v4.0.0

Breaking changes

• Minimum Node.js version raised from >=18 to >=22. Node 18 and 20
  are both EOL; 22 is the oldest line still in maintenance. Consumers on
  Node 18/20 should stay on 3.x.
• OutputFnType and StreamScheme are now const objects instead of
  enums. Both are still exported as a value and as a type, so
  StreamScheme.MCG, StreamScheme['MCG'], and streamScheme: StreamScheme
  all keep working. What no longer works is the enum reverse mapping
  (StreamScheme[0] === 'SETSEQ'), and the types are now unions of their
  numeric literals rather than nominal enum types, so plain numbers are
  accepted where an enum member was previously required.

Changed

• randomInt on an MCG state of 0, a fixed point whose output is always 0,
  now throws a RangeError (maximum call stack size exceeded) instead of
  never returning.

Performance

• The hot path is 1.2–3× faster, with no change to the API, its
  immutable semantics, or any output. Measured against the previous build
  on the same machine, Node 22 at the low end of each range and Chromium 153
  at the high end: randomInt 1.2–2×, nextState 1.5–2×, randomList
  1.1–1.35×, createPcg32 3.5–5×, stepState 2.5–3×, and prevState
  about 150×. mulberry32 and sfc32 draws are 1.5–3× faster and createSfc32
  about 9×. The new build was compared with the published 3.0.0 on 13.7
  million cases across every output function, stream scheme, seed shape,
  and randomInt bound, including the rare 64-bit carry.
  • One LCG step is written out in place, so nextState allocates only the
    state it returns and no intermediate Uint64 objects. Dispatch on the
    variant and the output function is a switch to known functions rather
    than a table lookup, so each call site stays monomorphic.
  • prevState multiplies by the inverse of the multiplier mod 2^64 instead
    of running the 64-round jump-ahead for a delta of −1.
  • stepState keeps Brown's jump-ahead in local halves and allocates
    nothing per round.
  • randomInt computes the rejection threshold only for a draw below the
    bound, the only draw that can be rejected, and replaces % with a
    floor-multiply-subtract for integer bounds, which avoids V8's slow float
    modulo for draws at or above 2^31.
  • createPcg32 seeds number inputs without BigInt.
• One measured loss: getOutput called on its own is about 20% slower (a
  few nanoseconds per call), because the switch dispatch is a little more
  code than a table lookup. The switch stays because a table turns into one
  polymorphic call site as soon as a process uses more than one variant,
  which made mulberry32 and sfc32 draws 35–50% slower in the old code.

Tooling

• Upgraded to TypeScript 7, the native compiler. Type checking now runs as
  its own npm run typecheck step in CI.
• Replaced tsup with tsdown (rolldown) for the dual ESM/CJS build.
  Output filenames are unchanged.
• Replaced eslint / typescript-eslint with oxlint, configured in
  .oxlintrc.json.
• The source is now erasableSyntaxOnly, verbatimModuleSyntax, and
  isolatedModules clean, and type checks with noUncheckedIndexedAccess.
• Bumped @types/node to ^26 and rebased tsconfig.json on
  @tsconfig/node22.
• CI matrix moved to Node 22/24/26.