add: nfa2dfa算法

CanonSharp.Tests/LexicalAnalyzerTests/RegularExpressionTests.cs

@@ -0,0 +1,77 @@
+using CanonSharp.Common.LexicalAnalyzer;
+
+namespace CanonSharp.Tests.LexicalAnalyzerTests;
+
+public class RegularExpressionTests
+{
+    [Fact]
+    public void KleeneTest()
+    {
+        RegularExpression expression = RegularExpression.Concatenate(
+            RegularExpression.Kleene(RegularExpression.Single('a')),
+            RegularExpression.Single('b'));
+
+        NondeterministicFiniteAutomation automation = expression.Convert2Nfa();
+
+        automation.Start.Transactions.TryGetValue(EmptyChar.Empty, out HashSet<NondeterministicState>? next);
+        Assert.NotNull(next);
+
+        Assert.Contains(next, s => s.Transactions.ContainsKey(new EmptyChar('a')));
+        Assert.Contains(next, s => s.Transactions.ContainsKey(new EmptyChar('b')));
+    }
+
+    [Fact]
+    public void AlternateTest()
+    {
+        RegularExpression expression = RegularExpression.Alternate(
+            RegularExpression.Kleene(RegularExpression.Single('a')),
+            RegularExpression.Single('b'));
+
+        NondeterministicFiniteAutomation automation = expression.Convert2Nfa();
+
+        automation.Start.Transactions.TryGetValue(EmptyChar.Empty, out HashSet<NondeterministicState>? next);
+        Assert.NotNull(next);
+
+        Assert.Contains(next, s => s.Transactions.ContainsKey(new EmptyChar('b')));
+
+        NondeterministicState? state = (from item in next
+            where item.Transactions[EmptyChar.Empty].Count == 2
+            select item).FirstOrDefault();
+        Assert.NotNull(state);
+
+        Assert.Contains(state.Transactions[EmptyChar.Empty],
+            s => s.Transactions.ContainsKey(new EmptyChar('a')));
+    }
+
+    [Fact]
+    public void ConvertTest()
+    {
+        RegularExpression expression = RegularExpression.Alternate(
+            RegularExpression.Kleene(RegularExpression.Single('a')),
+            RegularExpression.Single('b'));
+
+        NondeterministicFiniteAutomation automation = expression.Convert2Nfa();
+        DeterministicFiniteAutomation dfa = DeterministicFiniteAutomation.Create(automation);
+
+        DeterministicState state2 = dfa.Start.Transaction['a'];
+        Assert.Equal(state2, state2.Transaction['a']);
+
+        DeterministicState state3 = dfa.Start.Transaction['b'];
+        Assert.Empty(state3.Transaction);
+
+        Assert.Equal(3, dfa.FinalStates.Count);
+    }
+
+    [Fact]
+    public void NondeterministicStateSetTest()
+    {
+        Dictionary<NondeterministicStateSet, char> map = [];
+
+        NondeterministicState key1 = new();
+        NondeterministicState key2 = new();
+
+        map.Add(new NondeterministicStateSet([key1, key2]), 'a');
+
+        Assert.Equal('a', map[new NondeterministicStateSet([key2, key1])]);
+    }
+}