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
58 lines
2.1 KiB
Plaintext
58 lines
2.1 KiB
Plaintext
; Iter 17a — first fixture exercising the per-fn arena (alloca for
|
|
; non-escaping allocations).
|
|
;
|
|
; `peek` builds a Box(n) and immediately matches on it, returning
|
|
; a literal Int that does not depend on the box's payload. The
|
|
; box's value is fully consumed by the local match — it never
|
|
; flows to a fn arg, never becomes a ctor field, never returns.
|
|
; Iter 17a's escape analysis flags the `(term-ctor Box MkBox n)`
|
|
; allocation as non-escaping; codegen lowers it to LLVM `alloca`
|
|
; instead of the runtime allocator. The heap is not touched at
|
|
; all by this fn.
|
|
;
|
|
; `count` repeats the same pattern under recursion: each call to
|
|
; `count` builds a fresh Box(_), matches it, and returns either 0
|
|
; or 1 + (count rest). Without the alloca optimisation each
|
|
; recursive frame allocates a Box on the heap; with the
|
|
; optimisation, each frame's Box dies with its frame.
|
|
;
|
|
; Expected stdout (one per line):
|
|
; 42 — peek(0) returns the literal 42 from the only arm
|
|
; 42 — peek(123) ditto (the input value never reaches stdout)
|
|
; 5 — count(5)
|
|
; 0 — count(0)
|
|
|
|
(module escape_local_demo
|
|
|
|
(data Box (vars a)
|
|
(ctor MkBox a))
|
|
|
|
(fn peek
|
|
(doc "Build a Box(n), discard the payload, return 42. The Box is non-escaping.")
|
|
(type (fn-type (params (con Int)) (ret (con Int))))
|
|
(params n)
|
|
(body
|
|
(let b (term-ctor Box MkBox n)
|
|
(match b
|
|
(case (pat-ctor MkBox _) 42)))))
|
|
|
|
(fn count
|
|
(doc "Recurse n times; each call builds a temporary Box, discards its payload via _, and returns 0 if n<=0, else 1 + count(n-1).")
|
|
(type (fn-type (params (con Int)) (ret (con Int))))
|
|
(params n)
|
|
(body
|
|
(if (app le n 0)
|
|
0
|
|
(let b (term-ctor Box MkBox n)
|
|
(match b
|
|
(case (pat-ctor MkBox _) (app + 1 (app count (app - n 1)))))))))
|
|
|
|
(fn main
|
|
(type (fn-type (params) (ret (con Unit)) (effects IO)))
|
|
(params)
|
|
(body
|
|
(seq (seq (app print (app peek 0)) (do io/print_str "\n"))
|
|
(seq (seq (app print (app peek 123)) (do io/print_str "\n"))
|
|
(seq (seq (app print (app count 5)) (do io/print_str "\n"))
|
|
(seq (app print (app count 0)) (do io/print_str "\n"))))))))
|