Commit Graph

26 Commits

Author SHA1 Message Date
Brummel 7dfc88a4f3 Iter 18c.1: Term::Clone schema (no inc emission yet)
Adds (clone X) as a new Term variant. Form-A:
  (let p (expensive_fn x)
    (do consume_a (clone p))    ; explicit RC inc — needs 18c.3
    (do consume_b p))

Schema floor for the LLM-aware RC design (Decision 10): explicit
clone is the author-visible alternative to implicit sharing. In
18c.1 the variant is purely additive — typechecker treats it as
identity (same type as inner), codegen lowers it to the inner
term's IR with no extra calls. Iter 18c.3 will replace the
codegen identity-arm with a single call:

  Term::Clone { value } =>
      let v = self.lower_term(value, ...)?;
      self.emit("call void @ailang_rc_inc(ptr {v})");
      Ok(v)

Match-arm count: ~10 sites across 6 files, all mechanical
structural recursion through `value`. The codegen `lower_term`
arm carries an explicit comment marking the 18c.3 emission seam.

Hash invariant: `(clone X)` uses a new serde tag "clone" that no
pre-18c.1 fixture contains. Every existing fixture's canonical
JSON is bit-identical (git diff examples/ empty).

New fixture examples/clone_demo.{ailx,ail.json}:
  (let x 42 (do io/print_int (clone x)))
Stdout 42 under both --alloc=gc and --alloc=rc.

Tail-position propagates through clone (verify_tail_positions
treats `(clone tail-call)` as itself a tail call), per the
identity-of-clone semantics in 18c.1.

Verified:
- cargo build --workspace clean
- cargo test --workspace green: 52 e2e (+1), 14 surface parse
  (+2 for clone tests), all other buckets unchanged
- ail render round-trip exact
- clone_demo --alloc=gc → 42; --alloc=rc → 42
2026-05-08 02:26:12 +02:00
Brummel b9ca8894a5 Iter 18a: (borrow T) / (own T) mode annotations on fn signatures
Adds form-A surface (borrow T) / (own T) wrappers in fn-type
params and ret slots. Internally these are not new Type variants
but per-position metadata on Type::Fn:

  Type::Fn { params, param_modes, ret, ret_mode, effects }
  enum ParamMode { Implicit, Own, Borrow }

This keeps Type itself unchanged, so unification, occurs, apply,
and ~190 other Type match-arms in the typechecker need no new
branch. Fields use serde skip-if-default predicates so canonical
JSON hashes for every pre-18a fixture stay bit-identical (sum,
list, hof, closure, list_map, etc.: zero diff under git).

Iter 18a is purely additive: typechecker treats modes as
transparent (mode-compat check deferred to 18c), no codegen
change (--alloc=gc / Boehm path unchanged), no linearity
enforcement. The annotation info flows into the JSON side-table
that 18c will consume.

Equality of mode slices is length-tolerant: a vec![] (the form
written by mechanically-updated construction sites that elide
modes) compares equal to vec![Implicit; n]. This kept the patch
from being a 100-site mechanical migration through the
typechecker. 18c will choose: keep the slack, or normalise to
full-length on construction.

New fixture examples/borrow_own_demo.{ailx,ail.json} exercises
both modes. list_length declares (borrow (con List)); sum_list
declares (own (con List)). Stdout: 3 then 6.

Documentation: DESIGN.md schema-additions block clarified that
modes are Type::Fn metadata (not Type variants); migration plan
flag rename --memory=rc → --alloc=rc to match the existing CLI
flag.

Verification:
- cargo build --workspace green
- cargo test --workspace green (154 tests, +1 vs baseline 153)
- git diff examples/{sum,list,hof,closure,list_map,...}.ail.json: empty
- borrow_own_demo runtime stdout: "3\n6\n"
- canonical JSON contains "param_modes":["borrow"] and ["own"]
2026-05-08 02:07:07 +02:00
Brummel af35612c1d Iter 16d: chain-terminator via __unreachable__ builtin
Eliminates the Unit-typed chain default that 16c left in place.
Adds __unreachable__ : forall a. a — codegen lowers to LLVM
unreachable. The 16a/16c chain machinery now uses it as the
deepest fall-through, so exhaustive matches with non-Unit arms
no longer need a (case _ ...) workaround.

- check/builtins.rs: register __unreachable__ as Forall(a, a).
- codegen: Term::Var "__unreachable__" emits LLVM unreachable
  and sets block_terminated; If/Match/fn-body gate downstream
  work on that flag.
- desugar: chain default switched from Lit{Unit} to Var.
- examples/lit_pat: categorize_first's trailing _ arm removed.
  Hash changes from c4faec3abc2ed388 to 644de0c0ec15fc17.
- examples/unreachable_demo: positive fixture using safe_div
  with __unreachable__ in the impossible branch.
- e2e + desugar tests: 122 → 124 (+2).

Path-a from 16b.2 planning: real primitive over a desugar-time
exhaustiveness pre-check (which would need cross-module type
registry access from desugar).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 23:00:23 +02:00
Brummel e5f9828a04 Iter 16b.7: nested LetRec mutual capture (params, not name)
Inner LetRec capturing outer LetRec's params now lifts cleanly via
the existing post-order traversal — outer's params are KnownType
in inner's outer-scope, so 16b.2's fast-path handles them. Inner
LetRec capturing outer's NAME remains rejected (closure-of-self
in body, deferred separately).

Plus hardening: lift.rs's deferred path tracks the outer LetRec
name in a parallel `enclosing_letrec_names` set so the symmetric
inner-captures-outer-name rejection fires there too — without it
a silent lift produced a runtime arity mismatch.

- examples/nested_let_rec.{ailx,ail.json}: outer counts down via
  inner that captures the outer's threshold param.
- desugar.rs: clarified panic message for outer-name capture.
- lift.rs: enclosing_letrec_names tracking.
- e2e + desugar tests: 120 → 122 (+2).

End-of-16b series: feature-complete except for closure-of-self
in body and closure-with-polymorphism, both queued separately.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 22:48:14 +02:00
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 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 0b1b39f829 Iter 15e: render is the exact inverse of parse — CLI hygiene
The CLI help text claimed `render` was symmetric to `parse`, but
`render` was wired to ailang_core::pretty::module (an older
human-pretty form) while `parse` consumed form (A). Two different
"text projections" coexisted under one name.

Fix: Cmd::Render and Cmd::Describe (both branches) now call
ailang_surface::print, the actual inverse of `parse`. Round-trip
gate via `ail render | ail parse` is now an e2e test in
crates/ail/tests/e2e.rs in addition to the existing unit-level
round-trip across all 25 fixtures in ailang-surface/tests.

Cleanup: `ailang_core::pretty::module` and its three private
helpers (`def_block`, `term_block`, `term_inline`) deleted —
~260 LOC of duplicate-purpose code removed. pretty.rs goes
from 457 to 196 LOC. Surviving surface is intentionally narrow:
manifest, type_to_string, pattern_to_string — the diagnostic
stringification used in error messages, where one-line ML
notation reads better than form (A)'s nested S-expressions.
Module-level doc rewritten to nail down the single-purpose
framing.

Tests: 89/89 (e2e +1, ailang-core unit -1 since the deleted
test exercised the deleted fn).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 18:54:07 +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 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 c90926dbba Iter 13d: rustdoc polish for ailang-core + new docwriter agent
Adds ailang-docwriter to /agents/ — a recurring role for keeping
crate-, module-, and pub-item-level rustdoc accurate. First mission:
ailang-core. Crate root, every module root, every pub item documented;
intra-doc links throughout; Iter-13a additions (TypeDef.vars, Type::Con.args)
get an explicit backwards-compat note. Two stale broken-link warnings in
ailang-check fixed in passing. cargo doc --no-deps now warning-free across
the workspace; promoted to verification invariant 6 in DESIGN.md.
2026-05-07 15:02:35 +02:00
Brummel 078262271a Iter 13a: parameterised ADT schema + checker
Adds type parameters to ADTs. `TypeDef` gets a `vars: Vec<String>` and
`Type::Con` gets an `args: Vec<Type>`, both `skip_serializing_if =
"Vec::is_empty"` so canonical-JSON hashes of every pre-13a definition
stay bit-identical (regression test in `hash::tests`).

Checker:
- `check_type_def` installs `td.vars` as rigid vars while validating
  ctor field types — `Cons(a, List a)` now resolves both occurrences
  of `a` and the recursive `List a` use.
- `check_type_well_formed` accepts `Type::Con { name, args }` only
  when the type is in scope and `args.len()` matches its declared
  arity; primitives stay zero-arg.
- `Term::Ctor` synth instantiates `td.vars` with fresh metavars, so
  `MkBox(42)` synthesises to `Box<$m0>` and unifies field types
  through the surrounding context.
- `type_check_pattern` substitutes the scrutinee's concrete type-args
  through ctor field types, so a `MkBox(x)` arm against a `Box<Int>`
  scrutinee binds `x : Int`.
- `check_fn` validates declared param/return types via
  `check_type_well_formed` so arity mismatches on parameterised
  ADTs surface before the body is checked.

`unify`, `occurs`, `Subst::apply`, `substitute_rigids`, and codegen's
`unify_for_subst` / `apply_subst_to_type` recurse into `args`.

Pretty-print:
- `type_to_string` renders `Box<Int>` for parameterised cons.
- `def_block`/`manifest` carry the `[a b ...]` vars list.

Three new check unit tests cover ctor instantiation at a concrete
arg, the polymorphic-`unbox` round trip at two distinct
instantiations, and arity mismatch on `Box<Int, Bool>`. All 62 tests
green; clippy clean (two pre-existing warnings untouched). Hashes
db33f57cb329935e (sum) and b082192bd0c99202 (IntList) verified
unchanged.

Codegen still synthesises `Type::Con` with `args: vec![]` from
`Term::Ctor` — full ADT monomorphisation lands in 13b.
2026-05-07 14:25:58 +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 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 7577ab8a90 Translate project content to English
Make English the project-wide language: all comments, string literals,
CLI help text, design docs, journal, agent prompts, and README. Only
CLAUDE.md (the user's own instruction file) stays German, and the live
conversation between user and Claude continues in German.

Adds a new "Project language: English" section to docs/DESIGN.md as
the durable convention. No logic changes — translation only. Four
internal error strings in the typechecker were retranslated; no
test asserts on their wording.

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

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-07 12:17:48 +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 c652b12582 Iter 4b: ail diff für semantischen Modul-Vergleich
ail diff <a> <b> [--json] vergleicht zwei Module strukturell per
Def-Hash. Vier Kategorien (added/removed/changed/unchanged),
alphabetisch sortiert, deterministisches JSON-Schema. Exit 1 bei
Unterschieden, Exit 0 bei Identität — skript-tauglich. Kein
Typcheck-Zwang, damit man auch kaputte Module diffen kann. Helper
def_name/def_kind in ailang-core für stabile Def-Identität.
2026-05-07 11:11:48 +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