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>
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>
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.
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.
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>
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>
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.
- 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