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.
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.
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
The Term::Loop arm of write_term rendered binders as bare
`name = init;` statements inside the `loop { … }` body block, which
reads as C/Rust re-init-every-iteration semantics — a projection
lying about a body the prose surface exists to let the reader trust.
Rewrite to a parenthesised init-list on the keyword line,
`loop(acc = 0, i = 1) { … }`, positionally isomorphic to the
unchanged Term::Recur arm. Projection-only: loop/recur AST, Form-A,
JSON-AST, typecheck, codegen, and the Form-A↔JSON round-trip
invariant untouched. RED-first via two new committed
examples/*.prose.txt byte-equality snapshots + two snapshot_loop_*
tests; full ailang-prose suite 10/0; both ail-prose CLI byte-matches
green. Single-iteration milestone, brainstorm→plan→implement.
Spec: docs/specs/2026-05-18-prose-loop-binders.md
Plan: docs/plans/prose-loop-binders.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.
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).
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).
reuse-as: render `(reuse-as src body)` as `reuse src as body` with
adaptive braces — inline for single-line bodies (the 99% Ctor case),
braced for multi-line (Let, Seq, nested Match). Reads as English
subject-verb-object instead of compound keyword + always-block.
let-inlining: `let x = rhs; <body using x once>` collapses to
`<body[x := rhs]>` when (a) rhs is not a `Term::Do` (keep effect
sequencing visible), (b) x is used exactly once (no work duplication),
(c) rhs renders single-line AND ≤ 40 chars (no line smearing). Lossy
projection — round-trip mediator sees the original .ail.json and can
re-introduce a let when the mode model demands it.
Helpers `count_free_var` and `subst_var_with_term` are render-local;
both respect inner shadowing (let, lam, match arm pattern binders,
let rec). Pre-render value at current level + check for newline + len
budget; on inline, write_term_prec gets passed parent_prec so the
substituted term still wraps correctly inside binops.
Snapshot drift: rc_app_let_partial_drop_leak.prose.txt — boilerplate
`let p = build_pair(1)` collapsed into the match scrutinee. Improves
readability. Cons-tower in rc_own_param_drop kept its let thanks to
the length budget (52 chars > 40).
Tests: 59 unit (+ 9 new) + 4 snapshot, all green. Coverage:
inline-single-use, two-uses-keeps, zero-uses-keeps, Do-rhs-keeps,
multiline-rhs-keeps, length-budget-keeps, shadowing-not-counted,
reuse-as inline + braces.
When greedy word-wrap leaves a 1-word last line, pull the
penultimate line's tail word down so the orphan has at least
2 words. Skipped if the combined length would exceed budget
(invariant takes priority over cosmetics).
Visible on nested_let_rec.prose.txt:
before: '...captures outer's param\n/// i.'
after: '...captures outer's\n/// param i.'
Two new unit tests; existing 4 snapshots unaffected (none had
a 1-word orphan).
Eleven binary builtins (+ - * / % == != < <= > >=) render as
lhs op rhs when called with two args (tail-flagged keeps prefix).
Standard Rust-aligned 4-level precedence table elides parens.
not(x) renders as !x. Long /// doc strings wrap at 80 cols on
word boundaries.
bench_list_sum: 'if ==(n, 0)' becomes 'if n == 0', '+(acc, h)'
becomes 'acc + h', tail keyword still visible on tail calls.
19 new unit tests (47 total). 4 snapshots (3 re-rendered + 1 new
bench fixture). Public API unchanged.