Separate incorrect segmentation out of TEST_CASES

src/test_cases.rs

@@ -5,6 +5,7 @@ pub fn run(segmenter: &Segmenter) {
     for test in TEST_CASES.iter().copied() {
         assert_segments(segmenter, test);
     }
+    assert_segments(segmenter, FAIL);
 }
 
 pub fn assert_segments(segmenter: &Segmenter, s: &[&str]) {
@@ -96,7 +97,10 @@ pub const TEST_CASES: &[&[&str]] = &[
         "nothing", "in", "it", "to", "sit", "down", "on", "or", "to", "eat", "it", "was", "a",
         "hobbit", "hole", "and", "that", "means", "comfort",
     ],
-    &[
+];
+
+/// Incorrectly segmented, since the test data doesn't contain "unregarded"
+const FAIL: &[&str] = &[
     "far",
     "out",
     "in",
@@ -122,5 +126,4 @@ pub const TEST_CASES: &[&[&str]] = &[
     "regarded",
     "yellow",
     "sun",
-    ],
 ];