Changelog

All notable changes to Spindle-Rust are documented here. For the full changelog with migration notes, see CHANGELOG.md in the repository root.

v0.3.0 (2026-03-04)

SPEC-017 Arithmetic Module: full arithmetic expression support in rule bodies.
- Three numeric term types: Integer, Decimal (arbitrary-precision via rust_decimal), Float (FiniteFloat wrapper rejecting NaN/Inf).
- Automatic type promotion chain: Integer -> Decimal -> Float.
- ArithExpr AST with n-ary ops (+, -, *, /, min, max), binary ops (div, rem, **), and unary ops (abs).
- bind variable binding and comparison guards (=, !=, <, >, <=, >=) in rule bodies.
- Cross-type numeric matching in grounding (e.g., Integer(2) matches Decimal(2.0)).
- SPL parser extended with arithmetic expression, numeric literal, and guard parsing.
- Parse-time rejection of arithmetic in heads, negated arithmetic, and reserved keywords.
SPEC-018 Temporal Atom Identity: atoms with different temporal bounds are now treated as distinct during reasoning.
- Synthetic bridging rules connect temporally-scoped variants.
- Core query operators (what_if, why_not, requires) upgraded to temporal-aware matching.
v2 JSON output (REQ-012): --v2 CLI flag and reasonV2 WASM method emitting typed Term arguments in schema spindle.reason.v2.

Breaking: From<NumericValue> for Term replaced with TryFrom; non-finite floats now return errors.
Literal::predicate_ids and Substitution::terms migrated from SymbolId to Term.
RuleBody migrated from SmallVec<[Literal; 4]> to SmallVec<[BodyLiteral; 4]>.

FiniteFloat serde deserialization validates invariants, preventing non-canonical or non-finite values.
SPL round-trip for arithmetic expressions preserved correctly.
Tilde-negated reserved keywords (~>, ~bind, etc.) rejected in list-form literals.
Negative base with fractional exponent rejected in decimal_pow.
Temporal bounds preserved in body normalization.

IMPL-011 Verified requires: requires command now verifies abduction solutions by default.
- New core API: requires_with_options(theory, goal, options) with RequiresOptions, RequiresResult, RequiresSearchStatus, RequiresVerificationStats.
- New CLI contract schema: spindle.requires.v2.
Release tooling: release.sh script with pre-flight validation checks and make release target.
Pre-1.0 semver policy documented.

requires --json emits spindle.requires.v2 schema only.
spindle capabilities --json advertises schemas.requires = spindle.requires.v2.
Core requires() compatibility wrapper delegates to verified logic.

Eliminated false-positive requires candidates that fail under full defeasible reasoning.
Corrected BudgetExhausted classification for duplicate raw-candidate edge cases.
Defensive collision handling for injected verification fact labels.