let regularCases: [String: [(input: String, expected: Bool)]] = [
  // Basic cases
  "": [("", true), ("x", false), ("xy", false)],
  "x": [("", false), ("x", true), ("xy", false)],
  "x+": [("", false), ("x", true), ("xy", false), ("xx", true)],
  "x*": [("", true), ("x", true), ("xy", false), ("xx", true)],
  "x?": [("", true), ("x", true), ("xy", false), ("xx", false)],
  "x|y": [("", false), ("x", true), ("y", true), ("xx", false)],
  
  // Nested groups
  "(xy)+": [("", false), ("xy", true), ("xyxy", true), ("x", false)],
  "(x|y)*": [("", true), ("x", true), ("y", true), ("xy", true), ("yx", true), ("xyxy", true)],
  
  // Complex combinations
  "x(y|z)+": [("", false), ("x", false), ("xy", true), ("xz", true), ("xyz", true), ("xyzyz", true)],
  "(ab|cd)*": [("", true), ("ab", true), ("cd", true), ("abcd", true), ("cdab", true), ("abc", false)],
  
  // Multiple alternatives
  "a|b|c": [("", false), ("a", true), ("b", true), ("c", true), ("d", false), ("ab", false)],
  "(x|y)(a|b)": [("xa", true), ("xb", true), ("ya", true), ("yb", true), ("xx", false), ("ab", false)]
]


@Test func nfaToDfa() async throws {

  for (pattern, expectations) in regularCases {
    let n = TestNFA(pattern)
    let d = EquivalentDFA(n)
    for (input, expectedMatch) in expectations {
      #expect(n.recognizes(input) == expectedMatch, "pattern: \(pattern), input: \(input), nfa:\n\(n)")
      #expect(d.recognizes(input) == expectedMatch, "pattern: \(pattern), input: \(input), dfa:\n\(d)")
    }
  }
}