Result: done
Files: crates/nikaia-std/src/tools/keeps.nika crates/nikaia-std/src/tools/lowered/keeps.rs tests/compiler/tests/a_returned_lambda_keeps_its_fn_parameter.nika tests/compiler/tests/a_returned_lambda_keeps_its_fn_parameter.stdout
Commit: keeps: a lambda handed out keeps the fn parameters it names (#1034)
Body: hand_over (a return, an assignment, a body’s last value) and the struct, list and tuple literal fields now also keep every parameter a lambda among them names (keeps_named_by_a_lambda, holes_of threaded through hand_over). Rows a and b, and the twice function of row c, lower and run. Row c’s caller side has a second cause and is left out of the test: a let-bound local lambda handed to a kept parameter (let add = fn(x) { x + 3 } then keep(add), even with fn keep(f) { return f }) reaches rustc as a bare closure where Kept<dyn Fn> is expected, and a use of add after that is NK1245; both happen on the unfixed compiler too. So twice takes an inline lambda in the test, which prints 3, 7, 7.
Part: #1034
Tests: new test passes (nikaia run, nikaia test –both-settings) and failed on the unfixed binary (rustc at lines 6, 10, 14); a_kept_lambda_calls_a_captured_fn and a_kept_fn_copied_from_a_name_or_field pass; fn apply(f, x) { return f(x) } still lowers f: &impl AsyncFn(i64) -> i64; it guard set + keeps filter 156 passed; clippy clean; pre-push-check ok; lower-std fixpoint clean; tests/compiler –both-settings 424 passed, 6 failed, none mine: 5 found target/fast/nikaia missing mid-run (another agent rebuilding), 1 another agent’s untracked a_bit_operation_in_a_head_wants_parentheses
Gate: green
Deviation: row c left out of the test (second cause, see Found); Part: #1034 instead of Fixes
Found: a let-bound local lambda handed to a kept fn parameter fails in rustc (probe: fn keep(f: fn(i64) -> i64) -> fn(i64) -> i64 { return f } fn main() { let add = fn(x) { x + 3 }; let t = keep(add); println(f"{t(1)}") } gives Mismatched types at let t = keep(add): expected Kept<dyn Fn(i64) -> Pin<Box<dyn Future>>>, found closure); adding println(f"{add(1)}") after it is NK1245 at check; also fn mk(k: i64) -> fn(i64) -> i64 { let g = fn(x) { x + k }; return g } is rustc Mismatched types at return g; all on the unfixed compiler
Needs: none
Changelog: A function that hands out a lambda capturing one of its fn parameters (returned, assigned, or put in a struct, list or tuple) keeps that parameter, instead of a lowering rustc refused.
Owner: none
Disk freed: 0.04 GB (two binary copies in the scratchpad); cache 3.3G, disk 6.7G free; new cache entries over 100 MB: rlib/af187e66 265M, run-bundle/2df20709 286M, build-time-parsers/768d2772 1026M, build-time-bundle/b95bc86d 484M
Rs2nika: none
Pushed: 650a4ef486524e982d512800b3175715281024b9
