Adds a per-fn linearity check that runs on every fn whose
param_modes are all explicit (Borrow or Own, no Implicit), tracks
each binder's consume/borrow state through the AST, and emits
two diagnostics with form-A `suggested_rewrites`:
- `use-after-consume` — a binder is referenced after it has
already been consumed.
- `consume-while-borrowed` — a binder is consumed while a borrow
of it is still live (sibling arg slot, or an enclosing-fn
Borrow param).
Fns with any Implicit param skip the check entirely; that's the
back-compat lane that keeps every existing fixture green. Pure
diagnostic addition: no IR change, no codegen change, no runtime
change.
Each diagnostic carries a non-empty `suggested_rewrites` whose
`replacement` is form-A AILang text (typically `(clone <name>)`).
Adds two new public entrypoints to ailang-surface — `parse_term`
and `term_to_form_a` — so the round-trip
`parse_term(term_to_form_a(t)) ≡ t` is the contract every
emitted replacement must satisfy. Tests assert the contract.
Linearity pass runs only on modules that typechecked clean (any
upstream typecheck error suppresses it for that module — running
on partly-defined IR would produce noise).
Tests: 3 unit tests in `linearity::tests`, 3 integration tests
in `ailang-check/tests/workspace.rs`, 1 serialisation test in
`diagnostic.rs`. `cargo test --workspace` green.
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"]
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>
- ail deps now filters builtins, fn params, and let/match-pattern
bindings. New value_names() in ailang-check::builtins is the single
source of truth shared with the typechecker install path. walk_term
threads a scope set; qualified `prefix.def` refs pass through.
- check_in_workspace returns Vec<CheckError>; check_workspace
accumulates body diagnostics across defs and modules. Pass-1
(top-level symbol table) and per-module type-def setup stay
fail-fast — corrupt env would taint later diagnostics.
- DESIGN.md "What the MVP is NOT" was lying (ADTs, strings landed
in Iter 2/3). Renamed to "What is not (yet) supported" and split
into "not yet" + supported/smoke-tested. JOURNAL Iter 6 entry
records the architecture self-check.
Tests: 47 green (was 44). +2 deps filter tests in e2e,
+1 multi-diagnose test in ailang-check workspace integration.
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>
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.
Brummel