Brummel
26fb3459d8
The runtime print path now writes exactly the bytes of its
argument with no implicit trailing newline. `io/print_str` is
byte-faithful; authors who want a newline emit `(do io/print_str
"\n")` themselves.
## Codegen
`crates/ailang-codegen/src/lib.rs`:
- Module preamble: `@puts(ptr)` → `@fputs(ptr, ptr)` plus
`@stdout = external global ptr` (libc's `FILE *stdout`).
- Effect-op lowering for `io/print_str`: emit
`getelementptr +8` then `load ptr, ptr @stdout` then
`call/tail call i32 @fputs(ptr bytes, ptr fp)`. Identical
bytes-pointer GEP, distinct sink.
- The pinned IR-shape test renames from
`print_str_calls_puts_with_bytes_pointer` to
`print_str_calls_fputs_with_bytes_pointer_and_stdout` and now
asserts: bytes-GEP present, stdout-load present, both module-
preamble declarations present, and no `@puts(` call anywhere
in the emitted IR.
## Why this shape, and not the alternatives
- *Rename `io/print_str` to `io/println_str` (issue #29 option 2)*
— kept the auto-newline, just relabelled it. AILang's design
bias is explicit-over-implicit (CLAUDE.md: implicit conversions
cut). Auto-newline is a hidden runtime augmentation; the rename
would have preserved it. Rejected.
- *Append `\n` inside the polymorphic `print` (Show-mediated)
function in `examples/prelude.ail`* — would have been a one-line
fix. Rejected: `print` is the Show-mediated formatter, not a
newline emitter; baking a newline into it would have re-imposed
the same implicit-augmentation problem one layer up, breaking
callers that legitimately want pure-bytes output.
## Fixture / test sweep
30 `.ail` fixtures whose owning tests asserted line-separated
stdout now emit explicit `(do io/print_str "\n")` after each
print. Tests that asserted on multi-line stdout (`show_print_e2e`,
`floats_e2e`, `str_concat_e2e`, `eq_ord_e2e`, several `print_*`
smoke tests) had their fixtures sweetened the same way; assertions
themselves remain the canonical observable output. Fixtures that
never relied on the newline (no test ever read the absence of one)
were left untouched.
## Migrated metadata
- `crates/ailang-core/tests/hash_pin.rs`: the `ordering_match::main`
canonical hash is refreshed (`b65a7f834703ffb4` →
`8ed47b4062ce00f5`). The comment now names both successive
corpus migrations honestly: the per-type-print-retirement (which
moved `(do io/print_int x)` to `(app print x)`) AND this
fputs swap (which wrapped that with `(seq ... (do io/print_str
"\n"))`).
- `design/contracts/str-abi.md`: the consumer-ABI table now lists
`@fputs` as the print sink. A prose paragraph documents the
byte-faithful semantics and references this issue.
- `examples/ordering_match.prose.txt`: regenerated from the
updated `ordering_match.ail`.
- `crates/ail/tests/snapshots/{hello,sum,max3,list,ws_main}.ll`:
IR snapshots regenerated via `UPDATE_SNAPSHOTS=1`.
- Stale `@puts` comments in `runtime/str.c`,
`crates/ail/tests/{e2e,show_print_e2e,print_no_leak_pin}.rs`
replaced with `@fputs`.
## Verification
- `cargo test -p ail --test print_str_no_auto_newline_e2e` — both
RED tests from commit c8ecfa3 now pass.
- `cargo test --workspace` — 90 test groups GREEN, 0 failures.
- `cargo build --workspace` — GREEN.
- No new clippy lints (24 warnings pre-existing in
`crates/ailang-core/src/lib.rs:129`).
- Stats: `bench/orchestrator-stats/2026-05-21-iter-bugfix-print-
str-fputs.json` — 1/1 tasks, 0 re-loops, 0 review loops.
## Empirical evidence cited
Caught in the 2026-05-21 Qwen3-Coder naming-A/B run
(`experiments/2026-05-21-naming-ab/runs/r1/`): every cohort wrote
`(do io/print_str "...\n")` with explicit `\n` and got doubled
newlines, failing the `t3_main_prints` stdout match across all
three cohorts. The empirical LLM-natural form already assumes the
new (post-this-commit) semantics — confirming the
feature-acceptance test in CLAUDE.md.
closes #29
60 lines
2.6 KiB
Plaintext
60 lines
2.6 KiB
Plaintext
; Iter 16b.4 — LetRec captures of match-arm pattern bindings.
|
|
; `count_below(p)` takes a `Pair Int Int` (threshold, n), pattern-
|
|
; matches on `(MkPair threshold n)`, and inside that match arm runs
|
|
; a recursive helper `loop` that captures BOTH match-arm bindings
|
|
; (`threshold` and `n`) and counts how many integers in 1..=n are
|
|
; strictly less than `threshold`.
|
|
;
|
|
; The 16b.2/16b.3 desugar passes cannot lift this LetRec — both
|
|
; `threshold` and `n` are bound by a `Pattern::Ctor` Var sub-
|
|
; pattern (`ScopeEntry::MatchArm`). Before 16b.4 this panicked at
|
|
; desugar time. Now the desugar pass leaves the LetRec in place;
|
|
; the post-typecheck `lift_letrecs` pass walks the enclosing match,
|
|
; resolves each pattern binding's type via constructor-field
|
|
; substitution against the matched ctor's declared field types
|
|
; (here: `Pair Int Int`'s ctor `MkPair` has fields `[Int, Int]`,
|
|
; and the scrutinee's `Type::Con.args` are also `[Int, Int]`, so
|
|
; substitution is a no-op and both bindings get type `Int`), and
|
|
; lifts to `loop$lr_0(i: Int, threshold: Int, n: Int) -> Int`.
|
|
;
|
|
; The match has a single ctor and no catch-all; the chain machinery
|
|
; treats the only arm as default-dominating since there's no `_`
|
|
; arm needed for an exhaustive single-ctor ADT (Pair has one ctor).
|
|
;
|
|
; Expected stdout (one per line):
|
|
; count_below(MkPair 10 0) = 0
|
|
; count_below(MkPair 10 5) = 5 (1..=5 all below 10)
|
|
; count_below(MkPair 10 15) = 9 (1..=9 below 10, 10..=15 not)
|
|
|
|
(module local_rec_match_capture
|
|
|
|
(data Pair (vars a b)
|
|
(ctor MkPair a b))
|
|
|
|
(fn count_below
|
|
(doc "Match-arm captures `threshold` and `n`; inner LetRec captures both.")
|
|
(type (fn-type (params (con Pair (con Int) (con Int))) (ret (con Int))))
|
|
(params p)
|
|
(body
|
|
(match p
|
|
(case (pat-ctor MkPair threshold n)
|
|
(let-rec loop
|
|
(params i)
|
|
(type (fn-type (params (con Int)) (ret (con Int))))
|
|
(body
|
|
(if (app gt i n)
|
|
0
|
|
(if (app lt 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 MkPair 10 {0,5,15}. Expected: 0, 5, 9.")
|
|
(type (fn-type (params) (ret (con Unit)) (effects IO)))
|
|
(params)
|
|
(body
|
|
(seq (seq (app print (app count_below (term-ctor Pair MkPair 10 0))) (do io/print_str "\n"))
|
|
(seq (seq (app print (app count_below (term-ctor Pair MkPair 10 5))) (do io/print_str "\n"))
|
|
(seq (app print (app count_below (term-ctor Pair MkPair 10 15))) (do io/print_str "\n")))))))
|