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>
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>
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>
Third docwriter mission (combined). Pure rustdoc additions, no
API or behaviour change.
ailang-codegen (113 LOC of doc):
- Crate root: intra-doc links (emit_ir, lower_workspace,
CodegenError::MissingEntryMain) + precondition note (both
entry points assume type-checked input).
- /// on CodegenError + every variant, naming AST trigger.
- /// on emit_ir and lower_workspace (single vs multi-module
split, cross-linked).
ail CLI (49 LOC of doc):
- Module-level //! expanded from 5 lines to full subcommand
list with one-liners (11 subcommands verified against Cmd
enum), clang-on-PATH note, design-intent paragraph.
Verification: cargo doc --no-deps zero warnings (also under
RUSTDOCFLAGS='-D rustdoc::broken_intra_doc_links'); build green;
tests 64/64 + 3 ignored doctests green. Diff is 100% doc lines
(verified by filtering).
Findings (not fixed; orchestrator-deferred):
- CodegenError::Internal is one catch-all variant for ~30
invariant-violation sites; splitting would help test
ergonomics but is out of doc scope.
- emit_ir synthesises a Workspace with root_dir="."; harmless
today, surfaces if codegen ever reads root_dir.
Process note: my brief said the CLI had 9 subcommands; agent
found and documented 11. Useful counter-pressure on orchestrator
sloppiness — recorded in JOURNAL.
Workspace-wide rustdoc invariant (DESIGN.md item 6) now
load-bearing across all four crates. Docwriter shifts from
sweep to maintenance mode going forward.
Next: 14a (polymorphic list_map using Iter-13a parameterised
ADTs) is unblocked.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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).
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.
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>
Four small cleanups, no semantic change. Workspace is now clippy-
clean (default lints):
- ailang-check: collapse `if-same-then-else` for primitive vs ADT
type lookup into one branch via a local boolean.
- ailang-codegen: iterate `all_strings.values()` directly instead of
`for (_mname, entries) in &all_strings`.
- ailang-codegen: drop `import_map` parameter from `collect_captures`
— was threaded speculatively through every recursive call but
never read.
- ailang-codegen: `s.len()` instead of `s.as_bytes().len()` in
c_byte_len (the warning predates Iter 6).
Tests: 52 still green.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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>
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>
Every fn-value is now a `ptr` to a closure pair `{ ptr thunk, ptr env }`,
not a raw fn-pointer. Top-level fns get an auto-generated adapter
`@ail_<m>_<f>_adapter(ptr %_env, params...)` that ignores env and
forwards to the real fn, plus a static closure constant
`@ail_<m>_<f>_clos = { @adapter, null }`. References to a fn as a
value return the closure-pair address.
Indirect calls now GEP the thunk + env slots, load both, and call
`thunk(env, args...)`. Direct calls to statically-known callees stay
on the original fast path (no adapter).
This is the ABI groundwork for Iter 8b lambdas: a captured-env closure
will reuse the same value shape, just with a non-null env produced by
malloc.
Tests: 48 still green. IR snapshots refreshed (every fn now carries an
adapter + static closure pair). Iter 7's hof.ail.json prints 42
unchanged — `apply(inc, 41)` now hands `@ail_hof_inc_clos` to apply,
which unpacks and indirect-calls as designed.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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>
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>
Symbol-Mangling-Schema einheitlich auf @ail_<modul>_<def> umgestellt
(auch für Single-Modul-Programme), String-Globals als
@.str_<modul>_<idx>. main bleibt LLVM-/C-ABI-Eintrittspunkt und ist
ein Trampoline auf @ail_<entry>_main. lower_workspace emittiert eine
einzige .ll für den ganzen Workspace, alphabetisch nach Modulname,
Cross-Module-Calls über Import-Map aufgelöst. ail build / ail emit-ir
laufen jetzt durch den Workspace-Pfad. IR-Snapshots regeneriert,
neuer ws_main-Snapshot. E2E-Test workspace_build_runs_imported_fn
prüft, dass das Binary die importierte Funktion korrekt aufruft.
Schuld #19 (source_filename) durch einheitliches <entry>.ail-Schema
geschlossen.
- 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>
- 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>
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>
Brummel