Commit Graph

2 Commits

Author SHA1 Message Date
Brummel 26fb3459d8 GREEN: io/print_str byte-faithful via @fputs(@stdout) — closes #29
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
2026-05-21 12:22:45 +02:00
Brummel 7a42989b34 iter nullary-app.1 (DONE 5/5): accept (app f) as canonical zero-arg call
Resolves Gitea #12 — the design fork from the 2026-05-20 /boss
session, surfaced independently by two prior fieldtests
(mut-local F3 + loop-recur `run_forever`).

Mechanics, layer by layer:

  Parser — `crates/ailang-surface/src/parse.rs:1322-1331` drops
    the 4-line `expected at least one argument` guard in
    `parse_app_body`. Grammar comments at file top change `term+`
    to `term*` on both `app-term` and `tail-app-term`; doc comment
    on `parse_app_body` changes `1+ args` to `0+ args`. Inline
    comment cites #12 and notes which layers below already accept
    empty args.

  Serde — `crates/ailang-core/src/ast.rs:419-425` annotates
    `Term::App.args` with `#[serde(default)]`, mirroring
    `Term::Ctor.args`'s *actual* attrs verbatim (no
    `skip_serializing_if`). Write behaviour unchanged — canonical
    JSON still emits `"args":[]` for nullary calls; only read
    behaviour gains tolerance for the `args` key being absent.
    Verified hash-impact-free at plan time:
    `grep -rn '"args":\[\]' examples/*.ail.json` returns zero
    matches, so no existing fixture's canonical bytes shift.

  Doc-honesty — `design/contracts/data-model.md`:
    (a) the `app` jsonc shape gains an explicit "args may be
        empty / read-tolerant" note;
    (b) the existing `ctor` comment claiming "args omitted when
        empty" was factually false (Ctor.args has no
        `skip_serializing_if`; a serde probe at plan time
        confirmed writes always emit `"args":[]`). Rewritten to
        describe the actual write/read asymmetry, with a
        cross-reference to the new `app` note.

  E2E pin — `crates/ail/tests/nullary_app_e2e.rs` +
    `examples/nullary_app_smoke.ail`. Defines `greet : fn()
    -> Unit !IO` and calls it as `(app greet)`; asserts stdout
    `"hello\n"`. RED→GREEN pin for the parser change AND the
    milestone-protecting E2E for nullary call surface going
    forward. Fixture literal is `"hello"` (no `\n`) because
    `io/print_str` lowers via `puts` which appends a newline —
    the plan body had a `"hello\n"` literal which would have
    yielded `"hello\n\n"`; the implementer caught and aligned to
    the canonical pattern in `examples/hello.ail` while writing
    the fixture, fix scoped to that single file.

Layers below parser untouched: typechecker's arity check at
`crates/ailang-check/src/lib.rs:3300` is `args.len() !=
params.len()` which is `0 != 0 → false` for nullary; codegen's
`args.iter().zip(sig.params.iter())` at
`crates/ailang-codegen/src/lib.rs:2410` is an empty loop;
LLVM `call @ail_<mod>_<name>()` with empty arglist is valid;
surface printer's arg-emit loop at
`crates/ailang-surface/src/print.rs:430-434` writes nothing for
empty args, producing exactly `(app f)`.

Verification: full workspace `cargo test --workspace --quiet`
green (0 failed across all crates); drift pins
`design_index_pin 5/5` + `design_schema_drift 8/8`; round-trip
`2/2`; new `nullary_app_e2e 1/1`. Stats file:
`bench/orchestrator-stats/2026-05-20-iter-nullary-app.1.json`.

closes #12
2026-05-20 18:57:14 +02:00