Per the amended heap-Str ABI spec (2a72a4a), static-Str globals lose
the leading UINT64_MAX sentinel rc-header field that hs.1 introduced.
Layout flips from <{ i64, i64, [N x i8] }> <{ i64 -1, i64 N, ... }>
to <{ i64, [N x i8] }> <{ i64 N, ... }>; the IR-Str pointer now lands
on the len-field at struct-index 0 (was 1) via constexpr-GEP. The four
+8 consumer-side GEPs (@puts / @ail_str_eq / @ail_str_compare / @strcmp)
do not change — the bytes still sit 8 bytes past the len-field. Static-
Str pointers are kept out of ailang_rc_dec at the codegen level via
move-tracking (iter 18d.3) and non-escape lowering (iter 18b), so no
header slot is needed at the global; this is a codegen-level invariant,
not a runtime guard.
Change surface: three format strings + two doc-comments in lib.rs,
rename + assertion update of two IR-shape tests, snapshot regen of
hello.ll. No runtime changes, no checker changes, no new fixtures.
Static-Str globals are now 8 bytes smaller per literal.
cargo test --workspace green; cross_lang.py / compile_check.py /
check.py all green. 3 tasks, 0 re-loops.
First iter of the heap-Str ABI milestone. Pure codegen refactor; every existing program produces byte-identical stdout.
Static-Str LLVM globals migrate from `[N x i8] c"…\00"` to `<{ i64, i64, [N x i8] }> <{ i64 -1, i64 N-1, [N x i8] c"…\00" }>`, carrying the UINT64_MAX sentinel rc-header (slot exploited in hs.2 via runtime short-circuit) and an explicit byte length. Two parallel intern paths (`intern_string` for raw format scaffolding, new `intern_str_literal` for language Str values) keep format strings untouched in `[N x i8]` shape.
IR-Str pointers now uniformly land on the len-field (offset +8 from rc-header, -8 from bytes). Four codegen sites that hand a Str pointer to a NUL-terminated-bytes C-API consumer now emit a +8 GEP first: `@puts` (io/print_str), `@ail_str_eq` (eq__Str intercept), `@ail_str_compare` (compare__Str intercept), and `@strcmp` (lower_eq Str arm — the 4th site was not in the plan; surfaced by Task-5 e2e regression and fixed inline).
6 new IR-shape pinning tests; `hello.ll` snapshot regenerated; cross_lang.py + compile_check.py + full `cargo test --workspace` green.
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.
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.
Five polymorphic prelude free fns (ne/lt/le/gt/ge) plus three E2E
fixtures: positive composition over Int/Bool/Str, user-ADT with
user-written Eq/Ord on IntBox, and Float-NoInstance with a
Float-aware diagnostic addendum cross-referencing DESIGN.md §"Float
semantics".
Two checker-side fixes were needed alongside the prelude additions,
both symmetric to the iter 23.4-prep visibility fix:
- linearity::check_module_with_visible — workspace-aware callee-mode
resolution so a Borrow-mode user fn forwarding into a prelude poly
fn (e.g. `at_most x y = not (gt x y)`) doesn't false-fire
consume-while-borrowed.
- mono::collect_mono_targets — distinguish rigid forall vars from
unbound metavars; rigid-bearing free-fn targets skip (they get
re-collected with concrete subst when the enclosing fn itself
monomorphises). Without this, a polymorphic body calling another
polymorphic free fn produced a spurious __Unit specialisation
whose body referenced compare at Unit.
Roadmap split: shipped Eq/Ord half checked, Show + print-rewire half
remains pending behind the heap-Str ABI prerequisite. DESIGN.md
§"Prelude classes" amended.
One pre-existing fixture (test_22b1_missing_method) renamed its
class method ne → tne to avoid collision with the new prelude `ne`.
Bench: check.py + cross_lang.py exit 0; compile_check.py exits 1
with one sub-ms check_ms.local_rec_capture at +26% (tolerance 25%) —
prelude-growth-related noise-band fluctuation, ratifiable per spec
§248-249 and journal Concerns.
Restructure ailang-check/src/mono.rs::monomorphise_workspace into a
single specialiser over every Type::Forall-quantified Def::Fn, covering
both class-method residuals AND polymorphic free-fn call sites in one
fixpoint pass. Remove the codegen-time specialiser (lower_polymorphic_call,
module_polymorphic_fns, mono_queue, mono_emitted, emit_specialised_fn,
plus the now-dead helpers apply_subst_to_term, descriptor_for_subst,
type_descriptor) entirely. Codegen sees only monomorphic Def::Fns after
this iter — no polymorphic call sites, no codegen-time queue.
Architecture changes:
- MonoTarget: struct → enum with ClassMethod / FreeFn variants; dedup
keys are guaranteed-disjoint via 'class'/'free' first component.
- collect_mono_targets: new FreeFnCall channel through synth (cleaner
than the plan's separate-walker proposal — one less data flow,
substitution tracking comes 'for free' via fresh metavars +
post-synth subst.apply). Plan Step 4.4 (polymorphic_free_fns env
field) consequently obsolete.
- synthesise_mono_fn_for_free_fn: new free-fn entry point; substitutes
rigid vars in BOTH the type AND the body (body substitution required
because free-fn bodies carry inner Lams whose param_tys reference
outer Forall vars — adapted from plan's 'body unchanged' sketch).
- mono_symbol_n: N-ary extension of mono_symbol; bit-stable for the
single-type-var case (hash-stability pin Task 1 fires zero times
through all eight refactor tasks).
- rewrite_class_method_calls → rewrite_mono_calls; interleaved-slot
collector preserves the positional-cursor invariant across both
channels.
- workspace_has_typeclasses → workspace_has_specialisable_targets
(principled correctness; old predicate happened to already be true
for every user workspace because the prelude is auto-injected).
Codegen cleanup:
- Two call sites of lower_polymorphic_call deleted (codegen/src/lib.rs
lines ~1939-1945, ~1965-1973).
- lower_polymorphic_call body, module_polymorphic_fns field +
population + Emitter wiring, mono_queue / mono_emitted, drain loop,
emit_specialised_fn — all removed.
- is_static_callee collapsed to module_user_fns-only.
- subst.rs apply_subst_to_term + descriptor_for_subst removed; synth.rs
type_descriptor removed (all dead post-removal).
- ail emit-ir command pipeline gains lift_letrecs + monomorphise_workspace
pre-passes (pre-iter-23.4 the codegen-time poly path was masking
this dependency — emit-ir is now consistent with build).
- Net codegen reduction: -285 lines lib.rs, -93 lines subst.rs.
Tests:
- mono_hash_stability.rs (new): regression pin for six primitive Eq/Ord
mono-symbol body hashes; stayed bit-stable through all eight refactor
tasks.
- mono_unification.rs (new): six tests covering variant-key disjointness,
free-fn target emission, free-fn synthesis with rigid substitution,
rewrite walker on free fns, identity for poly-free-fn-only workspaces,
end-to-end cmp_max_smoke runtime correctness.
- typeclass_22b3.rs: three test sites updated to MonoTarget::ClassMethod
enum form.
- 73 e2e + 18 typeclass + 81 codegen tests all green workspace-wide.
DESIGN.md §'Monomorphisation (post-typecheck, pre-codegen)' amended:
two-arm fixpoint described, disjoint-keyed dedup, cursor-aligned
walker, removed codegen-time path.
Bench check (all exit 0, 112 metrics stable): bench/check.py +
compile_check.py + cross_lang.py.
Plan parent: docs/plans/2026-05-11-iter-23.4.md (fab1685).
Spec parent: docs/specs/2026-05-11-23-eq-ord-prelude.md (841d65d).
Per-iter journal documents two adapted deviations from the plan
(synth-channel vs separate walker; body substitution; emit-ir fix);
no spec defects.
Five tests in crates/ail/tests/ct1_check_cli.rs, each pinning one named property:
- check_json_emits_bare_cross_module_type_ref: --json mode surfaces
`bare-cross-module-type-ref` with non-zero exit on the
test_ct1_bare_xmod_rejected fixture.
- check_json_emits_bad_cross_module_type_ref: same for
`bad-cross-module-type-ref`.
- check_json_emits_qualified_class_name: same for `qualified-class-name`.
- check_human_mode_emits_actionable_message_to_stderr: human (non-JSON)
mode prints both the offending type name and the migration-command
hint to stderr — this path goes through the anyhow/thiserror Display
impl, not workspace_error_to_diagnostic, so it needs its own pin.
- check_ordering_match_post_migration_is_clean: post-migration
ordering_match.ail.json typechecks via the CLI with zero diagnostics,
guarding against revert of the ct.1.5 migration or a regression in
Registry::normalize_type_for_lookup that would reject the canonical form.
`monomorphise_workspace` re-runs `synth` on every fn body to recover
residual class constraints; the env it uses is built by
`mono::build_workspace_env`, which delegates to `build_check_env` and
produces a workspace-flat `ctor_index` (every Def::Type ctor across
every module, keyed by bare ctor name → bare type name).
`check_in_workspace` (lib.rs:1247-1258) explicitly clears that flat
index after `build_check_env` and rebuilds it per-module so that
`Pattern::Ctor`'s local-first / imports-fallback resolution at
lib.rs:2486-2521 keeps the qualified-type-name comparison at
lib.rs:2526 intact: imports-fallback yields a qualified
`resolved_type_name` (`Mod.Type`), local-hit yields a bare one.
The mono pass never does the per-module overlay, so when a body in
module B pattern-matches a ctor `C` whose Def::Type lives in imported
module A, the workspace-flat index resolves `C` locally and yields the
bare type name. The scrutinee, however, was typed against the
qualified name, and the comparison fails with
`PatternTypeMismatch { ctor: "Cons", ty: "A.Type<...>" }`.
Surfaced by iter 23.2 Task 3, which adds `class Eq a` + Eq Int/Bool/Str
instances to the prelude. Pre-Task-3 the prelude is class-free, so
`workspace_has_typeclasses(ws) == false` and the mono pass early-outs
at `mono.rs:73`. Task 3 flips the gate; every workspace now traverses
bodies, which brings the latent bug to the surface for the
pre-existing `nested_ctor_pattern_first_two_sum` and
`std_either_list_demo` E2E tests.
Sibling regressions in the same family: `mono_xmod_qualified_ref.rs`
(env.imports not seeded), commit 13b36cc (env.globals not seeded for
self-recursive fns), commit 5c5180f (env.types / env.ctor_index not
seeded for user ADTs — the original "flat ctor_index" decision that
this bug now exposes as wrong-by-construction for cross-module ctor
pattern resolution).
The minimal fixture is two modules with five defs total:
test_mono_ctor_listmod (data List a = Nil | Cons a (List a)) and
test_mono_ctor_main (class Trivial a + instance Trivial Int + a fn
that pattern-matches Cons against the imported List<Int> + a main).
The test pins the inner cause: matches against the specific
`CheckError::PatternTypeMismatch` variant with the qualified
scrutinee type and bare ctor name, so it stays RED regardless of the
prelude's typeclass content.
Adds three end-to-end tests for the 22b.3 mono pass, each with a
matching one-property fixture under examples/. Defends mono-pass
invariants 3, 4, and 6 from docs/specs/2026-05-09-22-typeclasses.md
at the binary level (stdout-asserting, not AST-asserting):
- coherence_two_instances_pick_correct_body_at_runtime — class R
with instances at Int and Bool, both reachable from one main.
Stdout `11\n22` proves both mono fns are synthesised AND each
call site picks the matching body (no collapse).
- class_default_method_runs_and_prints_default_value — empty
instance body + class-level `default` clause must lower, link,
and print the default value (`99`). Promotes the existing
synthesise_mono_fn unit test to a binary-level guarantee.
- cross_module_class_method_runs_and_prints_correct_value —
class+instance in module A, called from module B's main. The
qualified-name rewrite + cross-module synth-def placement was
AST-tested in 22b.3.6; this pins down the emit-and-link path.
All 18 typeclass_22b3 tests pass; full workspace green; 3 bench
gates 0/0/0.
Four new E2E tests in typeclass_22b2.rs covering invariants the
per-task fixtures (all single-module, single-fn) did not exercise:
- cross_module_class_method_resolves_and_fires_no_instance:
module B's call to `show` (declared in module A) reaches the
no-instance arm, proving Env.class_methods is merged workspace-
wide and not restricted to the local module.
- cross_module_polymorphic_fn_without_constraint_fires_missing_constraint:
same merge guarantees the missing-constraint arm sees the residual
produced by a call to A's class method from inside B.
- cross_module_instance_satisfies_concrete_call: the workspace
registry built at load time over all modules must populate keys
visible from B; a concrete call resolves clean cross-module.
- two_fns_each_missing_constraint_produce_two_diagnostics: pins
check_in_workspace's per-def aggregation — two ill-formed fns
produce two diagnostics (one per fn), not one.
Six new fixtures (xmod_* trio + two_fns_*).
Adds the missing positive counterpart to the no-instance test:
`show 42` with `instance Show Int` PRESENT must typecheck green.
This guards against registry-keying or threading bugs that would
otherwise sneak past the negative-only test (an empty registry at
typecheck time, or a key shape mismatch, would silently fire
no-instance even when the instance exists).
Also drops the dead `let _ = ws;` and its stale comment in
`check_in_workspace` — the line above already consumes
`ws.registry`, so the explicit drop is redundant. The remaining
comment is folded into the registry-threading comment so the
"registry is the only thing threaded" rationale is preserved.
Adds the workspace-global typeclass instance registry per Decision 11
"Resolution and monomorphisation". Built at the end of load_workspace
after the DFS over imports completes; keyed by (class-name, type-hash)
where type-hash uses the new canonical::type_hash (16-hex prefix,
parallel to def_hash and module_hash).
Three coherence checks fire from build_registry, each surfacing as a
distinct WorkspaceLoadError variant:
- OrphanInstance: `instance C T` not in C's or T's defining module.
- DuplicateInstance: two entries share the same (class, type-hash) key.
- MissingMethod: instance omits a required (non-default) method.
The CLI's workspace_error_to_diagnostic is extended with the three new
codes (orphan-instance / duplicate-instance / missing-method).
All existing Workspace { ... } construction sites get the new
`registry` field, defaulting to Registry::default() at synthetic /
test-only paths and threading through ws.registry.clone() at codepath
sites that already hold a real workspace.
Includes hash-stability regression tests (iter22b1_schema_extension_*
and iter22b1_classdef_empty_optionals_hash_stable) and the empty-
registry positive test against examples/sum.ail.json. Test count:
288 → 291 (3 new tests, all pass).
Closes a design hole shipped in 20d: the merge-prose prompt instructed
the LLM to emit JSON-AST and gave a 12-line schema-essentials reminder.
JSON-AST is the canonical hashable artefact, not a writing surface; the
reminder was not a language spec. Foreign LLMs had no realistic shot.
20f makes two coupled changes:
1) The LLM now emits Form-A (the canonical authoring surface fixed by
Decision 6). merge-prose loads the original via ailang_core::load_module
and re-renders via ailang_surface::print before embedding (round-trip
is a gating contract on the surface crate, so this is lossless). The
user runs `ail parse foo.new.ailx` to recover JSON, then `ail check`.
2) crates/ailang-core/specs/form_a.md is the complete LLM-targeted
Form-A specification — grammar, every term/pattern/type/def keyword,
schema invariants, pitfall catalogue, four few-shot modules from
examples/*.ailx. Exported as ailang_core::FORM_A_SPEC via include_str!
and embedded verbatim in every merge-prose prompt.
Drift detection in crates/ailang-core/tests/spec_drift.rs: every variant
of Term, Pattern, Type, Def, Literal is reached via exhaustive `match`.
The arms are not the assertion — adding a new variant without updating
the match is a compile error before the test runs. Once matched, an
anchor string is asserted to appear in FORM_A_SPEC. 8 tests, all green.
The hand-written + mechanical-drift-test combo addresses the user's
"distance to code is too big" concern about a docs-only spec. Generator
overkill rejected: structural drift is mechanically caught, but prose
explanation, schema-invariant catalogue, pitfall list, and few-shot
corpus cannot be emitted from AST shape alone.
Tests:
- ailang-core: +8 spec_drift tests; existing 12 unchanged
- ail unit (3): rewritten in lockstep — assert (own T)/(effects IO)
landmarks, FORM-A SPECIFICATION header, FORM_A_SPEC body verbatim
- ail e2e merge_prose_prints_framed_prompt: rewritten — assert
`(module foo` + `FORM-A SPECIFICATION` instead of `ailang/v0`
- Workspace: all green
Richer integration paths (LLM tool-use, MCP server, LSP) were named
in the design discussion and deferred per "kiss". All three layer
additively on the static-prompt path; static prompt remains the
lowest-common-denominator fallback.
Closes family 20: prose-edit cycle is end-to-end. ail merge-prose
<original.ail.json> <edited.prose.txt> composes a shaped LLM prompt
to stdout. User pipes to their LLM (Claude/etc.), gets new .ail.json,
runs ail check, saves.
No built-in API client — AILang stays a compiler + tooling, the LLM
mediator is supplied externally. PROSE_ROUNDTRIP.md documents the
6-step cycle, the prompt contract (preserve modes/effects/tail
flags from original), failure modes, and the design choice to omit
an API client.
Family 20 now closes: 20a renderer + 20b polish + 20d mediator
shipped; 20c rolled into 20a. Three deferred polishes (let-inlining,
print sugar, doc-wrap widow control) wait for corpus signal.
Three sibling sites previously fell back to shallow `ailang_rc_dec`
when a binder had non-empty `moved_slots` and a dynamic runtime ctor
tag: Iter B Own-param dec at fn-return (lib.rs), Iter A arm-close
pattern-binder dec (match_lower.rs), and emit_inlined_partial_drop's
non-Ctor branch (drop.rs). Shallow freed the outer cell but did not
walk the unmoved ptr fields — silent leak.
Adds `emit_partial_drop_fn_for_type`: a per-ADT helper structurally
parallel to `emit_drop_fn_for_type` but taking an i64 moved-slots
bitmask. Each ptr-field's dec is gated on the corresponding mask
bit; the outer box is dec'd at join. Emitted alongside the per-type
drop fn for every ADT under --alloc=rc.
Three call sites rewritten to resolve the partial_drop symbol from
the binder's static type and build the mask from `moved_slots`.
Three RED-then-GREEN fixtures (rc_own_param_/rc_match_arm_/
rc_app_let_partial_drop_leak) pin the carve-outs in regression
coverage; live cell counts go from 3/1/3 (pre-fix) to 0/0/0.
e2e count: 66 → 69.
The pre-existing `alloc_rc_own_param_dec_at_fn_return` IR-shape
assertion is widened to accept `partial_drop_<m>_<T>(%arg_xs,
i64 mask)` as a third valid drop shape (the canonical fu2 case).
Closes the JOURNAL queue's only remaining iter; the "wait for
organic fixture" stance from the 18g tidy is retracted — known
leaks are bugs, CLAUDE.md's TDD rule covers them autonomously.
Closes the carve-out shared by 18d.4 Iter A and 18g.1's pre-tail-
call seam: a let-binder whose value is Term::Var aliasing a non-
Own fn-param now inherits the param's mode in current_param_modes
for the duration of the let body. Without this, (let a t (match
a ...)) where t is Implicit / Borrow defeated scrutinee_is_owned
(default for non-fn-param scrutinees was 'owned'), and the arm-
close drop fired on pattern-binders whose underlying memory
belongs to the caller — refcount underflow / SIGSEGV on the next
recursion.
Implementation: Term::Let lowering checks if value is Term::Var
referencing a name in current_param_modes; if so, inserts that
mode under the let-binder's name for the body and restores on
let-close (push/pop pattern, symmetric with locals).
Red:
alloc_rc_let_alias_of_implicit_param_does_not_dec_borrowed_children
on examples/rc_let_alias_implicit_param. Pre-fix: SIGSEGV / RC
underflow on the second iteration of loop. Post-fix: matches
alloc=gc ('0').
The Borrow-ret-mode case is already covered by the language-design
rule (typechecker rejects 'consume-while-borrowed' on the
borrow-aliasing shape); the Implicit-mode case is what the carve-
out actually surfaces. Both are now closed at codegen-time.
Two of the three known debts from the 18g tidy now resolved
(stat-of-N earlier in the session, let-alias here). The remaining
debt — tag-conditional partial-drop helper for the dynamic-tag
carve-outs in lower_match and emit_inlined_partial_drop — is the
substantively larger piece and stays queued.
Resolves the architect's drift report on the 18g sub-arc:
- DESIGN.md: ratify mode-metadata's codegen role. param_modes /
ret_mode were already on Type::Fn since 18a; with 18d.4 / 18g
they became load-bearing for drop-emission decisions in
codegen. The new 'Mode metadata is load-bearing for codegen'
subsection records the four seams (Iter A + Iter B + 18g.1 +
18g.2) and names the let-alias-of-borrow carve-out the gates
do not propagate through.
- bench/run.sh: post-throughput, invoke bench/latency_harness.py
on the three canonical arms (Implicit @ gc, explicit @ rc,
Implicit @ rc control). The Boehm-retirement bench numbers
are now reproducible by anyone running the harness, not just
by hand on a specific host.
- Negative coverage: examples/rc_let_implicit_returning_app
+ alloc_rc_let_binder_for_implicit_returning_app_does_not_drop
pin the asymmetry to the (own)-ret-mode test (live=0 there,
live=1 here). The Borrow-ret-mode case is covered by the
language design itself — typechecker rejects 'borrow-
passthrough' shapes with consume-while-borrowed.
JOURNAL entry records four items as deferred known debt:
emit_inlined_partial_drop dynamic-tag fallback, carve-out
diagnostics surface, bench-number stat-of-N, and the
cross-family ordering observation about CLAUDE.md's tidy-iter
rule.
The 18-arc is formally closed with this tidy. Next iter is
the orchestrator's Boehm-retirement decision (Path A vs Path B
from JOURNAL 2026-05-08 18f entry, joined by the post-18g.2
re-bench numbers).
18c.3's is_rc_heap_allocated returned false for any Term::App
shape; the doc-comment explicitly deferred the owned-returning-call
case to 'later iters tied to (own) ret-mode contracts'. We have
those contracts (Iter 18a). With this iter the predicate widens to
recognise Term::App whose callee carries ret_mode=Own; the let-
scope close emits a drop call, routing through the per-type drop
fn derived from the call's return type so the cascade walks ptr
children correctly.
Borrow- and Implicit-returning calls are still not trackable —
they don't carry the static caller-owns-the-return signal.
drop_symbol_for_binder gains an App arm that synthesises the
return type and resolves drop_<m>_<T> from it (same shape as the
existing Ctor arm), with cross-module qualification through
import_map. emit_inlined_partial_drop now defaults to shallow
ailang_rc_dec when value is not Term::Ctor — that path is the
dynamic-tag partial-drop debt 18d.4 already documents (the
runtime tag of a let-binder whose value is Term::App is not
statically known, so per-field partial-drop emission is not
usable; closing this remaining leak path requires a tag-
conditional helper, queued as future work).
Red: alloc_rc_let_binder_for_owned_returning_app_drops_at_scope_close
on examples/rc_let_owned_app_leak — pre-fix live=3 (TNode + 2
TLeaf), post-fix live=0.
End-to-end: bench_latency_explicit under --alloc=rc now reports
allocs=11068575 frees=11068575 live=0. The depth-19 Tree cache
+ all 10M per-op IntList cells deallocate cleanly. Decision
10's prompt-deallocation property now holds end-to-end on the
canonical bench fixture.
Brummel