v1.0 readiness report

This is the outcome-based v1.0 decision required by the project design. It records evidence current through 2026-08-08. Performance measurements used Ruby 4.0.0 on arm64-darwin24. Passing the implementation checklist is not sufficient for a stable release.

Decision

HOLD v1.0. Compatibility behavior, scale construction, semantic-value signatures, and the repository compatibility suite have evidence. The exact formal public performance rerun is now recorded for the measured revision below. The published ten-case error comparison has not received independent third-party review. Its machine-readable R001 status is HOLD / awaiting_independent_review; the linked status leads to the complete rubric, closed record schema, immutable evidence identity, and imported-record registry.

R001: HOLD — awaiting_independent_review. <!-- r001-review-status:end -->

Feature development is not frozen. The open release gate blocks publication of v1.0, not feature development. New work remains subject to the feature budgets, maturity rules, compatibility checks, and exact-revision release gates documented by the project. The current Grammar IR and Automaton IR contracts remain closed and validated; before v1.0, incompatible changes are coordinated with their writers, readers, schemas, fixtures, and downstream consumers.

The format-v6 batch Red/Green CST has been selected as part of the initial Stable v1 API. Its syntax-only incremental layer remains Experimental. Other Preview and Experimental features may continue to ship in prereleases without promotion; before v1.0, those surfaces can change between prereleases when the release notes, migration note, regressions, and maturity evidence are updated. The release lock applies to Stable declarations and versioned persisted contracts, not to every Preview implementation detail or evidence capture.

KPI result

Public-gem migration evidence

Only public grammar files, public commands, and observable test results were used. Neither racc implementation files nor generated source were inspected. Each repository was cloned at the recorded revision:

Namae generated and ran as one embedded file. The other two grammars contain a user header whose superclass is named Racc::Parser. Their PoCs preload this explicit migration adapter before loading the generated parser:

require "ibex/runtime"

module Racc
  Parser = Ibex::Runtime::Parser
end

This is the adapter recommended by ibex migrate-check; it does not load or execute the racc runtime. The PoCs uncovered and fixed three compatibility gaps: an omitted end before a user-code section, an application initializer that omits super plus historical value-stack reads, and an unqualified ParseError.

Formal Pure Ruby performance comparison

At clean Ibex revision 984d4ae7a1c96db4c71e3077669842b7bbc3b4ea, the readiness projection for three pinned workloads on Ruby 4.0.0, arm64-darwin24, with YJIT disabled records slower cold generation and new-instance runtime than Racc 1.8.1's Ruby backend; the direct formal result artifact is absent, so this is evidence-pending and non-publishable as a comparative claim.

Evidence record ID: racc-public-performance-2026-07-31. Its complete scope, evidence paths, missing artifact, and limitations are registered in claims.yml under the comparison policy. CPU model, kernel release, and processor count were not retained in this readiness projection. Host CPU and host OS were also not recorded as separate fields. The measurements below do not describe the current checkout.

The historical readiness projection says the measurement was collected on 2026-07-31 from clean revision 984d4ae7a1c96db4c71e3077669842b7bbc3b4ea with ten alternating isolated runs per implementation, 50 warm-up workloads, 250 measured workloads, and 10,000 bootstrap samples. Each workload parses the five fixed public inputs. Ruby 4.0.0 ran with YJIT disabled; Racc 1.8.1 was forced to its Ruby backend and every worker verified the selected runtime. Ratios below are Ibex divided by Racc; time cells include the bootstrap 95% interval. The harness's target_met field marks absolute parity when the interval's upper bound is no greater than 1.0. That field is diagnostic: v1.0 requires publication of measurements and their conditions, while a future performance gate may reject only a relative regression measured under an identical environment and configuration.

Result values and ordered result sequences are equivalent in every runtime row. The measured parser-time medians in milliseconds per parse were 0.039443/0.040048 (Ibex/Racc) for Namae reuse, 0.020925/0.019897 for BCDice reuse, and 0.024892/0.025280 for Nokogiri reuse. The corresponding new-instance medians were 0.048234/0.040413, 0.027523/0.020044, and 0.030420/0.025642.

The results deliberately retain the unfavorable rows: cold generation is 23.8–32.9% slower, and new-instance parsing is 18.6–37.3% slower. Reuse point estimates range from 1.5% faster to 5.2% slower. Ibex allocates fewer objects for every reuse workload, while new-instance allocation ratios remain 1.051–1.190x. Generated output is smaller for all three grammars. These values are a release baseline, not portable scores or an assertion of parity. <!-- comparative-evidence:racc-public-performance-2026-07-31:end -->

Exact-revision formal rerun

At clean Ibex revision 26e94ce631bf5c075ecbca0205a34a8c231c31d9, on Ruby 4.0.0, arm64-darwin24, with YJIT disabled, the direct formal comparison of the pinned Namae, BCDice command, and Nokogiri CSS workloads against Racc 1.8.1 produced equivalent result sequences; Ibex recorded slower cold generation and new-instance parsing, fewer reuse allocations, and smaller generated output in every workload.

The complete formal result is 2026-08-08-8c9cef999d09-ruby-4.0.0-arm64-darwin24.json. It records ten alternating isolated runs per implementation and scenario, 50 warm-up workloads, 250 measured workloads, five behavior probes, 10,000 bootstrap samples, exact public checkout revisions, and equivalent result and result-sequence digests. <!-- comparative-claim:racc-public-performance-2026-08-08:end -->

Scale evidence

Run:

benchmark/scale.rb --rules 500 --iterations 3

The reproducible synthetic chain shares its grammar shape with the 500-rule black-box compatibility test. The measured report contains 501 productions, 503 direct-LALR construction states, 503 final states, no conflicts, and 41,332 bytes of compact generated Ruby. Three complete parse-to-codegen builds averaged 125.008 ms with a 122.742–127.002 ms range. The Automaton IR digest was fe0e2f0c9bf16e7aa22a7ebcea40b229fedbb573f83af37596b76e0b989c3338.

This synthetic result establishes the requested scale bound. The 139-production representative grammar remains the realistic workload, so neither result is presented as a substitute for an application-specific benchmark.

Error UX and type evidence

error-ux.md and its versioned JSON publish the same ten malformed JSON inputs against the public racc callback. Eight selected repairs were assessed useful. A maintainer assessment is not independent review; at least one external reviewer must record a review of the cases and usefulness labels before this KPI passes. Reviewers use the versioned independent rubric, generate a draft with the exact checkout and environment identity, set all structured consent fields, and publish the final permalink-free payload at a full-SHA blob URL. Maintainers import the exact bytes and register publication provenance separately, without rewriting. Ordinary CI validates the offline kit; the release gate performs fail-closed blob checks and requires the source owner, GitHub API author, publisher, and reviewer logins to agree. This establishes only GitHub namespace control and account metadata, not cryptographic identity or a signature. The gate remains intentionally failing while the public status is HOLD.

The 2026-07-31 evidence snapshot recorded 23,517 typed calls and 2,946 untyped calls out of 26,463, or 88.9% typed. Generated parser RBS refines declared terminal, nonterminal, RHS tuple, and reduction result types. Untyped values remain explicit at undeclared grammar symbols, decoded JSON, dynamic table cells, and opaque application Ruby boundaries. The current repository result is maintained in the generated type-statistics block in README.md.

Release-basis evidence

bundle exec rake release:reproducible compares 47 normalized Stable RBS declaration files with the v0.2.0 baseline. The current result has zero differences; the installed-Gem embedded-source helper is an internal packaging implementation and is outside that public lock. The task also builds both gems twice under distinct locale, timezone, and frozen-string settings and requires byte-identical artifacts. SHA-256 digests are emitted for the exact candidate revision rather than recorded as if the current HOLD revision were a release.

No release signing credential is stored in this repository. A signature or provenance attestation must be supplied by a protected external release environment after the outcome gates pass; an unsigned local test key would not establish publisher identity.

Actions required to release v1.0

1. Obtain and publish an independent review of the ten error cases using the

R001 rubric, then import the record byte-for-byte with its immutable permalink and consent. Preserve disagreements separately from the normative maintainer assessment.

1. Re-run every compatibility, IR, type, benchmark, and site gate on the exact

release revision.