Resolves Gitea #12 — the design fork from the 2026-05-20 /boss
session, surfaced independently by two prior fieldtests
(mut-local F3 + loop-recur `run_forever`).
Mechanics, layer by layer:
Parser — `crates/ailang-surface/src/parse.rs:1322-1331` drops
the 4-line `expected at least one argument` guard in
`parse_app_body`. Grammar comments at file top change `term+`
to `term*` on both `app-term` and `tail-app-term`; doc comment
on `parse_app_body` changes `1+ args` to `0+ args`. Inline
comment cites #12 and notes which layers below already accept
empty args.
Serde — `crates/ailang-core/src/ast.rs:419-425` annotates
`Term::App.args` with `#[serde(default)]`, mirroring
`Term::Ctor.args`'s *actual* attrs verbatim (no
`skip_serializing_if`). Write behaviour unchanged — canonical
JSON still emits `"args":[]` for nullary calls; only read
behaviour gains tolerance for the `args` key being absent.
Verified hash-impact-free at plan time:
`grep -rn '"args":\[\]' examples/*.ail.json` returns zero
matches, so no existing fixture's canonical bytes shift.
Doc-honesty — `design/contracts/data-model.md`:
(a) the `app` jsonc shape gains an explicit "args may be
empty / read-tolerant" note;
(b) the existing `ctor` comment claiming "args omitted when
empty" was factually false (Ctor.args has no
`skip_serializing_if`; a serde probe at plan time
confirmed writes always emit `"args":[]`). Rewritten to
describe the actual write/read asymmetry, with a
cross-reference to the new `app` note.
E2E pin — `crates/ail/tests/nullary_app_e2e.rs` +
`examples/nullary_app_smoke.ail`. Defines `greet : fn()
-> Unit !IO` and calls it as `(app greet)`; asserts stdout
`"hello\n"`. RED→GREEN pin for the parser change AND the
milestone-protecting E2E for nullary call surface going
forward. Fixture literal is `"hello"` (no `\n`) because
`io/print_str` lowers via `puts` which appends a newline —
the plan body had a `"hello\n"` literal which would have
yielded `"hello\n\n"`; the implementer caught and aligned to
the canonical pattern in `examples/hello.ail` while writing
the fixture, fix scoped to that single file.
Layers below parser untouched: typechecker's arity check at
`crates/ailang-check/src/lib.rs:3300` is `args.len() !=
params.len()` which is `0 != 0 → false` for nullary; codegen's
`args.iter().zip(sig.params.iter())` at
`crates/ailang-codegen/src/lib.rs:2410` is an empty loop;
LLVM `call @ail_<mod>_<name>()` with empty arglist is valid;
surface printer's arg-emit loop at
`crates/ailang-surface/src/print.rs:430-434` writes nothing for
empty args, producing exactly `(app f)`.
Verification: full workspace `cargo test --workspace --quiet`
green (0 failed across all crates); drift pins
`design_index_pin 5/5` + `design_schema_drift 8/8`; round-trip
`2/2`; new `nullary_app_e2e 1/1`. Stats file:
`bench/orchestrator-stats/2026-05-20-iter-nullary-app.1.json`.
closes#12
A re-grep found 15 live references (excluding docs/specs/ and
docs/plans/, which stay historical) the previous two commits
missed — all in source comments, doctests, bench helpers, and one
agent file.
Per-file:
- crates/ail/src/main.rs: typeclass-coherence diagnostic comment
pointed at "the JOURNAL queue's wording" — points at
design/contracts/typeclasses.md alone.
- crates/ailang-prose/src/lib.rs: `//!` header referred to
docs/JOURNAL.md "Pinned: human-readable prose surface" —
retargeted to design/contracts/authoring-surface.md.
- crates/ailang-check/src/lib.rs: bugfix tag + "see iter
method-dispatch-refactor journal" prose collapsed to a clean
rationale paragraph; the canonical shape is stated inline.
- crates/ailang-surface/tests/prelude_decouple_carve_out_pin.rs:
"(d) record the rationale in a per-iter journal" →
"(d) record the rationale in the commit body".
- crates/ailang-surface/tests/prelude_module_hash_pin.rs: header
collapsed (pd.2/pd.3 milestone narrative dropped — the test's
purpose is self-evident from its body); both "per-iter journal"
drift-instructions point at the commit body.
- runtime/rc.c: "bench numbers in JOURNAL 18f.2" →
"original profiling bench numbers".
- bench/run.sh: two "JOURNAL entry" comments → "commit body".
- bench/architect_sweeps.sh: header rewritten (cross-ref to the
design-md-consolidation milestone commits, not a JOURNAL entry).
Sweep-4 extended with two new anti-regrowth phrases
("see the per-iter journal", "in a per-iter journal") so journal
prose can't grow back into design/contracts/ silently.
- skills/audit/agents/ailang-architect.md: "unlike a journal it
lives on main" → "since it lives on main".
- ail-embed/src/bin/timeshard_runner.rs: "records it in the
close-out journal" → "prints it to stderr".
- ail-embed/tests/timeshard.rs: two "journal-only friction timing"
→ "stderr-only friction timing".
Verification (after the edit):
- `grep -rin '\bjournal\b'` against live tree returns exactly two
hits: the Sweep-4 regex itself (intentional — TABU phrases that
prevent regrowth) and the PHRASES array in design_index_pin.rs
(intentional — the same regrowth guard at test level). Both are
load-bearing negative assertions.
- `bash bench/architect_sweeps.sh` exits 0 ("All five sweeps
clean") — no design/-side regrowth.
- `cargo build --workspace` green; `cargo test --workspace` green.
Strict application of the "Future-Use, not Verlauf" criterion to the
two remaining journal artefacts:
- `docs/journals/` (110 files): the per-iter and audit journals from
2026-05-11 onward. Pure history; no live reader after the previous
sweep. Entire directory removed.
- `docs/journals/2026-05-19-design-decision-records.md`: the one file
that had live readers (`docs_honesty_pin.rs:108`, `parse.rs:80`,
`duplicate_ctor_pin.rs:8`, three roadmap.md mentions) and was framed
as a "relitigation guard". On re-examination its three asserted
pinned phrases ("Regions were considered and rejected", the
"demands annotations *because*" rationale, the prose-render
placeholder statement) are rationale-prose, not load-bearing
invariants — the test pinned itself, not a system property. Any
Decision that still holds lives in the code, `design/contracts/`,
or `design/models/`. Removed with the rest.
- `docs/journal-archive.md` (pre-2026-05-11 history): content-frozen
long-tail history with no live reader. Removed; if anyone ever
needs the pre-cutoff rationale they can `git log --before=2026-05-11
--grep=<keyword>`.
Live-file consequences:
- `docs_honesty_pin.rs` `design_md_present_tense_anchors_present`:
the three `records.*` assertions and the `read("docs/journals/…")`
are dropped; the contract/model anchor pins remain.
- `duplicate_ctor_pin.rs`: the "why-two-overlays rationale lives in
docs/journals/…" comment is replaced with the rationale inline.
- `parse.rs`: the "form-refinement rationale lives in docs/journals/…"
comment is dropped (the rule body already states the refinement).
- `roadmap.md`: the decision-records mention in the DESIGN.md →
design/ entry's body is dropped; the journal-archive.md `context:`
pointers across ~12 closed entries are either rephrased to point
at the relevant iter/audit (no path), or simplified to a one-line
comment when the iter name alone carries the story.
- `CLAUDE.md` Roles section: the `docs/journal-archive.md` slot is
removed; vocabulary note rephrased.
- `design/INDEX.md`: the Docs bullet drops `journal-archive.md`.
- `skills/README.md` bootstrap-rationale pointer rephrased.
`docs/specs/` and `docs/plans/` (per-milestone specs and per-iteration
plans) are unaffected — they remain the structured-design artefacts
they were before this sweep.
Workspace builds, full test suite green.
Follow-up to bcd4181: the remaining ~530 inline `//` and `///`
comments still carrying opaque shorthand are now reformulated to
their content phrases. The only surviving `iter-<code>` reference
in source is the literal filename
`docs/journals/2026-05-13-iter-mq.3.md` (a real journal file).
Sweep covered:
- `// Iter X.Y: <text>` prefixes (Iter 13a / 14a / 14e / 15g-aux /
16b.x / 16d / 16e / 18b / 18c.x / 18d.x / 18e / 18g.x / 19a /
19a.1 / 19b / 20a / 20f / 22-floats.x / 22b.x / 22c / 23.x /
24.1 / cli-diag-human / hs.x / str-concat / etc.) — fully
removed; the descriptive text that followed each prefix stays.
- `// (Decision N)` and `per Decision N` and `Decision N axis 3` —
replaced with the content phrase plus the relevant contract
file (`design/contracts/tail-calls.md` for Decision 8,
`design/contracts/memory-model.md` for Decision 10,
`design/contracts/typeclasses.md` and `design/models/typeclasses.md`
for Decision 11, `design/contracts/authoring-surface.md` for
Decision 6, "the transitional dual-allocator" for Decision 9,
"Effect prose" for Decision 3).
- `// mq.X / mq.X (Task N) / mq.X journal / mq.X invariant` ->
"the canonical-class-form rule / Class-class repurpose /
method-dispatch-refactor journal / canonical-class-form
invariant".
- `// ct.X / ct.X (canonical-type-names) / ct.1.5a + ctt.2 /
ct.2 Task N` -> "the canonical-form rule for type references /
the canonical-form normalisation step / canonical-type-lookup
refactor".
- `// eob.X` -> "heap-Str-ABI" / "the Str carve-out".
- `// rpe.X` -> "the per-type-print-op retirement".
- `// post-mq.X / Pre-ct.X / pre-mq.X` -> "post-canonical-class-form" /
"Pre-canonical-type-form" etc.
- `/// Iter X regression: / /// Iter X.Y: / /// Iter A arm-close /
/// Iter ct.4 (...): / /// Iter rpe.1 ...` -> descriptive
phrases.
The journal filename in `crates/ailang-core/src/workspace.rs:573`
stays verbatim because it points at an actual file under
`docs/journals/`.
Tests: full `cargo test --workspace` green (80/80 test-result blocks
clean, no FAILED line). design_index_pin 5/5 + docs_honesty_pin 5/5
gating tests pass.
The 3020-line docs/DESIGN.md is replaced by the design/ ledger:
design/INDEX.md (sole addressable spine, typed Contracts+Models tables,
polymorphic links — prose file OR authoritative source //!), 14
design/contracts/*.md test-linked invariants + 3 source-link-only
contracts (mangling/env-construction/qualified-xref, no prose file —
code is SoT), 5 design/models/*.md whitepapers, and
docs/journals/2026-05-19-design-decision-records.md (the
relitigation-guard archive — every why/rejected/does-not-do/rollback/
empirical ### moved out at ###-granularity). Clean cut: git rm
docs/DESIGN.md, no stub.
RED-first crates/ailang-core/tests/design_index_pin.rs — the 4-clause
anti-regrowth spine (DESIGN.md-gone / every-INDEX-link-resolves /
every-contract-names-a-resolvable-ratifier /
contracts-carry-no-decision-record-prose) — demonstrably RED before,
GREEN after. Build-atomic by task ordering: design_schema_drift.rs's
include_str! (the only compile-time consumer) retargeted to
design/contracts/data-model.md BEFORE the deletion; its
## Data model/## Pipeline slicer dropped (a simplification the split
enables). 2 NoInstance diagnostics + 2 lockstep E2Es retargeted to
design/contracts/{float-semantics,typeclasses}.md. ~12 agent reading
lists + 5 SKILL bodies + CLAUDE.md + skills/README.md + ~25
code/C/.ail/spec comment xrefs retargeted; OQ7 dangling 'Iter 13b'
cite deleted (no forward target — a pointer would be fiction).
honesty-rule.md rewritten so the rule names the new home
(rationale->journals), resolving the recon-found internal
contradiction; the two docs_honesty_pin.rs:70,72 pinned phrases kept
verbatim+contiguous.
Boss-verified independently: cargo test --workspace 646 passed /
0 failed; design_index_pin 4/4; acceptance grep CLEAN of live
DESIGN.md refs (residuals = only the spec-mandated clause-4
deletion-enforcer). 2 DONE_WITH_CONCERNS routed to the mandatory
milestone-close audit: (a) str-abi.md:23 '(iter str-concat,
2026-05-13)' provenance stamp trips advisory architect_sweeps Sweep-1
— Boss-confirmed byte-identical to DESIGN.md@deeffb1:2062-2065, a
faithfully-migrated PRE-EXISTING anchor (regexes verbatim, only path
retargeted), NOT split-introduced — RATIFY-or-tidy at audit; (b) a
now stale-direction intra-prose 'see Str ABI below' cross-ref in
float-semantics.md — audit-adjudication candidate. Plan defect noted:
Task 9 Step 4's verbatim acceptance grep used a ^./ anchor not
matching the system's grep -rIn output; substance re-verified CLEAN.
Spec grounding-check PASS x2. Journals INDEX + decision-records
pointer appended (Boss-only).
Tasks 1-3 of docs/plans/embedding-abi-m1.1.md, a verified known-good
subset (cargo build --workspace exit 0; full workspace green; the
roundtrip_cli all-examples gate green):
- Task 1: CLI build-path MissingEntryMain baseline pin
(examples/embed_noentry_baseline.ail + embed_missing_main_baseline.rs;
triple-assertion, layered on the green codegen-unit pin lib.rs:3314).
- Task 2: additive FnDef.export: Option<String> (serde default +
skip_serializing_if, modelled on FnDef.doc); compile-driven thread
of export: None across ~85 FnDef/AstFnDef literals / 18 files incl.
all in-source #[cfg(test)] mod tests + drift/hash/spec-drift
literals + the codegen lib.rs:3320 in-source pin; hash-stability
golden pin; DESIGN.md fn-JSON "export" line. DONE_WITH_CONCERNS
(plan symbol content_hash_fn -> def_hash per hash_pin.rs, plan-
pseudo-vs-reality class, plan corrected).
- Task 3: Form-A (export "<sym>") modifier — parse_export +
parse_fn thread + write_fn_def emission + form_a.md grammar;
byte-identical round-trip.
Task 4 BLOCKED (Boss plan-defect: fixtures declared module != file
stem; AILang's loader hard-enforces module==stem at workspace.rs:438,
so ail check panicked on load before the gate). Boss resolution
(Option 2, overriding the orchestrator's Option 1, rationale in the
journal + plan Design-decision 6): keep descriptive embed_* filenames,
rename fixture MODULES to their stems — the C symbol backtest_step
stays via (export ...), demonstrating spec Decision 2's mangling-
decoupling rather than violating it; archive becomes
libembed_backtest_step.a, internal symbol @ail_embed_backtest_step_step,
host.c unchanged. Plan fixed (Design-decision 6 + Task-4 module==stem
+ Task-5/6/7 dependent strings + the no-*. Float-head + content_hash_fn
concerns folded). Headline fixture corrected; blocked-Task-4 WIP
discarded (recreated by the [4,7] re-dispatch from the fixed plan).
PARTIAL commit (not the iter's final commit): the implement Repair
path mandates committing the known-good subset so the [4,7]
re-dispatch starts from a clean tree that includes Tasks 1-3 (Tasks
4-7 structurally depend on the schema field + surface). INDEX line
added when the full iter lands post-re-dispatch.
mut/var/assign removed from AILang entirely and atomically. Deleted:
Term::Mut/Term::Assign/struct MutVar; the three Form-A keywords +
parse_mut/parse_assign + grammar EBNF; the 4 mut CheckError variants;
the mut_scope_stack synth threading (param dropped from synth + every
internal/external/test caller); the two lower_term arms; and every
exhaustive no-_ Term::Mut/Term::Assign match arm across 17 source
files — cut in lockstep with DESIGN.md, fixtures, the drift trio,
carve-out and roadmap so the schema is honest at every commit. No
catch-all wildcard introduced (verified). loop/recur + let/if are
the surviving forms.
The shared codegen alloca machinery survives (loop reuses it):
mut_var_allocas renamed binder_allocas (representation-only, loop
codegen byte-identical) and the shared Term::Lam escape guard
simplified to !loop_stack.is_empty() with the loop half
(LoopBinderCapturedByLambda) byte-equivalent. Feature-acceptance
applied inverted: the removed feature fails clause 2 (redundant)
and clause 3 (IS the iterated-mutable-state bug class).
Behaviour preservation is executable: mut_counter/mut_sum_floats
still print 55 after the faithful let/if rewrite. The removal is
made executable by the new mut_removed_pin.rs (4 must-fail pins).
Independent verification: cargo test --workspace 605/0, zero
residual mut symbols in any crate source, loop/recur non-regression
all green (55 / 500000500000 / infinite-compiles / the
lambda_capturing_loop_binder pin), roundtrip_cli PASS.
One DONE_WITH_CONCERNS: a 4th recurrence of the recon-undercount
class (in-source mod tests + a drift-pin fn + 5 orphaned mut
.ail.json carve-outs + a non-enumerated E0599); all resolved within
implementer remit, no behaviour change. Milestone-close audit then
fieldtest remain.
spec docs/specs/2026-05-18-remove-mut-var-assign.md (grounding PASS)
plan docs/plans/remove-mut-var-assign.1.md
First of three iterations of the standalone loop/recur milestone
(spec 97c1ed1). loop/recur become real parseable / printable /
round-trippable / hash-stable strictly-additive AST nodes across
every no-wildcard exhaustive Term match in all six crates, plus
parse/print, prose arms, DESIGN.md + form_a.md schema blocks,
drift/coverage/hash anchors, and the spec's worked sum_to program
as a green round-trip fixture. NO typecheck semantics and NO real
codegen this iter by design: synth and lower_term are stubbed
CheckError::Internal / CodegenError::Internal exactly as mut.1
(real typecheck = iter 2, real loop-header/phi/back-edge = iter 3).
Two binding Boss design calls recorded in the plan header and the
journal: (1) verify_tail_positions "byte-unchanged" = its tail-app
verification role is unchanged, not its source — it is an
exhaustive no-wildcard match so two descent-only arms are
mandatory; acceptance evidence is the tail-app non-regression test.
(2) codegen is in iter-1 scope as stubs/pass-throughs because the
workspace must compile for cargo test --workspace.
Three plan-pseudo-vs-reality substitutions (serde Type::Con
literal, bare Int -> (con Int), unqualified LoopBinder) and one
recon-undercount integration-test site, all intent-preserving and
journalled. Boss forward-fix folded in: the committed specs
themselves wrote bare Int in the loop-binder snippets (parses as
Type::Var) — corrected the three headline snippets to (con Int) for
doc-honesty (no design/schema change).
cargo test --workspace 600 -> 608 / 0 red (Boss-reran
independently); iter13a + new loop_recur hash pins green.
One forward iteration; main never rewound. 1ff7e81 (the pre-9973546
commit) is the per-region byte oracle — every reverted source/test
file is byte-identical to it; crates/ailang-check/src/lib.rs fully so.
Root cause being corrected: the Iteration-discipline milestone was an
over-escalation of fieldtest finding F1 (a [friction] item whose own
minimal recommendation was a DESIGN.md note). Its totality dichotomy
made the maximally-LLM-natural build(d:Int)=Node(1,build(d-1),
build(d-1)) inexpressible (it.3 BLOCKED); the only in-thesis escape
(A1/it.2b) conceded the language's first documented-unenforced
totality precondition — a purity-pillar dilution the user rejected in
favour of a full revert + rebuild.
Removed: Term::Loop/Term::Recur/LoopBinder; the verify_structural_
recursion guardedness pass + term_contains_loop + Diverge-injection +
the transitively-it.2 module_fns plumbing; the five Recur*/
NonStructuralRecursion CheckError variants (+ code() + the 3 dedicated
ctx() arms); the it.1 codegen loop-header/phi/back-edge + parallel
block_terminated setter; all Loop/Recur walker arms; 16 it.1/it.2
fixtures; 2 pin files; bench/it3-oracle/. Restored: 2 RC fixtures to
1ff7e81 content.
Surgically kept (not in 1ff7e81, landed with the milestone but
independently sound): feature-acceptance clause 3 in DESIGN.md and
skills/brainstorm/SKILL.md, with its worked example de-claimed from
"shipped" to hypothetical-illustration form; the F3 P2 todo.
bench/orchestrator-stats/2026-05-15-iter-it.{1,2,3}.json kept as
historical record (like journals/plans).
Sole net addition: an honest F1/F4 documented-idiom note in DESIGN.md
(the tail-recursive accumulator fallback; examples/mut_counter.ail),
guarded by a doc-presence test — "a documentation note is not a
reshape", asserts nothing at the typecheck level.
Roadmap: the Iteration-discipline block + blocking-fork section
removed; the genuine total-Int-recursion ambition preserved as a
deferred P2 milestone sequenced behind a future Nat/refinement-types
milestone (not abandoned — correctly sequenced after the type
machinery it needs). 2026-05-15-iteration-discipline.md carries a
superseded header; it.1/it.2/it.3 journals + plans stay as history.
Correctness gate PRISTINE: 164 surviving 1ff7e81-era fixtures
ail check/ail run byte-identical to pre-milestone behaviour (verified
against a 1ff7e81 worktree reference compiler, zero drift);
cargo test --workspace 600/0; zero residual it.1/it.2 production
surface.
Spec docs/specs/2026-05-16-iteration-discipline-revert.md (b3853bf),
plan docs/plans/2026-05-16-iter-revert.md (abf0013).
Iteration-discipline milestone, 1 of 3. Adds named loop + recur as
strictly-additive first-class AST nodes: parse/print/prose/serde/
round-trip/schema lockstep, typecheck (binder typing + recur
arity/type unification via loop_stack threaded as mut.2's
mut_scope_stack; recur-tail-position via verify_loop_body), codegen
(loop-header + one phi per binder; recur back-edge br with a NEW
parallel block_terminated setter; lambda-boundary loop_frames
save/restore). Four Recur* CheckError variants. Strictly additive:
zero deletions touch tail-app/tail-do or the seven existing
block_terminated sites — this is what makes the destructive it.3
safe. recur synth = fresh metavar (resolves the plan's flagged
Type::unit() risk). loop_counter->55, loop_in_lambda->49, four
negatives fire, tail-app byte-identical, cargo test --workspace
green. Spec fda9b78, plan 7381a42.
First iteration of the mut-local milestone (foundation step on the
Stateful-islands roadmap path). Lands the schema + surface tier:
Term::Mut, Term::Assign, and the nested MutVar struct become
first-class AST nodes that round-trip cleanly through Form A.
Typecheck and codegen recognition are deferred to mut.2 and mut.3
per the spec's out-of-iteration boundary; reaching either dispatch
entry point with these variants produces CheckError::Internal /
CodegenError::Internal with a 'deferred to iter mut.{2,3}' message.
Concretely:
- crates/ailang-core/src/ast.rs: two new Term variants behind
#[serde(tag = 't')]; pub struct MutVar { name, ty, init } adjacent
to Arm. Two canonical-bytes pin tests for the explicit-empty-vars
serialisation and the assign round-trip.
- ~25 substantive Term-walker arms across ailang-core/desugar,
ailang-core/workspace, ailang-check (lib + lift + linearity + mono
+ pre_desugar_validation + reuse_shape + uniqueness),
ailang-codegen (escape + lambda + lib), ailang-prose, and
crates/ail/src/main.rs. Universal policy: substantive recurse-into-
children at every site; only the two dispatch entry points
(synth in ailang-check, lower_term in ailang-codegen) stub with
Internal-error. One test-side walker arm in
crates/ail/tests/codegen_import_map_fallback_pin.rs not
enumerated by the plan was added as well (defensive recursion).
- ailang-surface: parse_mut + parse_assign helpers; Term::Mut
body desugared from a flat statement sequence into a right-folded
Term::Seq chain inside the JSON-AST. Print arms in print.rs match
the parser convention. EBNF prologue + crates/ailang-core/specs/
form_a.md productions updated. Four new parser pin tests cover
the empty-mut, single-var, body-required, and vars-only-no-body
cases.
- Drift + coverage tests extended: design_schema_drift.rs adds two
exemplars + match arms; schema_coverage.rs adds two VariantTag
entries + EXPECTED_VARIANTS + visit_term arms; spec_drift.rs adds
two exemplars + match arms. DESIGN.md §'Term (expression)' gets
jsonc-blocked schemas for the two new variants.
- examples/mut.ail: six-fn round-trip fixture exercising empty mut,
single-var, two-var, nested-shadow, and the four supported scalar
return types (Int, Float, Bool, Unit). The round_trip auto-glob
and schema_coverage corpus walker both pick it up.
Plan deviation: the plan named lib.rs:2572 as the typecheck
dispatch stub site, but that line is actually verify_tail_positions
(substantive walker). The real dispatch is synth (3403-area, stub
at 3489); the orchestrator routed correctly.
Tests: 564 → 579 green; cargo build green; round-trip green for
the new fixture; all drift + coverage tests green.
Journal: docs/journals/2026-05-15-iter-mut.1.md.
Refs: docs/specs/2026-05-15-mut-local.md, docs/plans/2026-05-15-iter-mut.1.md.
Deleted examples/prelude.ail.json (-559 lines). The cross-form-identity
preflight test that ratified pd.3's load-bearing assumption at module
hash 3abe0d3fa3c11c99 has discharged its purpose and was removed
along with its supporting bytes; the long-term prelude_parse_yields_canonical_hash
anchor stays. The ail-CLI migrate-bare-cross-module-refs subcommand's
defensive include + lockstep skip-branch removed; the rewrite logic's
prelude-fallback capability silently retired with the synthetic insert
(known debt, doc-comment updated to reflect). One in-mod core test
relocated to crates/ailang-core/tests/workspace_pin.rs (pd.2.4 dev-dep
cycle precedent — in-mod call to ailang_surface still structurally
impossible).
carve_out_inventory.rs: 8 → 7 carve-outs, §C4(b) row dropped, header
sentence updated. form-a-default-authoring.md §C4(b) gets a "RETIRED
2026-05-14 by milestone prelude-decouple" status marker; original
historical text preserved. New prelude_decouple_carve_out_pin.rs
asserts examples/prelude.ail.json does NOT exist.
Milestone prelude-decouple closed: prelude exists on disk only as
examples/prelude.ail; ailang-core embeds zero prelude bytes; CLAUDE.md
"authors write .ail" doctrine holds without exception.
cargo test --workspace 573 green; bench/cross_lang.py +
bench/compile_check.py exit 0; bench/check.py exit 1 with the
established noise envelope (14th observation of bench_list_sum.bump_s
since audit-cma; pd.3 is filesystem + spec text + test deletion only,
no codegen / runtime / typecheck path edited — baseline pristine).
Folds in the orphan pd.2 INDEX entry that was left uncommitted in the
working tree.
Moved PRELUDE_AIL const + parse_prelude fn to ailang-surface;
re-exported from surface's lib.rs. surface::load_workspace rewritten
3-line shim-call → 7-line composition: load_modules_with → reserved-name
check → inject parse_prelude → build_workspace(&["prelude"]).
Five deletions in core: PRELUDE_JSON, load_prelude, load_workspace_with
(the pd.1 shim), the top-level cfg(test) load_one fn, and the
cfg(test) crate::load_module import. Production literal-"prelude" count
in crates/ailang-core/src/ is now zero. Cross-form-identity preflight
PASSED at module_hash 3abe0d3fa3c11c99 — parse(prelude.ail) ≡
deserialize(prelude.ail.json), so pd.3's deletion of the JSON is safe.
Three new pin tests in ailang-surface/tests/: prelude_parse_pin (succeeds
+ min defs); prelude_module_hash_pin (cross-form-identity + literal-hex
anchor); prelude_injection_pin (inject + reservation).
Plan deviations (recorded in journal): switched the regression-pin
fixture from non-existent examples/hello.ail.json to hello.ail; relocated
10 in-mod core tests to crates/ailang-core/tests/workspace_pin.rs
because the dev-dep cycle (core ↔ surface) prevents in-mod aliasing in
the lib-test target (form-a.1 T5 precedent); preserved load_one
production-symbol-deletion by adding a test-mod-private load_one helper
in core's mod tests for the 2 pd.1-introduced tests still consuming it.
cargo test --workspace 573 green (+9 net from pd.1 baseline).
bench/cross_lang.py + bench/compile_check.py exit 0; bench/check.py
exit 1 with established noise envelope (bench_list_sum.bump_s, 13th
consecutive observation; pd.2 is workspace-loader-only, no codegen
touch — baseline pristine).
Single iter shipping the post-milestone-24 follow-up named in
docs/specs/2026-05-14-retire-per-type-print-effects.md. After this
iter the only surviving direct-output effect-op is `io/print_str`;
all per-type print primitives are replaced by the polymorphic
`print` helper (prelude, iter 24.3).
Components:
- 92 examples/*.ail fixtures migrated (do io/print_<T> x) →
(app print x); 6 .prose.txt snapshots regenerated via `ail prose`.
- Four-site lockstep compiler deletion: crates/ailang-check/src/builtins.rs
(3 effect_ops.insert blocks + 3 list() rows + the
install_io_print_float_signature test + module + EffectOpSig
doc-comments); crates/ailang-codegen/src/lib.rs lower_app
(3 arms + lowers_io_print_float test); crates/ailang-codegen/src/synth.rs
builtin_effect_op_ret match-arm pattern. Dead `intern_string`
helper removed as a follow-up.
- Five incidental test-body migrations (ailang-check x2, ailang-core
spec_drift + design_schema_drift, ailang-surface/src/lex.rs,
ailang-prose/src/lib.rs round-trip test).
- Cat B test-harness patch: six IR-shape tests in
crates/ail/tests/e2e.rs gained a monomorphise_workspace call
before lower_workspace_with_alloc so they follow the same
pipeline as `ail build` (the home-rolled desugar+lift loop
stayed because mono's precondition is "already lifted"; mono
inserts after lift).
- Six doc-comment touch-ups (lex.rs module doc, parse.rs
diagnostic example, ail/src/main.rs x2, runtime/str.c %g anchor,
crates/ailang-core/specs/form_a.md surface-spec example).
- DESIGN.md seven-site sweep (Decision 11 example, Polymorphic
print past-tense, Heap-Str output sentence, effect-op
invocation comment, Float NaN paragraph re-anchored on
float_to_str, two "What is supported" lists).
- Three E2E test-comment polish + four IR-snapshot refresh + one
canonical-hash pin update (plan-unanticipated downstream
consequences of the corpus migration).
- bench/{check,compile_check,cross_lang}.py: all exit 0; no
ratification needed.
- Roadmap entry struck through; per-iter journal at
docs/journals/2026-05-14-iter-rpe.1.md.
Tests 564/0/3. cargo clippy and cargo doc: zero warnings.
Two upstream codegen bugs surfaced during the first BLOCKED
attempt and were fixed in separate iters before this retry:
- 1fb225e bugfix: mono cursor misalignment at poly-free-fn Var
with class-constrained Forall.
- feb9413 bugfix: print leak — propagate ret_mode through rigid
substitution + prelude Show.show ret_mode.
Known debt (carried forward for next /audit):
- Emitter.strings field is functionally dead post-iter (orphan
after intern_string removal); cycles over empty map harmlessly.
Hygiene sweep across the workspace under `cargo clippy --workspace
--all-targets`. Before: 61 warnings. After: zero. Tests stay 563
green, `cargo doc` stays at zero warnings, and all three bench
scripts exit 0 against existing baselines.
Twelve lint classes, three fix shapes:
- Documentation hygiene (~32 hits): `doc_lazy_continuation` resolved
by adding blank lines before continuation paragraphs or rephrasing
the offending line; plus four `empty_line_after_doc_comments` hits
in workspace.rs where eight `///` blocks left orphan by form-a.1
T5 test relocation were converted to plain `//`.
- Idiomatic refactors (~16 hits): `.err().expect()` → `.expect_err()`,
redundant `.into_iter()` and `.into()` removed, `|f| g(f)` →
`g`, `.trim().split_whitespace()` → `.split_whitespace()`,
`push_str("x")` → `push('x')`, two manual `impl Default` flipped
to `#[derive(Default)]` + `#[default]`, two nested `if let Some(_)
= …` collapsed.
- Block extraction (1 hit): a 13-line block inside an `else if`
condition in synth's Var-arm extracted to a new helper
`is_class_method_dispatch(name, env)` next to
`qualifier_is_class_shape`.
Three `#[allow]`s with inline rationale where clippy's suggestion
would lose meaning: `only_used_in_recursion` on walk_pattern (the
parameter preserves the five-fn walker-framework signature
uniformity), 2× `if_same_then_else` on qualify_local_types shapes
(two branches encode semantically distinct disqualification
reasons), `too_many_arguments` on `Emitter::new` (8 workspace-flat
tables; bundling would just rename boilerplate).
Two unrelated hygiene iters bundled because they shipped together
in one autonomous-while-Boss-away batch:
- iter rustdoc-sweep: cleared all 23 `cargo doc --workspace
--no-deps` warnings (17 in ailang-check + 4 in ailang-core + 2
in ailang-surface). Two warning classes: pub-doc-comment links
to pub(crate)/private items (15 hits — replaced with plain
backtick-code-spans), and unresolved/ambiguous links (8 hits
— fully-qualified, disambiguated to fn-form, or escaped).
No behaviour change; tests 562 → 562.
- iter drift-test-narrowing: design_schema_drift.rs now scans
§"Data model" only via new helper data_model_section(),
instead of full DESIGN.md. Closes the audit-form-a-precursor
[high] "anchor-elsewhere-passes-silently" failure mode. All
38 anchors verified pre-edit to live in §"Data model" so the
tightening doesn't regress to red. New pin
data_model_section_is_bounded guards the extractor against
silent regression. Tests 562 → 563.
Six-task post-fieldtest documentary tidy. No production-code behaviour
changes; 559 tests green at every per-task gate.
T1-T3: form_a.md additions
- §Definitions intro "Three kinds" -> "Five kinds".
- New `### Class — (class ...)` subsection: EBNF carries optional
superclass (0 or 1 per ClassDef.superclass schema), method
signatures with optional defaults; anchored to
examples/test_22c_user_class_e2e.ail (ok 24/2).
- New `### Instance — (instance ...)` subsection: EBNF carries the
(method NAME (body LAM-TERM))* shape; canonical-form CLASS-REF
rule explicitly stated (bare same-module / qualified cross-module);
two examples — same-module abbreviated from
mq3_class_eq_vs_fn_eq_classmod.ail and cross-module qualified
from show_user_adt.ail; bare-cross-module-class-ref diagnostic
named inline.
- §Types `(forall ...)` line extended with optional `(constraints
(constraint CLASS-REF TYPE)+)?` clause; explanatory paragraph
added with no-instance diagnostic anchor; fifth example added
to the Examples block anchored to cmp_max_smoke.ail.
T4: docs/specs/2026-05-13-form-a-default-authoring.md "seven
carve-outs" → "eight carve-outs" at 6 sites contradicting the
§C4(b) compile-time-embed amendment (commit 9fcda8b). Sites:
preamble line 11, §C1 line 170, §C2 line 191, §C3 line 218,
§"Data flow" lines 363 + 374. Post-edit grep returns 4 surviving
"seven" lines (233, 238, 463, 469), all correctly §C4(a)-scope
or arithmetic/future-state.
T5: crates/ailang-core/src/hash.rs:50-57 — delete empty
`#[cfg(test)] mod tests {}` placeholder + 6-line relocation
comment. Tests live in crates/ailang-core/tests/hash_pin.rs
since form-a.1 T5; placeholder served no purpose. hash_pin.rs
still 10/10 passing.
T6: crates/ailang-surface/tests/round_trip.rs — module-level
`//!` and inner `///` docstrings rewritten to the post-T10
four-property framing (parse-determinism / idempotency /
CLI-pipeline-idempotency / carve-out-anchor) instead of the
retired Direction-1/Direction-2 language. Sibling-crate
breadcrumbs added pointing at the other two enforcement points
(roundtrip_cli.rs, carve_out_inventory.rs).
Drift item B2 (audit-form-a "plan file two sites") dropped per
recon verification: docs/plans/2026-05-13-iter-form-a.1.md
contains zero defective "seven" sites; all four hits are
internally scoped to §C4(a), arithmetic, or future-state.
Decision recorded in the journal.
Closes 2 of 3 fieldtest-form-a spec_gap findings (#2 form_a.md
typeclass surface + #3 form_a.md class-qualifier rule for
instance) and 3 of 4 audit-form-a drift items.
First half of the form-a-default-authoring milestone-close iter
(Boss-decided strategy C, big-bang). All five tasks DONE; cargo
test --workspace green at every per-task boundary.
T1 — Add three new tests:
- parse_is_deterministic_over_every_ail_fixture (round_trip.rs)
- cli_parse_then_render_then_parse_is_idempotent (roundtrip_cli.rs)
- carve_out_inventory.rs (new file; #[ignore]'d until T8 deletion)
T2 — Bulk-render the 99 missing examples/<stem>.ail files via
`ail render`. Corpus 58 .ail (pre-iter) -> 157 .ail. Eight .ail.json
carve-outs (7 §C4(a) subject-matter + 1 §C4(b) prelude) preserved.
One re-loop triggered: load_workspace prefers .ail siblings since
ext-cli.1, so the newly-rendered imports broke seven Group-A entries
whose JSON entry-paths now resolved imports to fresh .ail. Repair:
pre-emptive forward-pull of five T3 migrations + 4 transient
#[ignore]s on workspace.rs mod tests (cleanly relocated in T5).
T3 — 14 Group-A test files migrated from ailang_core::load_workspace
to ailang_surface::load_workspace + .ail paths. Carve-out lines
preserved verbatim (7 sites in typeclass_22b2.rs / typeclass_22b3.rs).
T4 — 12 Group-B test files: bulk regex flip on build_and_run /
build_and_run_with_alloc / build_and_run_with_rc_stats call sites
(~70 e2e.rs invocations + 11 subprocess sites). Four files
mis-classified Group-A as Group-B in plan recon (mono_hash_stability,
prelude_free_fns, print_mono_body_shape, show_mono_synthesis); two
files mis-classified Group-B as Group-A (mono_recursive_fn,
mono_xmod_qualified_ref). Migrated per actual shape, not plan label.
T5 — Relocated #[cfg(test)] mod tests from production source to
integration test crates with ailang-surface dev-dependency:
- crates/ailang-core/tests/hash_pin.rs (10 tests from hash.rs)
- crates/ailang-core/tests/workspace_pin.rs (10 non-carve-out tests
from workspace.rs)
- crates/ailang-codegen/tests/eq_primitives_pin.rs (3 tests from
codegen/src/lib.rs:3717-3799)
- ailang-prose/tests/snapshot.rs migrated (helper + 8 fixtures) to
.ail + ailang_surface::load_module
Carve-out tests in workspace.rs mod tests preserved in-place
(3× 22b2 + 3× ct1 = 6 tests). Tempdir-based loader-mechanism tests
(3 sites) also preserved — they don't consume examples/.
Tests: 560 passed, 0 failed, 4 ignored (was 558 + 3 T1 new -
1 transit carve_out_inventory #[ignore] = 560 active).
Tasks 6-12 (bench-driver suffix flips, e2e diff-test rewrite + 4
additional raw-JSON-inspect handlers, .ail.json deletion, retiring
obsolete roundtrip tests + schema_coverage corpus flip, §C3
DESIGN.md restatement, §A4 doctrine edits, WhatsNew + roadmap
strike) ship in the next dispatch on this iter ID.
Known debt inherited to T6-12: 4 raw-JSON-inspect tests in e2e.rs
(borrow_own_demo / reuse_as_demo / render_parse_round_trip_canonical
/ ail_run_accepts_ail_source_with_same_stdout_as_ail_json dual-form
smoke) need rewrite or #[ignore] before T8 deletion; recorded in
journal Concerns + Known debt sections.
Closes the loop opened by this morning's .ailx → .ail rename. Every
path-taking ail subcommand (check, build, run, manifest, render,
prose, merge-prose, describe, emit-ir, diff, workspace, deps) now
accepts a .ail (Form A) input as well as .ail.json (Form B). For
.ail paths the subcommand parses through ailang_surface::parse
in-line and proceeds with the same loaded Module value .ail.json
would have produced; binary semantics are extension-agnostic.
Architecture: a new ailang_surface::{load_module, load_workspace}
pair dispatches on file extension. A new injection point
ailang_core::workspace::load_workspace_with<F> lets the surface
crate plug in an extension-aware loader without core having to
import surface (which would close a crate cycle). Import resolution
in workspace::visit now prefers a .ail sibling over a .ail.json
sibling. The CLI binary's 18 callsites switched to the surface
loaders. Surface parse failures route through
workspace_error_to_diagnostic as a new SurfaceParse variant of
WorkspaceLoadError, so `ail check --json foo.ail` on a malformed
.ail returns a parseable JSON diagnostic with code
surface-parse-error instead of the misleading
`json: expected value at line 1 column 1` fall-through.
Boss pre-commit correction: the implementer followed the plan
verbatim and used snake_case `surface_parse_error`, but every
existing diagnostic code in the codebase is kebab-case (verified
via `git grep` over crates/ailang-check/src and crates/ail/src);
realigned to `surface-parse-error` at three sites (the diagnostic
arm + two ct1 test strings). Journal Concerns section records
the correction.
Tests: cargo test --workspace 487 green (+7 from this iter:
1 core unit, 4 surface integration, 1 ail E2E pair, 1 ct1 CLI
diagnostic-shape). bench/check.py, compile_check.py, cross_lang.py
clean on re-run; the latency.{explicit,implicit}_at_rc tail
cluster occasionally flagged on first runs is the same
nondeterministic cluster the previous two audits documented;
baseline left pristine for the third consecutive iter.
Roadmap follow-up "ail check/build/run accept .ail extension" (P2)
removed.
DESIGN.md §Decision 6 / "CLI" bullet gained the symmetric upward
sentence: both .ail and .ail.json are first-class CLI inputs.
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.
Scope (touched):
- 61 example renames examples/**/*.ailx → .ail (git mv)
- 1 rename experiments/.../rendered/ailx.md → ail.md
- 35 content-edited live-toolchain files (crates/, docs/DESIGN.md,
docs/roadmap.md, docs/PROSE_ROUNDTRIP.md, skills/, bench/reference/*.c,
experiment crates under experiments/.../{render,harness,master})
- Experiment-crate cohort rename Cohort::Ailx → Cohort::Ail,
Form::Ailx → Form::Ail, per_cohort/ailx → per_cohort/ail,
{form-only: ailx} → {form-only: ail}, ```ailx → ```ail
Out of scope (deliberately untouched, to preserve honest history):
- docs/journal-archive.md (content-frozen per CLAUDE.md)
- docs/journals/, docs/specs/, docs/plans/, bench/orchestrator-stats/
- experiments/.../runs/ (frozen LLM-output artefacts; models actually
saw .ailx — renaming would falsify the experimental record)
Verification: cargo build/test --workspace green; experiment crate
cargo test green; bench/check.py + compile_check.py + cross_lang.py
all 0-regressed; negative grep for ailx|Ailx|AILX outside the
out-of-scope paths returns zero matches.
Opens immediate follow-up: roadmap.md P2 todo `ail check`/build/run
accept .ail extension — after this rename, .ail is canonical
authoring surface but the CLI still produces a misleading JSON-parse
error on `ail check foo.ail`. That's the next iter.
Milestone-close audit found three drift items (architect) plus
two carry-on items; bench all-green.
Fixes (rt.tidy, boss-direct):
- 5th test parse_then_print_then_parse_is_idempotent_on_every_ailx_fixture
enforces Direction 2 of the Roundtrip Invariant directly. The
DESIGN.md enforcement list grows from four to five tests.
- docs/roadmap.md P1 'Round-trip completeness invariant' entry
retired with one-line journal mirror per roadmap convention.
- DESIGN.md wording sync: <16-hex> → <16-lowercase-hex> for the
Float-bits-hex spelling in the new section (matches §Data model).
Milestone closed clean; five workspace-wide tests anchor the
.ail.json ↔ .ailx bijection plus AST-variant coverage.
Three new reader-only tests pin the .ail.json / .ailx bijection
plus AST-variant coverage. All three passed first observation
across the current corpus — no roundtrip, schema-coverage, or
CLI-drift gaps surfaced.
- every_ailx_fixture_matches_its_json_counterpart (replaces the
3-pair handwritten exhibits): 57 paired .ailx fixtures pass.
- every_ast_variant_is_observed_in_the_fixture_corpus (new): 34/34
AST variants exercised across 136 fixtures; exhaustive matches
without _ wildcard so AST drift fails the build.
- cli_render_then_parse_preserves_canonical_bytes_on_every_fixture
(new): 136 fixtures round-trip through ail render → tempfile →
ail parse with BLAKE3 identity on canonical bytes.
No production code, no DESIGN.md changes (those follow in later
iterations). Tests are pure readers of the repo per spec
acceptance #7 — tempfile crate added as workspace dep for the CLI
roundtrip's intermediate file outside the repo.
Adds seven fixtures under examples/test_22b1_* exercising the
workspace-load coherence checks plus four positive/negative tests in
ailang-core/src/workspace.rs:
- iter22b1_instance_in_class_module_loads_clean: positive case;
test_22b1_orphan_class.ail.json declares Show + instance Show Int
in the same module (the class's). Registry has one entry.
- iter22b1_orphan_instance_fires_diagnostic: declares Show in
test_22b1_orphan_third_classmod, declares instance Show Int in
test_22b1_orphan_third (a third module). Fires OrphanInstance.
- iter22b1_duplicate_instance_fires_diagnostic: per the JOURNAL hint,
module A defines class Show + instance Show MyInt (legal, A is
class's module), module B defines type MyInt + instance Show MyInt
(legal, B is type's module). Entry imports both. Fires
DuplicateInstance with first/second_module distinct.
- iter22b1_missing_method_fires_diagnostic: class Eq with two
non-default methods (eq, ne), instance Eq Int specifies only ne.
Fires MissingMethod { method: "eq" }.
The surface round-trip gate (ailang-surface/tests/round_trip.rs)
filters out test_22b1_* fixtures because the Form-B parser arms for
ClassDef/InstanceDef are deferred to 22b.4. Without the filter, every
fixture's printed text would re-parse-fail on the unknown `class` /
`instance` head.
Test count: 291 → 295 (4 new workspace tests, all green).
Adds Def::Class(ClassDef) and Def::Instance(InstanceDef) variants per
Decision 11 §"Form-A schema". All optional fields (superclass, doc,
default body) carry skip_serializing_if so canonical-JSON bytes of
pre-22b fixtures stay bit-identical.
Downstream match-on-Def sites are extended with explicit Class/Instance
arms. Behaviour for 22b.1 is placeholder (skip in typecheck/codegen,
one-line summary in pretty/manifest, placeholder marker in prose/print)
with TODO comments naming the deferred sub-iters (22b.2 typecheck,
22b.3 codegen, 22b.4 prose-projection arms).
When a fn-param is annotated (own T) but the body never consumes
it (consume_count == 0) and never destructures it via match, the
linearity pass now emits a Severity::Warning diagnostic with a
form-A-rendered (borrow T) rewrite as suggested_rewrite. Pure
advisory, Decision 10 unchanged.
First Warning-severity diagnostic the typechecker emits; three
CLI exit paths gated on Error-only.
JOURNAL: design entry + iter 19a shipping entry.
Closes the 18-arc's stack-recursion limit. Recursive drop
cascades from 18c.4 overflow on long ADT chains (Linux's 8 MB
default stack maxes out around 1M cells of List). The new
opt-in (drop-iterative) annotation on a Def::Type switches the
synthesised drop_<m>_<T> body from recursive to iterative-with-
explicit-worklist for that type.
Schema:
- TypeDef.drop_iterative: bool. Default false; serde-skip
when false so existing fixtures' canonical JSON hashes stay
stable.
- Form-A: (drop-iterative) clause inside (data T ...).
Worklist runtime (4 new ABI symbols in runtime/rc.c):
- ailang_drop_worklist_new(initial_capacity)
- ailang_drop_worklist_push(wl, ptr)
- ailang_drop_worklist_pop(wl) -> ptr
- ailang_drop_worklist_free(wl)
Heap stretchy buffer, doubling on overflow, null-filtering on
push. Lean 4 / Roc precedent documented in the runtime; the
slot-repurposing strategy was considered and rejected because
not every box has a free pointer-typed slot to thread the
worklist through (Cons head is i64, slot 1 is ptr but it's
the field we're following — no free slot).
Codegen (emit_iterative_drop_fn_for_type): for a
drop_iterative type, drop_<m>_<T>(ptr %p) emits a worklist
loop. Fields of the SAME annotated type push onto the
worklist (mono-typed); fields of DIFFERENT types call their
own drop fn directly (recursive on those, but only if THEY
are themselves recursive — i.e. one level of cascade jump
maximum). Mono-typed-worklist is sound for the deep-self-
recursion case the iter targets (List of List of T just
needs the spine flattened).
Tests:
- examples/rc_drop_iterative_long_list — 1M-cell List of Int
with (drop-iterative) annotation.
- alloc_rc_drop_iterative_handles_million_cell_list E2E —
builds + runs under --alloc=rc, asserts clean exit. With
annotation: exits 0. Without annotation (control): SIGSEGV
at exit code 139 (verified by hand). Worklist is load-
bearing.
- iter18e_drop_iterative_emits_worklist_body_no_self_recursion
IR-shape: worklist body has br to loop_head AND no direct
recursive call into drop_<m>_<T>.
- iter18e_no_annotation_keeps_recursive_drop_body — control:
unannotated variant still emits the 18c.4 recursive shape.
- 3 surface parse-tests for the annotation round-trip.
Test deltas: e2e 58 -> 61 (+3), surface 18 -> 21 (+3). All
other buckets unchanged. cargo test --workspace green.
Known debt (deliberate):
- Mono-typed worklist: cross-type drop-iterative fields call
the other type's drop fn directly. A heterogeneous
worklist would be more general but adds tag tracking
complexity for a case (drop-iterative T containing
drop-iterative T') that's narrower than the deep-self-
recursion target. Documented in
emit_iterative_drop_fn_for_type's doc.
- Closure / Type::Var / Type::Forall fields fall back to
shallow ailang_rc_dec via field_drop_call — same as the
recursive variant.
- Dynamic-tag partial-drop fallback (head_or_zero epilogue
shallow dec when moved_slots non-empty) — out of scope per
brief.
Schema floor for explicit reuse hints. Adds Term::ReuseAs
{ source: Box<Term>, body: Box<Term> } with serde tag "reuse-as",
form-A (reuse-as <source> <body>). Schema choice (wrapper, not
modifier-on-Ctor) and rationale recorded in DESIGN.md.
Codegen is identity under all --alloc strategies — lower body,
drop source on the floor. Iter 18d.2 will lower this as the
in-place rewrite under --alloc=rc.
User-facing diagnostics:
- typecheck reuse-as-non-allocating-body: body must be a
Term::Ctor or Term::Lam, the two AST shapes that allocate.
Other shapes (literal, var, app, ...) emit this with a
suggested_rewrite that drops the wrapper.
- linearity reuse-as-source-not-bare-var: source must be a
Term::Var referring to an in-scope binder. Anything else
(literal, nested expression) is rejected here. Suggested
rewrite drops the wrapper.
- linearity use-after-consume at a reuse-as site: source must
not have been consumed earlier in the body. Suggested rewrite
drops the wrapper.
- Visiting reuse-as marks source consumed for the rest of the
body, so a subsequent use of the same binder flags
use-after-consume against it.
Uniqueness inference treats source as Consume — the consume
shows up in the side table for the codegen consumer.
Tests:
- 4 surface parse-tests (round-trip, no-args, one-arg, full
parse_term/term_to_form_a round-trip).
- 1 typecheck unit test (non-allocating body).
- 2 linearity unit tests (non-var source, after-consume).
- 1 integration test (happy-path map_inc in all-explicit mode
is linearity-clean).
- 1 E2E test running the canonical map_inc-via-reuse-as fixture
under --alloc=gc, asserting stdout 9.
- New fixture examples/reuse_as_demo.{ailx,ail.json}.
Test deltas: E2E 55 -> 56, ailang-check unit 43 -> 46,
ailang-check workspace 8 -> 9, surface 14 -> 18. cargo test
--workspace green. No existing fixture's canonical JSON changed.
Brummel