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
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58 lines
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; Iter 16b.6 — LetRec inside a polymorphic enclosing fn.
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; `apply_n_times : Forall(a). Fn(Int, a, Fn(a) -> a) -> a`
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; applies `f` to `x` exactly `n` times. The recursive helper `loop`
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; captures `f` from the enclosing fn's params — `f`'s declared type
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; is `Fn(a) -> a`, which mentions the outer fn's type var `a`. The
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; 16b.6 lift produces a synthetic top-level fn
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; `loop$lr_0 : Forall(a). Fn(Int, a, Fn(a) -> a) -> a`
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; and rewrites `(app loop k acc)` → `(app loop$lr_0 k acc f)`.
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;
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; `main` drives `apply_n_times` at TWO distinct type instantiations
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; so codegen's monomorphisation queue picks up `loop$lr_0` twice
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; (once at `a = Int` to compute `succ` applied 5x to 0 → 5; once at
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; `a = Bool` to compute `not` applied 4x to false → false). This
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; exercises the substitution of the outer Forall.vars into both the
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; original LetRec params and the appended capture types.
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;
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; Expected stdout (one per line): 5, false.
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(module poly_rec_capture
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(fn succ
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(doc "Helper: increment Int. Used as the Fn(Int) -> Int instance.")
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(type (fn-type (params (con Int)) (ret (con Int))))
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(params x)
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(body (app + x 1)))
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(fn flip
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(doc "Helper: boolean negation as a top-level fn (so it has an adapter for value-position).")
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(type (fn-type (params (con Bool)) (ret (con Bool))))
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(params b)
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(body (app not b)))
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(fn apply_n_times
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(doc "Apply f to x exactly n times. Polymorphic in a.")
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(type
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(forall (vars a)
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(fn-type
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(params (con Int) a (fn-type (params a) (ret a)))
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(ret a))))
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(params n x f)
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(body
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(let-rec loop
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(params k acc)
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(type (fn-type (params (con Int) a) (ret a)))
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(body
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(if (app eq k 0)
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acc
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(app loop (app - k 1) (app f acc))))
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(in (app loop n x)))))
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(fn main
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(doc "Drive apply_n_times at Int (succ 5 times from 0) and Bool (not 4 times from false).")
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(type (fn-type (params) (ret (con Unit)) (effects IO)))
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(params)
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(body
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(seq (seq (app print (app apply_n_times 5 0 succ)) (do io/print_str "\n"))
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(seq (app print (app apply_n_times 4 false flip)) (do io/print_str "\n"))))))
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