AILang/docs/journals/2026-05-12-iter-ext-rename.md

iter ext-rename — .ailx extension renamed to .ail across the live toolchain

Date: 2026-05-12 Started from: 17b370b (post-audit-ms close, working tree clean) Status: DONE Tasks completed: 1 of 1

Summary

The surface-form file extension changes from .ailx to .ail. AILang's authoring surface now uses the same .ail stem as its canonical JSON form (.ail.json), giving the language a single coherent extension family: .ail is the LLM-authored Form A; .ail.json is the canonical JSON-AST Form B that ail check / build / run actually loads today.

The earlier .ailx extension carried an unmotivated x. The cross-model authoring-form test (cma + ms milestones, closed earlier today) treated .ailx purely as a cohort identifier; once the empirical case for keeping a separate authoring surface had been ratified (DESIGN.md §Decision-6 addendum), the awkward extension was the last asymmetry between Form A and Form B. User-initiated rename.

Scope

In scope (touched):

• 61 example files examples/**/*.ailx → .ail (57 top-level + 4 examples/fieldtest/) renamed via git mv.
• experiments/.../rendered/ailx.md → ail.md rename.
• All live toolchain prose and code: crates/ail/, crates/ailang-surface/, crates/ailang-core/specs/form_a.md, docs/DESIGN.md, docs/roadmap.md, docs/PROSE_ROUNDTRIP.md, bench/reference/*.c, all of skills/, the Cross-Model Authoring experiment crates under experiments/.../{render,harness,master,rendered,README.md}.
• Cohort identifier ailx → ail in the experiment crate (Rust Cohort::Ailx → Cohort::Ail, Form::Ailx → Form::Ail, per-cohort path component, {form-only: ailx} marker,

Out of scope (untouched, by design):

• docs/journal-archive.md (content-frozen per CLAUDE.md).
• All docs/journals/, docs/specs/, docs/plans/, bench/orchestrator-stats/ — historical records describing states as they were.
• experiments/.../runs/ — frozen LLM-output artefacts; the models in those runs actually saw .ailx, and renaming the artefacts would falsify the experimental record.

The exclusion preserves the journals as honest history. Anyone chasing why a 2026-05-11 fieldtest names .ailx files will find that the renaming happened today and that the names were correct at the time of writing.

Why boss-direct edit (no planner / implement dispatch)

Same rationale as iter rt.2: the user fully specified the transformation (rename .ailx → .ail, rename cohort ailx → ail, historical records untouched), down to the three open questions that were resolved up-front via AskUserQuestion (cohort name; treatment of frozen runs; treatment of historical docs). The execution was two git mv passes plus one heavily-scoped sed over an explicit 41-file whitelist (plus two follow-up files surfaced by the negative-grep). No design judgement deferred to execution time.

Files touched (working-tree counts)

• 61 renames under examples/.
• 1 rename experiments/.../rendered/ailx.md → ail.md.
• 35 content-edited files: the 41-file SCOPE whitelist minus the experiment-crate files that had no ailx content, plus two follow-up files surfaced by the negative-grep (examples/bench_list_sum_explicit.ail's in-source comment; experiments/.../rendered/json.md for three AILX acronyms in prose).

Verification

• cargo build --workspace clean.
• cargo test --workspace green; the renamed identifiers every_ail_fixture_matches_its_json_counterpart and parse_then_print_then_parse_is_idempotent_on_every_ail_fixture in crates/ailang-surface/tests/round_trip.rs were run explicitly and pass.
• Experiment crate cargo test (out-of-workspace) green.
• bench/check.py, bench/compile_check.py, bench/cross_lang.py: 0 regressed across all three; 6 improved-beyond-tolerance on latency.explicit_at_rc (same cluster the previous two audits today already observed; decoupled from this rename — baseline left pristine).
• Negative grep: git grep -nIi 'ailx|Ailx|AILX' outside the out-of-scope paths returns no matches.

Roadmap implications

The .ail extension is now canonical authoring surface but the CLI does not yet accept it — ail check foo.ail still produces the misleading JSON-parse error. The existing P2 todo "ail check/build/run accept .ail extension" (roadmap.md line 185) is the natural next iteration: it closes the loop opened by today's rename and removes the largest first-command friction for any LLM-author writing in Form A. Promoting that todo to the immediate next dispatch.