begin adding regex tests based on freeCodeCamp tutorial

test/regex-tests.sml

@@ -207,7 +207,7 @@ struct
 
   (* tests based on regex tutorial by FreeCodeCamp *)
   val freeCodeCampTests = describe "regex freeCodeCamp tests"
-    [test "The dog chased the cat" (fn _ =>
+    [ test "The dog chased the cat" (fn _ =>
         let
           (* arrange *)
           val sentence = "The dog chased the cat"
@@ -229,7 +229,53 @@ struct
             andalso caseInsensitiveMatches = expectedCaseInsensitive
         in
           Expect.isTrue (expected)
-       end)]
+        end)
+    , test "Somewhere Waldo is hiding in this text." (fn _ =>
+        let
+          (* arrange *)
+          val sentence = "Somewhere Waldo is hiding in this text."
+          val regexString = "Waldo"
+          val dfa = CsDfa.fromString regexString
+
+          (* act *)
+          val matches = CsDfa.matchString (dfa, sentence)
+
+          (* assert *)
+          val expectedMatches = [(10, 14)]
+        in
+          Expect.isTrue (expected = matches)
+        end)
+    , test "James has a pet cat." (fn _ =>
+        let
+          (* arrange *)
+          val sentence = "James has a pet cat."
+          val regexString = "dog|cat|bird|fish"
+          val dfa = CsDfa.fromString regexString
+
+          (* act *)
+          val matches = CsDfa.matchString (dfa, sentence)
+
+          (* assert *)
+          val expectedMatches = [(16, 18)]
+        in
+          Expect.isTrue (expected = matches)
+        end)
+    , test "Ignore Case While Matching" (fn _ =>
+        let
+          (* arrange *)
+          val sentence = "freeCodeCamp"
+          val regexString = "freecodecamp"
+          val dfa = CiDfa.fromString regexString
+
+          (* act *)
+          val matches = CiDfa.matchString (dfa, sentence)
+
+          (* assert *)
+          val expectedMatches = [(0, 11)]
+        in
+          Expect.isTrue (expected = matches)
+        end)
+    ]
 
   val tests =
     [ caseInsensitiveTests