Files
AILang/examples/local_rec_let_capture.ail
T
Brummel 6fdb45d2f2 iter rpe.1: retire per-type print effect-ops
Single iter shipping the post-milestone-24 follow-up named in
docs/specs/2026-05-14-retire-per-type-print-effects.md. After this
iter the only surviving direct-output effect-op is `io/print_str`;
all per-type print primitives are replaced by the polymorphic
`print` helper (prelude, iter 24.3).

Components:
- 92 examples/*.ail fixtures migrated (do io/print_<T> x) →
  (app print x); 6 .prose.txt snapshots regenerated via `ail prose`.
- Four-site lockstep compiler deletion: crates/ailang-check/src/builtins.rs
  (3 effect_ops.insert blocks + 3 list() rows + the
  install_io_print_float_signature test + module + EffectOpSig
  doc-comments); crates/ailang-codegen/src/lib.rs lower_app
  (3 arms + lowers_io_print_float test); crates/ailang-codegen/src/synth.rs
  builtin_effect_op_ret match-arm pattern. Dead `intern_string`
  helper removed as a follow-up.
- Five incidental test-body migrations (ailang-check x2, ailang-core
  spec_drift + design_schema_drift, ailang-surface/src/lex.rs,
  ailang-prose/src/lib.rs round-trip test).
- Cat B test-harness patch: six IR-shape tests in
  crates/ail/tests/e2e.rs gained a monomorphise_workspace call
  before lower_workspace_with_alloc so they follow the same
  pipeline as `ail build` (the home-rolled desugar+lift loop
  stayed because mono's precondition is "already lifted"; mono
  inserts after lift).
- Six doc-comment touch-ups (lex.rs module doc, parse.rs
  diagnostic example, ail/src/main.rs x2, runtime/str.c %g anchor,
  crates/ailang-core/specs/form_a.md surface-spec example).
- DESIGN.md seven-site sweep (Decision 11 example, Polymorphic
  print past-tense, Heap-Str output sentence, effect-op
  invocation comment, Float NaN paragraph re-anchored on
  float_to_str, two "What is supported" lists).
- Three E2E test-comment polish + four IR-snapshot refresh + one
  canonical-hash pin update (plan-unanticipated downstream
  consequences of the corpus migration).
- bench/{check,compile_check,cross_lang}.py: all exit 0; no
  ratification needed.
- Roadmap entry struck through; per-iter journal at
  docs/journals/2026-05-14-iter-rpe.1.md.

Tests 564/0/3. cargo clippy and cargo doc: zero warnings.

Two upstream codegen bugs surfaced during the first BLOCKED
attempt and were fixed in separate iters before this retry:
- 1fb225e bugfix: mono cursor misalignment at poly-free-fn Var
  with class-constrained Forall.
- feb9413 bugfix: print leak — propagate ret_mode through rigid
  substitution + prelude Show.show ret_mode.

Known debt (carried forward for next /audit):
- Emitter.strings field is functionally dead post-iter (orphan
  after intern_string removal); cycles over empty map harmlessly.
2026-05-14 02:12:34 +02:00

49 lines
1.9 KiB
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; Iter 16b.3 — LetRec captures of `Term::Let`-bound names.
; `count_below(n)` returns how many integers in 1..=n are strictly
; less than a `threshold` computed locally from `n`. The recursive
; helper `loop` captures the let-bound name `threshold` from the
; enclosing scope; its type is only known after typecheck (the
; let-value is `(app + 5 5)` — an `Int` expression, but the desugar
; pass cannot resolve that without inference).
;
; The 16b.2 desugar pass cannot lift this LetRec (capture is Let-bound,
; not fn-param). Instead the desugar pass leaves the LetRec in place;
; the post-typecheck `lift_letrecs` pass in `ailang-check` resolves
; `threshold`'s type as `Int` from the typechecker's env and produces
; a synthetic top-level fn `loop$lr_0(i: Int, n: Int, threshold: Int)
; -> Int`, rewriting every `(app loop ARGS)` to `(app loop$lr_0 ARGS n
; threshold)`.
;
; Expected stdout (one per line):
; count_below(0) = 0 (empty range; loop's first call has i > n)
; count_below(5) = 5 (1..=5; threshold = 10; all 5 are < 10)
; count_below(15) = 9 (1..=15; threshold = 10; 1..=9 are < 10)
(module local_rec_let_capture
(fn count_below
(doc "Count i in 1..=n with i < threshold, where threshold = 5+5.")
(type (fn-type (params (con Int)) (ret (con Int))))
(params n)
(body
(let threshold (app + 5 5)
(let-rec loop
(params i)
(type (fn-type (params (con Int)) (ret (con Int))))
(body
(if (app > i n)
0
(if (app < i threshold)
(app + 1 (app loop (app + i 1)))
(app loop (app + i 1)))))
(in (app loop 1))))))
(fn main
(doc "Drive count_below at 0, 5, 15. Expected (per line): 0, 5, 9.")
(type (fn-type (params) (ret (con Unit)) (effects IO)))
(params)
(body
(seq (app print (app count_below 0))
(seq (app print (app count_below 5))
(app print (app count_below 15)))))))