navigation_safety_enums #

Pure Dart navigation-safety domain enums. Five stable enum types extracted from navigation_safety_core for consumers who need the safety vocabulary without paying for the larger core-package surface area or its transitive dependencies.

• AlertSeverity — info / warning / critical, with declaration- order-load-bearing severity comparison via .index.
• CircadianPhase — 24-hour partition for circadian-aware threshold tuning, with a caution-add-only multiplier extension and a circadianPhaseFromHour(int) helper.
• DriverState — live driver-state axis (alert / fatigued / distracted / impairedVisibility), orthogonal to driver-trait.
• DriverProfile — driver-class trait axis (ageingRural / snowZoneExperienced / noviceUrban / professional / agriculturalForestry / foreignTouristSnowZone).
• HapticCuePattern — tactile (vibration) hazard-cue grammar for the accessibility channel (none / warning / critical). Carries the same warning set as the audio channel off the same severity gate — so a deaf / hard-of-hearing driver, or any driver inside a roaring-wind whiteout where speech cannot carry, is never silently dropped from the most serious warnings. The two announced tiers render as distinct cues (pulseCount 2 vs 3) so they can be told apart by feel alone. Map from AlertSeverity via hapticCueForSeverity(severity); the cue is a pure function of severity only.

No Flutter dependency. No transitive dependencies (beyond test + lints for development). Safe to consume from CLI tools, server-side logic, test fixtures, and any other pure-Dart package that needs the safety vocabulary.

Install #

Add to pubspec.yaml:

dependencies:
  navigation_safety_enums: ^0.1.0

Then import the barrel:

import 'package:navigation_safety_enums/navigation_safety_enums.dart';

Example #

import 'package:navigation_safety_enums/navigation_safety_enums.dart';

void main() {
  // Severity ordering is declaration-order-load-bearing.
  assert(AlertSeverity.critical.index > AlertSeverity.warning.index);
  assert(AlertSeverity.warning.index > AlertSeverity.info.index);

  // Map a 24-hour clock hour to a circadian phase.
  final phase = circadianPhaseFromHour(DateTime.now().hour);
  print('phase=${phase.name} multiplier=${phase.multiplier}');

  // Driver state and driver profile are orthogonal axes.
  const profile = DriverProfile.foreignTouristSnowZone;
  const state = DriverState.fatigued;
  print('profile=${profile.name} state=${state.name}');
}

Relationship to navigation_safety_core #

Four of the five enum source files (AlertSeverity, CircadianPhase, DriverState, DriverProfile) are byte-identical to the corresponding files in navigation_safety_core 0.10.0 at the time of extraction. HapticCuePattern was added later (0.1.3) and has no counterpart in that 0.10.0 baseline. A subsequent navigation_safety_core 0.11.0 release will depend-on and re-export from this package for ABI-compat, so existing consumers of navigation_safety_core will not need to change imports.

This package is intended for two cohorts who consume the enum vocabulary directly:

• open-source-consumers — pure-Dart packages and CLI tools that need the vocabulary without the larger core-package surface area.
• parallel-product-builders — integrators building independent navigation or driver-assist products who want a stable shared vocabulary without coupling their dependency tree to the full navigation_safety_core evolution.

Caveats — UNVERIFIED magnitudes #

The numeric multiplier values on CircadianPhase are design-default hypotheses pending field-measurement validation. See the in-source documentation and navigation_safety_core's KNOWN_LIMITATIONS.md for the UNVERIFIED-magnitude flag.

The state-axis adjustment magnitudes documented on DriverState values are similarly UNVERIFIED at this spike. Both axes carry the caution-add-only invariant — values may make thresholds warn earlier than baseline but never later.

License #

BSD-3-Clause. See LICENSE.