feat: Add listContains and firstWhereOrNull

lib/automaton.dart

@@ -1,99 +0,0 @@
-class NoTransitionPossibleException implements Exception {
-  @override
-  String errMsg() => "The transition graph allows no transition";
-}
-
-/// A deterministic finite automaton. [T] is the state type while
-/// [I] is the input type.
-/// Edges of the node must be added with [addTransition]. If a trap state
-/// is required, it can be set in the constructor.
-class DeterministicFiniteAutomaton<T, I> {
-  /// The current state of the DFA
-  T _state;
-  /// The edges of the DFA: State x Input -> State
-  Map<T, Map<I, T>> _transitions;
-  /// Trap state 
-  T? trapState;
-
-  /// The argument is the initial state
-  DeterministicFiniteAutomaton(this._state, { this.trapState }) : _transitions = {};
-
-  T get state => _state;
-
-  void addTransition(T oldState, I input, T newState) {
-    assert(oldState != trapState);
-    // These are handled implicitly if no transition has been found
-    assert(newState != trapState);
-
-    if (!_transitions.containsKey(oldState)) {
-      _transitions[oldState] = {};
-    }
-
-    _transitions[oldState]![input] = newState;
-  }
-
-  /// Transition the DFA based on its current state and the input [input].
-  void onInput(I input) {
-    final newState = _transitions[_state]?[input];
-    if (newState == null) {
-      // Go to the trap state if we can
-      if (trapState != null) {
-        _state = trapState!;
-        return;
-      } else {
-        throw NoTransitionPossibleException();
-      }
-    }
-
-    _state = newState;
-  }
-
-  /// Returns where [input] would take the automaton to. Returns null if no transition
-  /// is possible, ignoring trap transitions.
-  T? peekTransition(I input) {
-    if (!_transitions.containsKey(_state) || !_transitions[_state]!.containsKey(input)) {
-      return null;
-    }
-
-    return _transitions[_state]![input]!;
-  }
-}
-
-typedef MealyAutomatonCallback<T, I> = void Function(T oldState, I input);
-class MealyAutomaton<T, I> {
-  /// The base automaton
-  final DeterministicFiniteAutomaton<T, I> _automaton;
-  /// Mapping of State x Input -> Output callback
-  Map<T, Map<I, MealyAutomatonCallback<T, I>>> _outputs;
-  /// Trap state
-  MealyAutomatonCallback<T, I>? trapCallback;
-
-  // TODO: Assert that trapState != null implies trapCallback != null.
-  MealyAutomaton(T initialState, { T? trapState, this.trapCallback })
-    : _outputs = {},
-      _automaton = DeterministicFiniteAutomaton(initialState, trapState: trapState);
-
-  T get state => _automaton.state;
-      
-  void addTransition(T oldState, I input, T newState, MealyAutomatonCallback<T, I> callback) {
-    _automaton.addTransition(oldState, input, newState);
-
-    if (!_outputs.containsKey(oldState)) {
-      _outputs[oldState] = {};
-    }
-
-    _outputs[oldState]![input] = callback;
-  }
-
-  void onInput(I input) {
-    final _state = _automaton.state;
-    if (_automaton.peekTransition(input) == null && trapCallback == null) {
-      throw new NoTransitionPossibleException();
-    }
-
-    final callback = _outputs[_state]?[input] ?? trapCallback!;
-
-    _automaton.onInput(input);
-    callback(_state, input);
-  }
-}

lib/awaitabledatasender.dart

@@ -72,6 +72,7 @@ abstract class AwaitableDataSender<
   /// Future will be returned that can be used to await a response. If it
   /// is false, then null will be imediately resolved.
   Future<R?> sendData(S data, { bool awaitable = true, @visibleForTesting String? id }) async {
+    // ignore: no_leading_underscores_for_local_identifiers
     final _id = id ?? _uuid.v4();
     Future<R?> future = Future.value(null);
     _log.fine("sendData: Waiting to acquire lock...");

lib/lists.dart

@@ -0,0 +1,16 @@
+/// A wrapper around List<T>.firstWhere that does not throw but instead just
+/// returns true if [test] returns true for an element or false if [test] never
+/// returned true.
+bool listContains<T>(List<T> list, bool Function(T element) test) {
+  return firstWhereOrNull<T>(list, test) != null;
+}
+
+/// A wrapper around [List<T>.firstWhere] that does not throw but instead just
+/// return null if [test] never returned true
+T? firstWhereOrNull<T>(List<T> list, bool Function(T element) test) {
+  try {
+    return list.firstWhere(test);
+  } catch(e) {
+    return null;
+  }
+}

lib/moxlib.dart

@@ -1,5 +1,5 @@
 library moxlib;
 
 export "awaitabledatasender.dart";
-export "automaton.dart";
+export "lists.dart";
 export "math.dart";

test/automaton_test.dart

@@ -1,79 +0,0 @@
-import "package:moxlib/automaton.dart";
-
-import "package:test/test.dart";
-
-enum States {
-  a, b, c, trap
-}
-
-void main() {
-  test("Test a simple DFA", () {
-      final automaton = DeterministicFiniteAutomaton<States, int>(States.a);
-      automaton.addTransition(States.a, 1, States.b);
-      automaton.addTransition(States.b, 2, States.c);
-      automaton.addTransition(States.c, 3, States.a);
-
-      expect(automaton.state, States.a);
-      automaton.onInput(1);
-      expect(automaton.state, States.b);
-      automaton.onInput(2);
-      expect(automaton.state, States.c);
-      automaton.onInput(3);
-      expect(automaton.state, States.a);
-  });
-
-  test("Test a simple DFA with a trap state", () { 
-      final automaton = DeterministicFiniteAutomaton<States, int>(States.a, trapState: States.trap);
-      automaton.addTransition(States.a, 1, States.b);
-      automaton.addTransition(States.b, 2, States.c);
-      automaton.addTransition(States.c, 3, States.a);
-
-      expect(automaton.state, States.a);
-      automaton.onInput(1);
-      expect(automaton.state, States.b);
-      automaton.onInput(2);
-      expect(automaton.state, States.c);
-      automaton.onInput(4);
-      expect(automaton.state, States.trap);
-
-      // Transitioning away from the trap state should not be possible
-      automaton.onInput(5);
-      expect(automaton.state, States.trap);
-  });
-
-  test("Test a simple Mealy Automaton", () {
-      bool called = false;
-      final callback = (state, input) {
-        called = true;
-      };
-      final automaton = MealyAutomaton<States, int>(States.a);
-
-      automaton.addTransition(States.a, 1, States.b, callback);
-
-      automaton.onInput(1);
-
-      expect(automaton.state, States.b);
-      expect(called, true);
-  });
-
-  test("Test a simple Mealy Automaton with a trap state", () {
-      bool called = false;
-      bool trapCalled = false;
-      final callback = (state, input) {
-        called = true;
-      };
-      final trapCallback = (state, input) {
-        trapCalled = true;
-      };
-      final automaton = MealyAutomaton<States, int>(States.a, trapState: States.trap, trapCallback: trapCallback);
-
-      automaton.addTransition(States.a, 1, States.b, callback);
-
-      automaton.onInput(1);
-      expect(called, true);
-
-      automaton.onInput(1);
-      expect(automaton.state, States.trap);
-      expect(trapCalled, true);
-  });
-}