the PhD thesis, the SPARQL2FCA prototype) settled, distilled.
• AGENTS.md: repo orientation for contributors and coding agents (CLAUDE.md is its Claude Code import shim).

vNext's golden tests compare output byte-for-byte against fixtures produced by FcaBedrock v2, under fixtures/v2/. Fixture-level dataset provenance and attribution are documented in fixtures/v2/ATTRIBUTION.md.

This project is a from-scratch successor to the original FcaBedrock (v2, VB.NET). Initial versions of FcaBedrock were created as part of the author's BSc Computing final year project, and subsequent versions were developed during the author's PhD at Sheffield Hallam University on appropriating structured data for Formal Concept Analysis (FCA).

The original FcaBedrock tool was published as:

Andrews, S., Orphanides, C.: FcaBedrock, a Formal Context Creator. In: Croitoru, M., Ferré, S., Lukose, D. (eds.) ICCS 2010. LNCS, vol. 6208, pp. 181–184. Springer, Heidelberg (2010).

The ICCS 2010 paper is the primary publication reference for the original tool. The later PhD thesis provides the fuller treatment of FCA data appropriation and the conceptual-scaling semantics that inform vNext.

The original tool remains available on SourceForge. vNext is a sole-authored rewrite that reproduces the v2 compatibility behaviour (verified against the v2 output as byte-equality golden tests) while modernising the architecture. The SPARQL2FCA prototype informs the deferred triple-store source path.

MIT: see LICENSE. (Same license as FcaBedrock v2.)

Copyright © Constantinos Orphanides.