agent: builder model: opus max_turns: 110 budget_usd: 28 —
scalar::from(n) with a precondition; an integer as scalar is refused (the owner’s decision 2026-10-30; blocks yaml’s escapes, #928)A compiler, std and Part I change inside the yaml lane. It changes crates/, so the gate of .claude/agents/builder.md applies in full (a change to tools/check_*.nika or tools/emit_*.nika also runs target/fast/nikaia test --both-settings --project tests/compiler); it raises the toolchain version (the supervisor’s: write the Changelog: line, touch no version line), and target/fast/nikaia test --project packages/yaml and --project packages/json stay green.
scalar::from(n) -> scalar (n: i64; narrower integers widen into it, Part I 2.2) with a precondition, not an optional result: n is not a surrogate (0xD800..=0xDFFF) and not above 0x10FFFF (and not negative). It is held as any precondition is (ADR-269 D5, D20; ADR-380): proved at a call where the caller’s facts prove it; where not proved, refused under unproved-claims = "error" (the default, NK1300) or checked at run time under "warn"; --asserts lists it. Write it as a std function whose assert publishes the precondition in crates/nikaia-std/std.contracts (requires), the way ADR-269 §5 says std carries its own.n as scalar from any integer type other than u8 is refused by the checker, with a help naming scalar::from. Use NK1241 (an as that can lose a value; Part I: “the program says by name what it means”); if it does not fit, ask under Needs: for a code, do not invent one. b as scalar from a u8 always fits and stays.as scalar is a run-time checked cast (FactNarrowing::ToScalar: crates/nikaia-std/src/tools/check_reads.nika ~441, check_facts.nika ~54, emit_core_places.nika ~489; test tests/compiler/tests/an_integer_cast_as_scalar_is_checked.nika), and a literal (8232 as scalar) skips that path and reaches rustc (#1003’s probe). Both give way to the refusal.scalar::from and its spec text. The function in std (find where an associated function on a built-in type lives, e.g. how i64::MAX or a text function is reached; if scalar::from cannot be named as written, that is a Found: with a probe, not another name), its requires in std.contracts, Part I: the scalar bullet of 2.2 (docs/specification/10-nikaia-light.md ~276) and the as paragraph (~450, “A conversion is written as where it always fits”) say how an integer becomes a scalar. New test tests/compiler/tests/scalar_from_a_proved_code_point.nika (+ .stdout): a literal, a value after if n >= 0 && n <= 0x10FFFF && (n < 0xD800 || n > 0xDFFF), and one through assert; with --asserts showing them proved if the test harness can show it, else in a comment.as scalar from a wider integer in the repository moves to scalar::from or a literal (8 as scalar is '\u{8}'). Known sites: packages/json/src/main.nika 88, 196, 206, 208 (196 decodes \u: its surrogate checks above should prove the precondition; if hex4’s range is not known to the prover, an assert stating it where it is proved is fine, a run-time check written around the prover is not: stop with Found:), scripts/grammar_arrow.nika 25, crates/rs2nika/convert/src/tr_expr.nika 459 (the converter writes scalar::from(x) for a Rust char::from_u32(..).unwrap()-like cast that is not from u8), tests/compiler/tests/an_integer_cast_as_scalar_is_checked.nika (rewrite it onto scalar::from, or replace it by step 1’s test and delete it). grep -rn "as scalar" --include=*.nika for the rest; x as u8 as scalar stays.u8 as scalar (variable and literal alike) with the help; the ToScalar run-time path goes; the lowered crates/nikaia-std/src/tools/lowered/*.rs regenerate (lower-std, docs/builder-facts.md). Test tests/compiler/tests/an_integer_as_scalar_is_refused.nika + .stderr (an i64 variable and the literal 8232). Commit message Fixes #1003.The new tests pass at both settings; packages/json and packages/yaml tests green; the gate is green; Fixes #1003 in the last commit; Changelog: one sentence for the version heading (the language changed: scalar::from, as scalar refused).
docs/builder-facts.md first. develop in the main checkout; git status at start: other agents’ uncommitted files are not yours, never touch or stage them.git add <files> only; commit after each step; git push origin develop fast-forward, no rebase (rejected: report Pushed: rejected, go on committing).cargo fmt, cargo clippy --all-targets -- -D warnings, scripts/pre-push-check.sh, and the gate of .claude/agents/builder.md (#852).CHANGELOG.md, badges; no new NK code. New tests in Nikaia only; never the full suite. No foreground sleep, no polling; scripts in files.std or the toolchain lacks stops the work: no code around it unless an ADR or Part I-III refuses it (name it). Else Result: blocked, Found: gap + probe, Needs: owner decision (CLAUDE.md, A missing form stops the work).NIKAIA_CACHE_LIMIT=2G; at most two clones with target/ in the machine; delete your own clone’s target/ and target/release/nikaia-scratch at the end; report GB freed.Pushed: line names the pushed sha. A report without a Pushed: line, or with a placeholder left in (TC, DISK), is not done and cuts the batch (k3a1 2026-10-29: Result: done, nothing committed).NIKAIA_CACHE_LIMIT=2G target/fast/nikaia test --project packages/yaml green, and cargo test --profile fast -p nikaia --test it -- fmt::every_nika_file (it formats every .nika under packages/). For a change only under packages/yaml/ this is the gate the line above asks for; a change under crates/ runs the gate of .claude/agents/builder.md (#852) as well. target/fast/nikaia is built by the session hook; if it is missing, cargo build --profile fast -p nikaia once.Changelog: none, unless the brief changes crates/.packages/yaml/ and the brief’s own report, unless the brief names it; never docs/briefs/batch.txt or a brief of another lane./home/user/Nikaia/docs/briefs/yaml/y4-1003-scalar-from.md.report.md)Fields of docs/architect.md, Briefs and reports: Result: done|noop|partial|blocked (the bare word alone on that line: Result: done, never a summary after it, which cuts the batch, b869a 2026-10-27; Owner: is a question for the owner or none, never a role), Files, Commit, Body (optional, one paragraph for the commit message), Fixes, Pushed, Tests, Gate (green|red), Deviation, Found, Needs, Changelog, Owner, Disk freed, and for a move Rs2nika: (the kept N of M lines of rs2nika --score, then the three costliest hand edits; none for a task that moves no Rust, none (redesign) for a brief with Shape: redesign and no Convert: line). none where nothing, and then the bare word: Deviation: none (a note) cuts the batch (batch.nika compares exactly); a note goes into the commit message. Found: is only for a defect outside your change (it cuts the batch); a process event such as another session resetting or rewriting your files is no Found:, it goes under Needs: (m3a 2026-10-28); a converter draft that came out wrong is no Found:, it is one of the costliest edits under Rs2nika:, which the converter lane reads (e12-4b 2026-10-27); how you solved your own step goes into the commit message. Deviation: is only a step of the brief built otherwise than written or not built (a choice the brief left to you, such as keep what X needs and say so, is no deviation: it goes into the commit message; nor is building two steps in one commit when every step is built, e12-3a 2026-10-27, nor a step another commit on develop already built, shown by your test failing with that commit’s change reverted, b889 2026-10-27: name the commit in Body:, nor a test’s expected .stdout/.stderr taken from what the program really prints where the brief’s sketch of it was short or wrong, b934 2026-10-29: say so in Body:, nor a lowering that follows the ADR governing it where the brief’s expected lowering contradicts that ADR, b933 2026-10-29: name the ADR in Body:, nor re-keying an allow-list entry (KNOWN) whose hash changed for the same program and the same reason, b-fixforward-sweep2 2026-10-28: say so in Body:); how you verified (e.g. a test not run against the unfixed compiler) goes under Tests:. A noop says why under Tests: (what was probed), not under Deviation:. Final answer, one line: done <sha>, report <path> (or BLOCKED: ... / PUSH REJECTED ...).
Attribution: Co-Authored-By: Claude Opus 5.5 noreply@anthropic.com Claude-Session: https://claude.ai/code/session_01UVxJDveRM5qKZKyCqq6Y24