Commit Graph

37 Commits

Author SHA1 Message Date
Brummel 76d61aeced Iter 16b.6: LetRec inside polymorphic enclosing fn
Lifts the monomorphic-only restriction. Lifted top-level fn now
becomes Forall(α..., Fn(t..., T...) -> tr) when the enclosing fn
is polymorphic; capture types may mention outer type vars and
the existing mono pipeline (Iter 12b/14a) specializes them
correctly at call sites.

- desugar.rs / lift.rs: scope-building unified — Forall fn-params
  are now KnownType, not LetBound. Lift wraps augmented_ty in
  Forall mirroring the enclosing fn.
- Name-as-value-in-in-term in a polymorphic enclosing fn is
  rejected (eta-Lam wrap from 16b.5 has no Forall). Queued
  separately as closure-conversion-with-polymorphism.
- examples/poly_rec_capture.{ailx,ail.json}: apply_n_times :
  Forall(a). drives at Int and Bool to exercise two mono
  instantiations.
- e2e + check + desugar tests: 116 → 120 (+4).

Codegen pipeline untouched — apply_subst_to_type substitutes
through Fn.params uniformly (original params + appended captures).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 22:39:28 +02:00
Brummel ca507c9f52 Iter 16b.5: LetRec name as value (in_term only) via eta-Lam wrapper
Drops the direct-call-only restriction on the LetRec name when it
appears in `in_term`. No new ABI: the lift wraps the in-term in
`(let f (lam P (app f$lr_N P CAPTURES)) in_term')` so codegen's
existing Iter-8b closure-pair machinery handles it. Body-position
name-as-value still rejected (deferred — eta-of-self is harder).

- desugar.rs / lift.rs: split find_non_callee_use into body
  (panic) and in_term (wrap).
- examples/local_rec_as_value.{ailx,ail.json}: no-capture path
  (factorial passed to apply5 → 120).
- examples/local_rec_as_value_capture.{ailx,ail.json}: capture
  path; lifted fn has captures, eta-Lam picks them up via 8b.
- e2e + desugar tests: 113 → 116 (+3).

Codegen Lam machinery handled the wrapped form on the first try.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 22:27:21 +02:00
Brummel c0668178bb Iter 16b.4: LetRec captures of match-arm pattern bindings
Flips the desugar's MatchArm-capture rejection from panic to defer.
The 16b.3 lift_letrecs pass already handled match-arm bindings via
type_check_pattern_for_lift (Pattern::Var, Pattern::Ctor with sub-
patterns, ctor-field substitution against scrutinee args), so this
iter is a single-line classification change in desugar plus the
fixture and tests that exercise it.

- desugar.rs: MatchArm classification now defers (same arm as
  LetBound); EnclosingLetRec panic remains for 16b.7.
- examples/local_rec_match_capture.{ailx,ail.json}: enclosing fn
  pattern-matches on Pair<Int,Int>, inner LetRec captures both
  match-arm bindings simultaneously. Lifts to
  loop$lr_0(i: Int, threshold: Int, n: Int) -> Int.
- e2e + check + desugar tests: 110 → 113 (+3).

First fixture lifting more than one capture; subst_call_with_extras
already handled it generically.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 22:16:12 +02:00
Brummel ca30606aec Iter 16b.3: post-typecheck lift for LetRec with Let-bound captures
Adds path-2 from the 16b.2 planning entry. Desugar now defers
LetRecs whose captures include Term::Let-bound names; a new
ailang-check::lift_letrecs pass runs after typecheck and uses the
elaborated env to resolve capture types. ailang-check learns a real
Term::LetRec typing rule in synth and verify_tail_positions.

- desugar: Term::LetRec arm gains a defer-arm; helpers promoted to
  pub for reuse by the lift pass; find_non_callee_use moved before
  classification.
- ailang-check::synth/verify_tail_positions: real LetRec rules
  (effect-subset, locals install, recursive name in body+in_term).
- ailang-check::lift.rs (new, 720 LOC): post-typecheck lift with
  post-order traversal, env-walk for capture-type resolution,
  fast-path skip when no LetRec is present.
- ail::main.rs: build path now does load → check → desugar →
  lift_letrecs → codegen.
- examples/local_rec_let_capture.{ailx,ail.json}: new fixture
  capturing a let-bound `threshold` in a recursive helper.
- e2e + check unit tests: 106 → 110 (+4).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 22:07:05 +02:00
Brummel d5f63bc3e5 Iter 16b.2 — LetRec captures of fn-params (path-1 safe subset)
Lift 16b.1's no-capture restriction. The desugar pass's `scope`
becomes a `BTreeMap<String, ScopeEntry>` carrying `KnownType` for
fn/Lam-params, sentinels for Let-/Match-bindings. LetRec captures
of `KnownType` names are lifted: the synthetic top-level fn's
signature gets the capture types appended, and every call site of
the LetRec name is rewritten via `subst_call_with_extras` to pass
the captures positionally. Captures from let-bindings, match-arm
patterns, polymorphic enclosing fns, and name-as-value uses are
rejected at desugar with panics pointing at 16b.3-16b.7.

Demo: `sum_below(n)` recurses via `(let-rec loop (params i) ...
(body ... uses n ...) (in (app loop 1)))`. Lifts to
`loop$lr_0(i: Int, n: Int) -> Int` with `(app loop X)` rewritten
to `(app loop$lr_0 X n)`. Outputs 0, 10, 45.

Tests: 103 -> 106 (+1 e2e local_rec_capture_demo, +2 desugar unit;
the 16b.1 capture-panic test was repurposed into the positive
fn-param-capture test).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 21:00:49 +02:00
Brummel 4683af6114 Iter 16c — literal patterns via desugar
Desugar `Pattern::Lit` (top-level and nested in Ctor) to
`Term::If { cond = (== sv lit), then = body, else_ = fall_k }`.
After 16c, no Pattern::Lit survives the desugar pass; codegen
and typechecker never see one. `is_flat` reclassifies Lit as
non-flat to force the chain machinery; new `build_eq` helper
constructs the equality test per literal kind.

Tests: 99 → 103 (+1 e2e lit_pat_demo, +3 desugar unit). Demo
fixture exercises top-level lit arms (classify) and nested
lit-in-Ctor (categorize_first) with a local IntList; output
100/200/999/-1/0/7.

Known limitations documented in DESIGN.md and JOURNAL: (a)
chain machinery's Unit terminator means non-Wild-terminated
exhaustive matches with lit arms still need a trailing `_`
catch-all to type-check; (b) `==` is currently Int-only, so
Bool/Str/Unit lit patterns desugar correctly but error at
typecheck.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 20:47:21 +02:00
Brummel 8860600e37 Iter 16b.1 — local recursive let (no-capture)
Add `(let-rec NAME (params ...) (type ...) (body ...) (in ...))`
as a form-A surface and a `Term::LetRec` AST variant. The 16a
desugar pass lifts each LetRec whose body has no captures from
the enclosing scope to a synthetic top-level fn `<hint>$lr_N`
and substitutes the original name; typecheck and codegen never
see LetRec. Capture detection panics at desugar time, queued
for 16b.2.

Tests: 95 → 99 (+1 e2e local_rec_factorial_demo, +2 desugar
unit, +1 parse unit). The new fixture `examples/local_rec_demo`
runs `fact` at n=1, 3, 5 → prints 1, 6, 120.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 20:33:48 +02:00
Brummel ee5807d73c Iter 15h — std_list extension: take, drop
Adds the two canonical prefix-slicing combinators to std_list.
First fns in std_list to combine `if` + Int arithmetic + recursive
ADT pattern in one body.

  take : forall a. (Int, List<a>) -> List<a>
       — first n elements (or all of xs if shorter than n).
  drop : forall a. (Int, List<a>) -> List<a>
       — list with first n elements removed (Nil if n >= length).

Both use `(if (<= n 0) ...)` as the base-case guard since
literal sub-patterns inside Ctor patterns aren't yet supported
(queued as 16c — would let take/drop collapse the if into the
match).

examples/std_list_more_demo: builds [1, 2, 3, 4, 5] once and
exercises take/drop at n=0, n=mid, n=overflow on each. Expected
output 0, 3, 5, 5, 3, 0 (one per line).

Tests: 95/95 (e2e went from 35 to 36). std_list grew from 10 to
12 combinators; total stdlib 5 modules / 29 combinators. No new
compiler bug surfaced.

Pre-existing std_list defs are byte-identical (verified via diff
on .ailx and round-trip on .ail.json), so the five downstream
importers (std_list_demo, std_list_stress, std_either_list,
std_either_list_demo, list_map_poly) need no regeneration.
2026-05-07 20:05:45 +02:00
Brummel de674c4d0b Iter 15g-aux — symmetric $u early-return in unify_for_subst
Fix the codegen asymmetry that 15g surfaced. unify_for_subst had an
arg-side-only early-return for $u-prefixed synth wildcards. The
function's prev-binding recursion can swap a $u from arg into param
position when re-unifying a previously-bound type against a fresh
arg. Reduced repro: `length [Left 1, Right 10]` — `a` first binds
to `Either<Int, $u>`, then the recursive unification against
`Either<$u, Int>` lands $u in param-pos[1] and falls through to
the catch-all error.

Fix is three lines: add a symmetric $u early-return for param side.
$u is a synth-only wildcard regardless of which side it ends up on
after the prev-binding swap. Doc comment expanded to record the
origin and justification.

std_either_list_demo refactored: mkleft/mkright workaround helpers
removed; the list is now constructed inline by mixing
(term-ctor std_either.Either Left 1) and (... Right 10) directly.
Same expected output (2, 3, 2, 3); the demo doubles as the 15g-aux
regression fixture.

Tests: 94/94, unchanged. The fix expanded what compiles without
changing observable behaviour for any prior fixture.
2026-05-07 19:59:42 +02:00
Brummel e1587ebdae Iter 15g — std_either_list: first 3-way cross-module stdlib fn
First stdlib fn that imports three other stdlib modules (std_list,
std_either, std_pair) and returns a compound polymorphic ADT tree
(Pair<List<e>, List<a>>). Stresses monomorphisation across nested
parameterised ADTs.

What shipped:
- examples/std_either_list.{ailx,ail.json}: 3 combinators —
  - lefts : forall e a. (List<Either<e, a>>) -> List<e>
  - rights : forall e a. (List<Either<e, a>>) -> List<a>
  - partition_eithers : forall e a. (List<Either<e, a>>)
                        -> Pair<List<e>, List<a>>
  lefts/rights use depth-2 nested Ctor patterns (Cons (Left l) t)
  — exercises 16a's desugar pass at a depth not reached by any
  prior fixture.
- examples/std_either_list_demo.{ailx,ail.json}: drives all three
  combinators on a five-element List<Either<Int, Int>>; expected
  output one per line: 2, 3, 2, 3.
- crates/ail/tests/e2e.rs::std_either_list_demo: e2e count 34 → 35.
- docs/JOURNAL.md: Iter 15g entry.

Compiler bug surfaced (queued as 15g-aux, not fixed):
unify_for_subst in ailang-codegen/src/lib.rs accepts $u wildcards
only on the arg side. Mixing inline (Either Left n) and (Either
Right n) in a list literal lands $u on the param side via the
outer List<a>'s binding and errors. Reduced repro: `length [Left
1, Right 10]`. Demo works around with monomorphic mkleft/mkright
helpers; workaround documented inline. Fix is a one-line symmetric
extension of the early-return.

Tests: 94/94. Stdlib: 5 modules, 27 combinators.
2026-05-07 19:57:06 +02:00
Brummel 689c445d25 Iter 15f: std_pair — 2-type-var product, no recursion
Fourth stdlib module. Pair<a, b> is the canonical product with two
type vars and a single constructor MkPair. Five combinators: fst,
snd, swap, map_first (Pair<a, b> -> Pair<c, b>), map_second
(Pair<a, b> -> Pair<a, c>).

Smallest dogfood for the parameterised-ADT path so far: no
recursion in the data def or any combinator, single-arm matches
throughout. Demo prints 7, 9, 9, 7, 8, 18 deterministically.

No compiler bug surfaced (fourth stdlib iter in a row to land
clean). The only fixable issue was a paren-balance typo in the
demo's seq chain.

Cumulative: 4 stdlib modules, 24 combinators. Type-system surface
exercised end-to-end now spans 1/2/3-type-var data, 1/2/3-type-var
fns, recursive ADTs, cross-module imports of all of the above,
flat and nested patterns, TCO via monomorphised musttail, GC.

Tests: 93/93 (e2e 33 → 34).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 19:12:23 +02:00
Brummel 0e90709a94 Iter 16a: nested constructor patterns via AST desugaring
Lifts the gate that rejected `(pat-ctor Cons a (pat-ctor Cons b _))`.
Approach: a pure AST → AST pass `ailang_core::desugar::desugar_module`
that flattens nested-Ctor sub-patterns into chains of single-level
matches with let-bound fresh vars and duplicate fall-through. Both
ailang-check and ailang-codegen call the pass at pipeline entry.
Hash-relevant canonical bytes are untouched: the pass runs after
load_module, in memory only. `check`'s returned CheckedModule.symbols
still carries hashes of the original defs so `ail diff` / `ail manifest`
see on-disk identities.

Lit sub-patterns inside a Ctor still rejected — that's the narrower
scope of `nested-ctor-pattern-not-allowed` post-16a; the variant doc
reflects the new meaning.

Fresh-name safety: `$` is a valid ident character in form (A), so
the Desugarer pre-walks every Term::Var / Pattern::Var name into a
BTreeSet and bumps its counter past any user-spelled `$mp_N`.

Already-flat matches go through `is_flat()` and emit identical AST
shapes; every existing fixture produces the same output as before.

New: examples/nested_pat.{ailx,ail.json} prints 30 from
first_two_sum on [10, 20, 30]. e2e test
`nested_ctor_pattern_first_two_sum` guards the path.

Tests: 92/92 (e2e 32→33, ailang-core unit 10→12).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 19:10:01 +02:00
Brummel df5b76bd65 Iter 15d: std_either ships — 2-type-var ADT + 3-type-var eliminator
Third stdlib module. Either<e, a> is the first 2-type-var data def,
and the eliminator `either : (e -> c) -> (a -> c) -> Either<e, a> -> c`
the first fn with three type vars on top of the data — the deepest
polymorphism shipped end-to-end so far.

Five combinators: from_right, is_left, is_right, map_right, either.
Demo exercises every one and runs to deterministic output. IR shows
six distinct monomorphisations including two `from_right` variants
(Left=Int vs Left=$u depending on call site) and `either__I_I_I`.

No new compiler bugs surfaced: 14a / 14h / 15b coverage was wide
enough to handle 2-type-var data plus 3-type-var fns out of the box.

Discovered (queued as 15e): `ail render` and `ail parse` are not
symmetric. Form-(A) printer in ailang_surface::print is the actual
inverse of `parse` (round-trip test covers it across all 25 fixtures
including std_either) but is not exposed via the CLI; `render` still
calls the older ailang_core::pretty::module printer.

Tests: 89/89 (was 88, +1 e2e for std_either_demo).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 18:48:43 +02:00
Brummel bd19fee673 Iter 15c: empirical TCO + stack-budget validation at N=1000
Small empirical iter confirming the 14e tail-call story works
dogfood-practical. New fixture std_list_stress.ailx builds a
1000-element List<Int> via recursive build, folds it with both
fold_left (tail-marked in std_list) and fold_right (constructor-
blocked, unmarked), prints both sums (500500 each).

IR evidence at the monomorphised fold-recursion sites:
  fold_left__I_I:  musttail call i64 @ail_std_list_fold_left__I_I(...)
  fold_right__I_I: plain     call i64 @ail_std_list_fold_right__I_I(...)

The tail: true marker on std_list.fold_left's recursive call
survives monomorphisation through the __I_I specialisation.
fold_right correctly emits a plain call (recursive call is
second arg to f, not tail position).

Empirical findings at N=1000:
- fold_left runs in constant stack (musttail).
- fold_right runs in ~1000 frames. No segfault; default 8MB
  Linux stack absorbs it comfortably.
- build (recursive, unmarked) likewise fits.
- End-to-end ~40ms wall (build + clang link); program <1ms.
- Boehm GC handles 2 × 1000 Cons allocations without symptom.

Tests 87 -> 88. Cumulative 30 e2e tests. cargo doc 0 warnings.

Cumulative state, post-15c: 2 stdlib modules (std_maybe,
std_list), 14 combinators, cross-module recursive ADTs working,
TCO surviving monomorphisation, GC at 1000-element scale. Four
compiler bugs surfaced + fixed in dogfood since 14a.

Natural pause point. Queue for future iters: 15d (std_either),
15e (std_pair), 16a (nested patterns), 16b (local rec let),
17a (per-fn arena, Decision 9 future-iter). None block further
stdlib work.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 18:39:16 +02:00
Brummel 92f4b4f8c7 Iter 15b: std_list ships, three more compiler gaps closed
Second stdlib module. Tester wrote std_list.ailx (10 combinators,
164 LOC) and a consumer demo. std_list typechecked standalone;
demo did not, surfacing three compiler bugs:

1. Check-side: Iter 14h's qualify_local_types was applied to
   Term::Var cross-module lookup but not to ctor-field types in
   Term::Ctor synth or Pattern::Ctor resolution. First recursive
   cross-module ADT (List has Cons a (List a) — recursive Con
   self-ref) triggers the bug. std_maybe slipped through because
   Maybe's ctors have no recursive Con field.
2. Codegen-side: same gap mirrored across 4 sites in codegen
   (Term::Ctor synth, lower_ctor, lower_match) plus a tweak to
   unify_for_subst (recurse on re-bind instead of strict equality
   so sibling-derived List<Int> accepts nullary-ctor's List<$u>
   wildcard).
3. Const codegen: emit_const rejected non-literal const bodies.
   The demo's xs : List<Int> = Cons 1 (...) requires it. Fix:
   per-module const table, Term::Var resolution loads literal
   consts from global, inlines non-literal bodies. Bare and
   qualified refs both supported.

All three fixes carry an "Iter 15b" code comment at their site.
~349/25 LOC across ailang-check, ailang-codegen, e2e.rs.

Tests 85 -> 87. New e2e std_list_demo asserts 11-line stdout:
length 5, is_empty false/true, head via from_maybe, tail length,
append length, reverse head, map double head, filter is_even
length, fold_left sum, fold_right sum. New ailang-check unit
test cross_module_recursive_adt_term_and_pat_ctor covers both
the original bug and the symmetric pat-ctor latent twin.

Hash invariance: all pre-15b fixtures + std_maybe defs
bit-identical. 14a / 14e / 14h regressions all green.

Cumulative state: 2 stdlib modules (std_maybe, std_list), 14
combinators, cross-module recursive ADT working end-to-end.
Three compiler bugs surfaced + fixed in dogfood since 14a (each
dogfood iter has surfaced ≥1).

Authoring observation: form (A) at 10 combinators is fine; main
friction is paren-counting in nested seq chains, not the form
itself. n-ary seq would help but is sugar.

Plan 15c: 1000-element list stress test for fold_left (tail-call-
marked) vs fold_right (constructor-blocked).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 18:34:49 +02:00
Brummel 12e9a9c0cc Iter 14h: cross-module parameterised-ADT import (15a unblocked)
The 15a tester surfaced a real compiler limitation: cross-module
type and ctor references were not implemented. Iter 5b only
carried fns + consts via module_globals; types/ctors stayed
module-local with an explicit DESIGN comment. This iter completes
the cross-module mechanism using the Iter-5b convention:
qualified-only access via module.Name.

Implementation:
- ailang-check: Env.module_types populated by build_module_types.
  Qualified resolution in Type::Con, Term::Ctor, with cross-module
  fallback for pat-ctor (local wins, multi-import collision -> new
  ambiguous-ctor diagnostic). Four new unit tests.
- ailang-codegen: workspace-level module_ctor_index replaces
  per-Emitter table. lookup_ctor_by_type / lookup_ctor_in_pattern
  thread qualified type names through box-tag and field-type
  resolution.
- examples/std_maybe_demo.{ailx,ail.json}: type-name slots now
  qualified (std_maybe.Maybe).
- New e2e test cross_module_maybe_demo asserts the demo prints
  ["7","99","true","true","42"].

Net diff ~550 LOC. Tests 80 -> 85. All Iter 14a regressions
(parameterised_box_round_trip, parameterised_maybe_match,
list_map_poly_inc_then_prints, polymorphic_id_at_int_and_bool)
verified green — the 14h derive_substitution change (default
unpinned forall vars to Unit for monomorphiser) sits on a
different layer than 14a's $u-wildcard fix and they coexist.

Hash invariance: all five std_maybe def hashes unchanged. All
80-test-suite fixtures retain bit-identical hashes — cross-module
support is purely additive at the language level.

Process note: the std_maybe.ailx file landed in the 14g commit
via a sloppy git-add-A; should have spotted it before staging.
Not a correctness issue but a hygiene one.

Implementer flagged Unit-default monomorphisation as wasteful-
but-correct; rethink if stdlib grows toward overload-resolution-
style cases needing distinct unconstrained instantiations.

std_maybe stdlib effectively ships: module + four combinators +
e2e-tested consumer demo. Plan 15b: std_list importing std_maybe,
exercising Maybe-returning head/tail and tail-call-marked
fold_left.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 18:08:56 +02:00
Brummel 41d406bcbb Iter 14g: Term::If restored (revert of 14d)
Reconsidered 14d's removal of Term::If. The decision was wrong.
"No redundancies" requires judgment; reducibility (if -> match)
is not redundancy in the strong sense. Term::If is a primitive
control-flow shape; bool branching is the second most common
shape after sequencing, and removing it cost 3x tokens on every
branch site (`(if c a b)` 4 tokens vs the match-on-Bool form
12 tokens).

Meta-pattern fixed: I had been treating user observations as
directives. User said "if is a subset of match"; I jumped to
remove it citing CLAUDE.md, with no independent conviction.
The leak appeared in 14f's JOURNAL prose ("three lines for what
if used to do in one"), which read as regret. Two feedback
memories saved (memory/feedback_user_suggestions_not_directives,
memory/feedback_no_nostalgia_for_removed_features) to head this
off.

Implementation: mechanical reverse-application of 14d's diff at
every site (AST, check including the 14e tail-position arm,
codegen 4 sites, surface parser/printer, pretty, CLI walker,
e2e test mutation). Removed lower_bool_match helper — it existed
only because 14d's migration shape needed codegen for non-ptr
match scrutinees; with Term::If back, match-on-Bool returns to
its pre-14d unsupported state. Three fixtures (sum, sort, max3)
restored to pre-14d shape. gc_stress (added in 14f) also
migrated back to (if ...) since it was authored under the wrong
constraint.

14e (musttail) and 14f (GC_malloc) verified intact in IR.

Hashes restored to pre-14d values:
- sum.sum: db33f57cb329935e
- sort.insert: 697fcb9f30f8633a
- max3.max: 65c45d6a45dd0a72
- max3.max3: 624b14429bf302f5

All other defs across all 18 fixtures keep their post-14f
hashes. Tests 80/80 green; cargo doc 0 warnings. LOC delta
+265/-295 net -30.

DESIGN.md Decision 7 preserved with a "Status: REVERTED" header
for audit trail. Form-(A) `if-term` production restored.

Plan: back to 15a (std_maybe stdlib module).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 17:45:33 +02:00
Brummel ba516b8b39 Iter 14f: Boehm conservative GC
Decision 9 ships. Through Iter 14e every ADT box, lambda env, and
closure pair was leaked. This iter substitutes GC_malloc for malloc
in all four IR allocation sites and links -lgc. No language change,
no AST change, no schema change.

Diff: 5 files modified, ~30 LOC net.
- codegen/lib.rs: 4 substitutions @malloc -> @GC_malloc.
- ail/main.rs: .arg("-lgc") in the clang invocation.
- 5 IR snapshot files: mechanical s/@malloc/@GC_malloc/, 9
  occurrences. IR is bit-identical to pre-14f modulo this
  substitution — exactly Decision 9's promise.
- e2e.rs: new test gc_handles_recursive_list_construction.
- examples/gc_stress.{ailx,ail.json}: new fixture, builds a 50-
  element list via recursive Cons, sums it (1275).

Hash invariance verified: every existing fixture def hash
unchanged (codegen and link line are downstream of canonical
bytes; AST didn't move).

Tests 79 -> 80, all green. Existing 79 byte-identical stdout.
gc_stress -> 1275. list_map_poly -> 2/3/4 unchanged. sort
sorted-list unchanged. cargo doc 0 warnings.

GC notes (pertinent to future work):
- GC_INIT() not needed on Arch libgc 1.5.6 (auto-init via
  __attribute__((constructor))).
- No conservative-scan over-retention observed.
- -lgc alone sufficient for link (pthread/dl transitive).

Pattern-shape note from gc_stress fixture writing: the post-14d
"if-then-else" replacement is `(match (app == n 0) (case
(pat-lit true) ...) (case (pat-wild) ...))`. Three lines for
what `if` used to do in one, but uniform with the language.
Worth flagging for the stdlib brief.

Language is feature-complete enough for stdlib. The three
blockers identified at the 14b boundary (redundancy 14d, tail
calls 14e, GC 14f) are all done. Plan 15a: first stdlib module
std_list.ailx with length/append/reverse/map/filter/fold_left/
fold_right/head/tail/is_empty.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 17:25:07 +02:00
Brummel d64031c234 Iter 14e: explicit, verified tail calls
Decision 8 ships. Term::App and Term::Do gain tail: bool with
serde-default false and skip-when-false serialisation. New
typecheck pass verify_tail_positions enforces tail-position rules
(Scheme-style propagation through match arms, seq.rhs, let body,
lam body). Codegen emits musttail call for marked App calls.

Hash invariance verified: only the two migrated print_list defs
(list_map_poly.print_list, sort.print_list) changed hashes; all
other defs across all 18 fixtures kept bit-identical hashes —
confirms the skip-when-false serialisation rule works.

Tests 76 -> 79: tail_call_in_non_tail_position_is_rejected,
tail_call_in_tail_position_is_accepted, plus an IR-grep e2e test
asserting that print_list's recursive call site emits musttail
in the lowered IR. Existing 25 e2e tests unchanged in behaviour
(map -> [2,3,4], sort -> sorted list).

IR evidence at the recursive site:
  %v7 = musttail call i8 @ail_list_map_poly_print_list(ptr %v6)
  ret i8 %v7

Two deviations called out in the implementer report and JOURNAL:
1. tail-do uses tail call, not musttail. Cross-type return
   (runtime helpers return i32, AILang Unit is i8) would have
   LLVM reject musttail. Path is implemented but not exercised
   by any current fixture; proper fix is runtime-helper signature
   change, punted.
2. block_terminated flag in codegen so tail-call emit
   (musttail call + ret) doesn't get a duplicate trailing ret
   from surrounding code (match-arm phi, fn-body, lambda thunk).
   Internal plumbing; required for IR well-formedness.

Form (A) productions now at ~30, exactly the constraint-1
budget. Future surface additions need to retire something or
explicit-budget-rebalance in DESIGN.md.

GC notes from implementer survey land in JOURNAL:
- Allocations cluster in lower_ctor; every term-ctor does
  malloc(8+8n).
- Tail recursion does not reduce alloc pressure, only stack.
  For map-style ctor-blocked recursions, allocation IS the
  bottleneck.
- Per-fn arena is sound only when fn return type contains no
  boxed ADT. Most current fixtures violate this.

Plan 14f: Boehm conservative GC (GC_malloc, -lgc) as a first
cut. Single-iter integration, no AST/schema change. Stress
test: build a 100k Cons list, observe RSS doesn't blow up.

After 14f the language is feature-complete enough for stdlib
work (15a).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 17:16:28 +02:00
Brummel 8d97a924de Iter 14d: remove Term::If as a redundancy
Term::If was semantically a subset of Term::Match on Bool. Per
CLAUDE.md the language must contain no redundancies; two AST nodes
for the same operation produces an authoring decision with no
semantic content and a duplicate codegen path. Removed.

Migration shape (applied to sum, sort, max3 fixtures):
  (if c a b) -> (match c (case (lit-bool true) a) (case _ b))

No schema version bump (per user direction): no third-party consumes
ailang/v0, so version ceremony is pure overhead. Edited AST and
fixtures in place; pinned hashes in hash.rs updated.

Implementer deviation, called out and justified: a tightly-scoped
lower_bool_match helper (~95 LOC) was needed in codegen because
the existing match path rejects i1 scrutinees and Pattern::Lit.
Helper accepts only the canonical two-arm migration shape, errors
on anything else, emits the same br/phi IR Term::If used to. No
generalisation of the ADT-match codegen.

Diff: 13 files, +286/-221 (net +65 LOC). AST got smaller
(one variant gone), form-(A) got smaller (one production gone),
typecheck got smaller (one branch gone). Codegen got slightly
larger by the bool-match helper.

Hash deltas: sum.sum, sort.insert, max3.max, max3.max3 changed.
All other defs (e.g. sum.main, sort.IntList, sort.sort,
sort.print_list, max3.main) kept bit-identical hashes — confirms
canonical-JSON byte format intact.

Verification: 76/76 tests green; sum->55, max3->17, sort->[1,1,2,
3,3,4,5,5,5,6,9] (identical to pre-migration). cargo doc 0 warnings.

Tail-call survey by implementer (informs 14e): print_list
recursions are already in tail position (rhs of seq inside match
arm); map/sort/insert recursions are NOT (constructor-blocked
inside Cons applications). 14e annotation will benefit terminal
recursions; ctor-blocked ones need accumulator-form rewrites in
source, not a compiler-side transform.

Decision 7 added to DESIGN.md. JOURNAL entry has the language-
completion sequence (14d done, 14e tail-calls, 14f GC, 15a stdlib).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 16:56:02 +02:00
Brummel 706f90bacd Iter 14c: ailang-surface ships — form (A) parser + pretty-printer
Strictly additive new crate per Decision 6 architectural pin.
JSON-AST stays the source of truth; ailang-surface is one
producer/consumer of ailang_core::ast::Module values. ailang-check
and ailang-codegen unchanged.

Crate contents:
- src/lex.rs (~264 LOC): 3-rule lexical core. Whitespace and parens
  delimit tokens; semicolon to EOL is comment; first-character
  classifier (digit -> int, " -> string, else -> ident).
- src/parse.rs (~1041 LOC): hand-written recursive descent. One Rust
  fn per EBNF production. No parser-combinator dep.
- src/print.rs (~371 LOC): deterministic pretty-printer. Round-trip
  contract with parse() is the surface's correctness gate.
- tests/round_trip.rs (~128 LOC): integration test runs every
  examples/*.ail.json fixture through print -> parse -> canonical
  JSON, asserts canonical-byte equality with the original.

Two AST-driven form widenings beyond the 14b sketch (both folded
into DESIGN.md Decision 6):
- lam-term carries (typed name type) params, ret type, and
  optional effects (Term::Lam has parallel param_tys/ret_ty/
  effects fields).
- import-clause admits (import name (as alias)?) (Import.alias
  is Option<String>).

Production count ~28, under 30-rule budget. Constraint 1
(formalisable for foreign LLM) intact.

Verification:
- cargo build --workspace green.
- cargo test --workspace: 76 tests green (was 64; +9 surface unit,
  +2 round-trip integration). All 17 fixtures round-trip
  byte-identical at canonical level. 3 hand-written .ailx
  exhibits parse to canonical JSON identical to their .ail.json
  siblings.
- cargo doc --no-deps zero warnings (DESIGN.md item 6 invariant).

Manual smoke test (ail parse → ail run): hello, box,
list_map_poly all produce expected output through the form-(A)
authoring lane end-to-end.

CLI: ail parse <file.ailx> [-o <file.ail.json>]. .ail.json
remains a first-class input to every existing subcommand.

Plan 14d: stdlib (std_list.ailx with length/filter/fold/concat/
reverse/head/tail), authored in form (A) from day one.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 16:22:14 +02:00
Brummel 2bce825b69 Iter 14b: design pass for the authoring surface
User redirected at iter boundary: writing a stdlib in JSON was
the wrong move. The language is supposed to be the one I program
*best* in, and JSON-AST authoring is rationalisation, not
strength.

DESIGN.md Decision 6 captures the constraints that fall out of
the "formalisable for a foreign LLM" hard requirement (no
precedence, no semantic indentation, ASCII only, every AST node
a uniquely-tagged form), sketches three candidate notations with
the same `map` encoded in each, and picks form (A) — fully-tagged
S-expressions — as the first attempt with explicit rollback path
to form (C) if (A) hurts authoring.

Form (A) shape:
- 3-rule lexical core: sexpr / atom / token-classified-by-
  first-character.
- Every AST node has a unique head keyword. No case-rule (no
  "capitalised head means ctor"); ctors are explicit via
  `(term-ctor TypeName CtorName args)` and `(pat-ctor CtorName
  fields)`.
- Bare atoms get their sort from the parent slot (type-var
  inside `(con NAME args)`, term-var inside `(app HEAD args)`,
  pat-var inside `(pat-ctor CTOR fields)`, integer literal in
  term position, etc.).

Empirical exhibits, hand-encoded:
- examples/hello.ailx          5 LOC (JSON was 36 pretty / 21 canonical)
- examples/box.ailx           25 LOC (JSON was 160 / 88)
- examples/list_map_poly.ailx 50 LOC (JSON was 394 / 230)

4-8x line reduction, ~4x character reduction. Bigger gains on
bigger programs since overhead is proportional to AST depth.
None are parseable yet — header comments say "Iter 14b design
exhibit, parser lands in 14c".

Two small spec issues caught while writing the exhibits and
folded back into DESIGN.md before committing:
- Operator idents (`+`, `==`) need the token-by-first-char
  classification rule, not a word-shaped regex.
- Bool literals (`true`/`false`) reserved in term context;
  unit is explicit `(lit-unit)`.

Tests unchanged (this iter is paper). 25/25 e2e green.
cargo doc --no-deps zero warnings.

Plan 14c: new crate `ailang-surface` with PEG parser, round-trip
hash-equivalence gate against every existing `examples/*.ail.json`,
CLI subcommand `ail parse`. If round-trip holds, stdlib starts
in `.ailx` form (Iter 14d).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 15:57:24 +02:00
Brummel 747b7cd05c Iter 14a: polymorphic List a end-to-end + monomorphisation fix
Dogfood payoff for parameterised ADTs (13a/b/c). Adds the first
program to nest a nullary ctor of a parameterised ADT inside a
parent ctor (Cons(Int, Nil)) and to call a polymorphic recursive
higher-order fn over a recursive parameterised ADT.

Fixture (examples/list_map_poly.ail.json):
- data List a = Nil | Cons a (List a)
- inc : (Int) -> Int = \x. x + 1
- map : forall a b. ((a) -> b, List<a>) -> List<b>
        recursive, instantiated at (Int, Int)
- print_list : (List<Int>) -> Unit !{IO}, recursive
- main builds [1,2,3], maps inc, prints each: "2", "3", "4"

E2E test list_map_poly_inc_then_prints in crates/ail/tests/e2e.rs.

Bug fixed (crates/ailang-codegen/src/lib.rs, +30/-9):
synth_arg_type used Type::unit() as placeholder for ADT type
vars that the ctor's args couldn't pin (Nil for List<a>).
Inside Cons(Int, Nil), unify_for_subst then bound a=Int from
the head and collided with a=Unit from the tail. Replaced the
placeholder with a synth-only wildcard Type::Var{name:"$u"}
mirroring the checker's $m metavar convention; unify_for_subst
short-circuits on $u-prefixed arg-side vars (accept without
binding, let a sibling pin the var).

No schema or API change. No new variant. Tester's recursion
hypothesis was refuted by debugger via a non-recursive
Cons(7, Nil) repro before the fix landed.

Tests: 25/25 e2e (was 24). All Iter 12/13 regressions green.
cargo doc --no-deps zero warnings (workspace invariant from
13d/e/f preserved).

Three-agent flow (tester -> debugger, no implementer needed
since the fix was inside debugger's <50 LOC scope). Process
note in JOURNAL.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 15:32:48 +02:00
Brummel 1631f6065c Iter 13b: codegen for parameterised ADTs
Closes the gap between Iter 13a (parameterised ADTs in the
checker) and end-to-end execution. ADT ctor code stays inlined at
every use site — no mono-queue for types, no new symbols — but
LLVM field types are now derived per use site via substitution.

`CtorRef` gains `type_vars: Vec<String>` so use sites can identify
which fields reference rigid vars. `cref.fields` (precomputed
LLVM strings) is documented as monomorphic-only and read past for
parameterised ADTs.

`lower_ctor`: derives a `BTreeMap<String, Type>` substitution from
`synth_arg_type` of each arg via `unify_for_subst`, then maps every
`ail_field` through `apply_subst_to_type` + `llvm_type` for the
per-store types. Monomorphic ADTs hit the original fast path.

`lower_match`: builds `arm_subst` from `s_ail.args` ↔ `cref.type_vars`,
substitutes through each `cref.ail_fields[idx]`, and uses the
substituted type both for the LLVM `load` AND as the AILang slot
of the local — so a downstream `unbox(b)` sees `b: Int`, not
`b: a`.

`synth_arg_type` for `Term::Ctor`: returns concrete type-args
derived from the ctor's term-args. Vars left unpinned (e.g. `None`
for `Maybe a`) fall back to `Type::unit()`.

`llvm_type(Type::Var)` now hard-errors. Earlier this silently
fell through to `ptr` (the ADT-via-ptr fallback), producing
garbage IR. Failing loudly here surfaces missed substitutions in
the test suite.

Two e2e tests (`box.ail.json`, `maybe_int.ail.json`) cover ctor
lower with substituted field types and match-arm field
substitution. 64 tests green; clippy clean (two pre-existing
warnings untouched). Hash invariant holds.

Out of scope per agent assignment: poly-fn-as-value, higher-rank
polymorphism, DESIGN/JOURNAL updates (deferred to 13c).
2026-05-07 14:45:35 +02:00
Brummel 1fd4763fad Iter 12b: codegen monomorphisation for polymorphic defs
Polymorphic defs are now actually emitted: each unique instantiation
gets its own specialised LLVM fn, mangled @ail_<m>_<def>__<descriptor>.
The typechecker's Forall instantiations from Iter 12a now have a real
backend.

Strategy:
- Pass 1 of lower_workspace splits fn-typed defs into mono and poly:
  module_user_fns keeps LLVM-typed FnSig only for monomorphic fns;
  module_polymorphic_fns holds the full FnDef for poly defs;
  module_def_ail_types is a unified AILang-type lookup for both.
- Direct calls to poly defs (current-module or qualified cross-module)
  flow through lower_polymorphic_call: it derives the type
  substitution from the actual arg AILang types, mangles the symbol,
  and queues (def, subst) for specialisation.
- emit_module drains the queue after the regular defs. Each entry
  produces a specialised FnDef with rigid vars substituted in both
  the type and the body (incl. Lam param/ret annotations), then
  emits via the existing emit_fn pipeline. The synthetic name embeds
  the descriptor; standard mangling produces the right symbol.

Codegen-side type tracking:
- locals tuple grew from (name, ssa, llvm_type) to 4-tuple with
  ail_type. Updated all 6 push sites: fn entry, Let, match-ctor field,
  match-open-arm, lambda capture (cap_meta also extended), lambda
  param.
- CtorRef gained ail_fields parallel to fields, used by match-arm
  bindings to inherit AILang types.
- New synth_arg_type / synth_with_extras: a small recursive walker
  that derives the AILang type of an expression in the current scope.
  Used at poly call sites for arg-type inference. The `extras`
  parameter shadows locals during Let recursion without &mut self.

Helpers added:
- derive_substitution(vars, params, arg_tys): unifies the param
  shapes against the actual args, binding rigid vars; reports
  unbound vars as an internal error.
- apply_subst_to_type / apply_subst_to_term: substitute rigid vars
  throughout a Type or Term (the Term variant only matters for Lam,
  the only Term arm carrying types).
- descriptor_for_subst / type_descriptor: stable identifier-safe
  name suffix. `Int → I`, `Bool → B`, `Unit → U`, `Str → S`, ADT
  `Foo → FFoo`, `Fn → Fn_<...>__r_<ret>`. So `id__I` for id at Int,
  `apply__I_I` for apply at (Int, Int).
- builtin_ail_type / builtin_effect_op_ret: AILang types for the
  builtin operators and effect ops, used by the codegen-side type
  tracker.

Examples + tests:
- examples/poly_id.ail.json: id used at Int (42) and Bool (true).
  Output: 42 / true. Two specialised fns + adapters + static
  closures get emitted (visible in the IR).
- examples/poly_apply.ail.json: apply(succ, 41) == 42. Exercises
  the harder case where one of the polymorphic params is itself
  a function value — the closure-pair ABI survives substitution.
- crates/ail/tests/e2e.rs: polymorphic_id_at_int_and_bool and
  polymorphic_apply_with_fn_param.

Tests: 58/58 (was 56/56). Hash invariant holds: sum.ail.json keeps
db33f57cb329935e / d9a916a0ed10a3d3.

Limitations (known, deferred):
- Polymorphic fns can only be DIRECTLY called. Passing a poly fn as
  a value (let f = id in f(42)) fails — resolve_top_level_fn looks
  in module_user_fns which doesn't include poly defs. Adding this
  needs per-instantiation closure-pair globals.
- No higher-rank polymorphism: a polymorphic arg passed to another
  polymorphic call (apply(id, 42)) trips the simple unify_for_subst
  which doesn't recurse into Forall. Acceptable for the MVP.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 14:10:51 +02:00
Brummel 1d24907f84 Iter 11: deeper dogfood — insertion sort
examples/sort.ail.json: insertion sort over IntList. Defines `insert
:: Int -> IntList -> IntList` and `sort :: IntList -> IntList`
recursively, plus print_list using Iter 10's seq. Sorts an 11-element
input and prints `1 1 2 3 3 4 5 5 5 6 9` one-per-line.

Validates that the language handles deeper ADT recursion + branching
(if + <=) + ctor construction + IO sequencing without surprises.
Wrote, typechecked, ran first try.

The Iter 11 plan called for polymorphism, but on reflection the right
move was one more validation cycle before disturbing the pipeline.
Polymorphism is now queued explicitly as Iter 12 (12a typechecker
substitution, 12b codegen monomorphisation, 12c docs + generic
example).

Tests: 52 green (was 51). New e2e `insertion_sort_orders_list`.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 13:17:07 +02:00
Brummel c75517ac79 Iter 10: Term::Seq sequencing operator
Adds `Term::Seq { lhs, rhs }` (serde tag "seq") as a first-class
AST node for sequencing effectful expressions. Equivalent in
behaviour to `let _ = lhs in rhs`, but the dedicated node gives the
pretty-printer and diagnostics a cleaner shape and surfaces the
intent ("run for effect, then yield rhs") to future tooling.

Typecheck: lhs must be Unit; rhs's type is the result; effects
accumulate.
Codegen: lower lhs (drop SSA), lower rhs (return).
Capture / deps walkers: recurse into both sides.

Refactored examples/list_map.ail.json's print_list to use seq
instead of `let _ = ...`. Output unchanged (2/4/6).

Hash stability: existing examples without Term::Seq serialise
bit-identical; only list_map.ail.json's hashes changed (deliberate
refactor).

Tests: 51 green (was 50). New unit test
`ailang_check::tests::seq_lhs_must_be_unit` covers the type-error
path; existing list_map e2e covers the happy path.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 13:14:28 +02:00
Brummel 849eca4fcf Iter 9a/9b: dogfood (list_map) + ail run
Iter 9a — dogfood. examples/list_map.ail.json exercises everything
Iter 1-8 shipped in one program: ADTs (IntList = Nil | Cons Int IntList),
recursive fns over the ADT (map_int, print_list), pattern matching with
nested Var fields, a closure (`\\x. x * 2`, no captures), fn-typed
parameters, IO effects propagating through recursion, and `let`-
sequencing of an effectful sub-expression inside a match arm.

Result: nothing broke. The full pipeline (typecheck → IR emit →
clang → run) produces "2\\n4\\n6\\n". The language is now sufficient
for "small but real" programs.

Iter 9b — `ail run`. Convenience subcommand that builds into a
tempdir and executes, propagating the binary's exit code. Equivalent
to `ail build && ./bin` in one step. Build logic factored out of
`Cmd::Build` into a shared `build_to` helper used by both Build and
Run.

Tests: 50 green (was 49). New e2e `list_map_doubles_then_prints`.
No test for `ail run` itself — the existing build_and_run helper in
e2e.rs already exercises the same build+exec sequence path.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 13:09:18 +02:00
Brummel ecde8fa7af Iter 8b: lambdas with capture (Term::Lam + closure conversion)
Adds anonymous functions to AILang. A lambda value is constructed by
malloc'ing an env struct that holds its captured locals, plus a
closure pair `{ thunk_ptr, env_ptr }` (Iter 8a's ABI). The lambda's
body lifts to a top-level thunk `@ail_<m>_<def>_lam<id>(ptr %env,
params...)` that unpacks captures back into named locals before
running.

AST: new Term::Lam { params, paramTypes, retType, effects, body }.
Serde tag is "lam"; existing modules (no Lam) serialize identically,
so all current hashes stay stable.

Pretty-printer: renders `(\\ (x: T ...) -> R . body)`.

Typecheck (ailang-check): a lambda's type is the declared Type::Fn.
Body's effect set must be a subset of declared effects (no row
polymorphism). Constructing a lambda is pure — only calling it picks
up the declared effects, via the existing App branch.

Codegen (ailang-codegen):
- collect_captures: free-var walk; excludes builtins, current-module
  top-level fns, and qualified names.
- lower_lambda: per-fn lam counter, save/restore emitter state, emit
  thunk into a deferred queue (flushed after the parent fn), pack env
  + closure pair on heap, register the resulting closure-pair SSA in
  the sidetable so subsequent indirect calls find it.
- Capture sigs propagate: a fn-typed capture keeps its FnSig in the
  thunk's sidetable so `f(args)` inside the body still indirect-calls.
- Env layout: 8 bytes per capture (typed load/store reads only the
  needed bytes; padding wasted but uniform).

Tests: 49 green (was 48). New examples/closure.ail.json + e2e
`closure_captures_let_n` exercises `let n = 3 in apply(\\x. x + n, 39)`
end-to-end and asserts the binary prints 42.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 13:03:20 +02:00
Brummel c6c0a10788 Iter 7: first-class function references (no capture)
Top-level fn names are now usable as values, fn-typed parameters can
be called as `f(args)`. KISS slice of "closures + HOFs + TIR": no
TIR, no heap, no ABI shift — that bundle stays in Iter 8 where
closure-with-capture and lambdas land together.

Codegen:
- Type::Fn lowers to LLVM `ptr`; sig travels via a per-fn-body
  `ssa_fn_sigs` sidetable on `Emitter`.
- Term::Var falls through to `resolve_top_level_fn` when the name is
  not a local; emits `@ail_<m>_<def>` and registers the sig.
- Term::App splits: static callee (builtin / current-module / qualified)
  keeps the existing direct path; otherwise lower the callee, look up
  the sig, emit indirect `call <ret> (<param-tys>) %fn(args...)`.
- emit_fn registers fn-typed params in the sidetable on entry.
- If branches propagate a fn-pointer sig to their phi when both arms
  match.

Typechecker: unchanged. It already accepted `synth(callee)` against
Type::Fn; the only blocker was codegen rejecting non-Var callees.

Tests: 48 green (was 47). New `examples/hof.ail.json` and e2e
`higher_order_apply_inc` exercise `apply(inc, 41) == 42` end-to-end.

DESIGN.md: "What is not (yet) supported" rewritten — closures-with-
capture and lambdas remain pending, first-class fn-refs added as
positive bullet. Smoke-test list extended with `hof.ail.json`.

JOURNAL.md: Iter 7 entry with rationale, scope choice, architecture
self-check, Iter 8 plan.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 12:44:10 +02:00
Brummel efd209779c Translate remaining German content to English
Finishes the project-wide English convention:
- CLAUDE.md (the user opted in to translate it too).
- examples/hello.ail.json: "Hallo, AILang." -> "Hello, AILang.".
- E2E test assertion and IR snapshot for hello regenerated to match.
- DESIGN.md "Project language: English" section: the previous
  CLAUDE.md exception is dropped.

After this commit, no German remains in any committed file
(grep -P '[äöüÄÖÜß]' is empty across .rs / .md / .json / .ll).

Verified: cargo test --workspace passes (44/44).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 12:20:18 +02:00
Brummel b2878fe655 Iter 5b: Cross-Module-Typcheck mit qualifizierten Verweisen
Neue API check_workspace(&Workspace) -> Vec<Diagnostic>; check_module
hebt das Modul intern in einen Trivial-Workspace. Term::Var mit genau
einem Punkt im Namen ist ein qualifizierter Verweis <prefix>.<def>,
aufgelöst über Import-Map (alias-oder-modulname → echter Modulname).
Drei neue Diagnostic-Codes: unknown-module, unknown-import,
invalid-def-name. ail check lädt jetzt immer via load_workspace;
Loader-Fehler werden im JSON-Modus zu strukturierten Diagnostics
(module-not-found, module-cycle, …). DESIGN.md und JOURNAL.md
dokumentieren die Konvention. Hash-Stabilität: alle ir_snapshot_*-
Tests bitidentisch grün, kein neuer AST-Knoten.
2026-05-07 11:31:57 +02:00
Brummel 3451b5bd15 Iter 5a: Workspace-Loader mit Imports
ailang_core::Workspace + load_workspace folgt imports-Feld rekursiv
vom Eintrittsmodul. DFS mit Zyklus-Erkennung; Konvention: Modulname
== Dateiname (.ail.json). WorkspaceLoadError sammelt strukturiert:
Cycle, ModuleNotFound, ModuleNameMismatch, Schema, Io. Neues
ail workspace <entry> [--json] listet erreichbare Module mit
module_hash und Def-Count. Bestehende Subkommandos arbeiten weiter
pro Einzelmodul (Iter 5d).
2026-05-07 11:23:21 +02:00
Brummel 93fe7237e3 Iter 4a: ail check --json mit strukturierten Diagnostics
Neue Top-Level-API check_module(&Module) -> Vec<Diagnostic> in
ailang-check, plus stabile Codes (unbound-var, type-mismatch,
arity-mismatch, non-exhaustive-match, unknown-ctor-in-pattern,
duplicate-def, …). CLI bekommt --json-Flag für maschinenlesbares
Output, Exit 1 bei Errors. Text-Modus unverändert. E2E-Test
check_json_unbound_var sichert das Format ab.
2026-05-07 11:07:36 +02:00
Brummel 21606c9340 Iter 3: ADTs + Pattern Matching
- AST: Def::Type mit Ctors; Term::Ctor (Konstruktion) und Term::Match
  mit Arm/Pattern. Patterns: Wild, Var, Lit, Ctor { ctor, fields } —
  Sub-Patterns im MVP auf Var/Wild beschränkt.
- Typchecker: Type-Registry, ctor_index für O(1)-Resolution, Pattern-
  Bindings, Exhaustiveness-Check gegen volle Konstruktormenge plus
  Negativ-Tests.
- Codegen: Boxed-Heap-Layout via malloc; Tag in Offset 0, Felder ab
  Offset 8 in 8-Byte-Slots. Match lowert zu load tag + switch + Phi
  am Join. Default-Block ist unreachable, wenn vom Typchecker geprüft.
- examples/list.ail.json: rekursive Int-Liste mit sum_list via match.
  E2E-Test + Exhaustiveness-Tests. 19/19 Tests grün.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 10:38:07 +02:00
Brummel 6e6b6a14fb Iter 2: verschachteltes if, Strings, JSON-Output, deps
- Codegen: current_block-Tracking ersetzt die Heuristik im phi-Lowering;
  verschachtelte if-Ausdrücke produzieren jetzt korrekte LLVM IR.
  examples/max3.ail.json + Test schützt gegen Regression.
- Strings: Lit::Str / Type Str / io/print_str Effekt-Op; Strings sind im
  MVP immutable Konstanten. examples/hello.ail.json als zweiter E2E-Test.
- CLI: --json für manifest und builtins; neuer deps-Subcommand listet
  statische Symbol-Referenzen pro Definition. Effekt-Ops mit Prefix
  effect: markiert.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 10:28:16 +02:00
Brummel 2fbcdba0b1 MVP: AILang-Sprache mit JSON-AST, Typchecker, LLVM-IR-Backend
Erste lauffähige Iteration. examples/sum.ail.json wird zu nativem Binary
kompiliert und druckt 55 (Summe 1..10) als End-to-End-Test.

Architektur:
- ailang-core: hashbares JSON-AST + canonical-form + pretty-printer
- ailang-check: monomorpher HM-Subset + Effekt-Set-Tracking
- ailang-codegen: LLVM-IR-Text-Emitter (kein libllvm-link)
- ail: CLI mit check/manifest/render/describe/emit-ir/build/builtins

Designentscheidungen sind in docs/DESIGN.md dokumentiert; der Verlauf
in docs/JOURNAL.md.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 10:18:32 +02:00