Splitlab fix

week9/splitlab/src/split_pattern.rs

@@ -31,7 +31,7 @@ where
     /// Returns the next substring of the original `haystack` string, split by some delimiter
     /// pattern.
     ///
-    /// Panics if the delimiter is empty (length 0).
+    /// Should panic if the delimiter is empty (length 0).
     fn next(&mut self) -> Option<Self::Item> {
         todo!("Implement me!")
     }

week9/splitlab/src/split_str.rs

@@ -20,14 +20,10 @@ pub struct Split {
 impl Split {
     /// Creates a new `Split` instance with the given haystack and delimiter.
     ///
-    /// Panics if the delimiter is empty (length 0).
+    /// Should panic if the delimiter is empty (length 0).
     ///
     /// TODO(student): Replace the `'static` lifetimes with other lifetimes!
     pub fn new(haystack: &'static str, delimiter: &'static str) -> Self {
-        assert!(
-            !delimiter.is_empty(),
-            "Delimiter must not be an empty string"
-        );
 
         Self {
             remainder: Some(haystack),
@@ -46,9 +42,6 @@ impl Iterator for Split {
     type Item = &'static str;
 
     /// Returns the next substring of the original `haystack` string, split by some delimiter.
-    ///
-    /// If the delimiter is the empty string, returns the next character (as a string) to avoid
-    /// infinitely looping.
     fn next(&mut self) -> Option<Self::Item> {
         todo!("Implement me (make sure to fix the lifetimes!)")
     }

week9/splitlab/src/tests/pattern.rs

@@ -1,5 +1,11 @@
 use super::*;
 
+#[test]
+#[should_panic]
+fn test_pattern_empty_delimiter() {
+    let _ = SplitPattern::new(&String::from("a b c"), "").collect::<Vec<&str>>();
+}
+
 test_pattern!(
     test_crust_of_rust_until_char_test,
     "hello world",

week9/splitlab/src/tests/str.rs

@@ -15,6 +15,12 @@ fn test_str_compiles() {
     assert_eq!(results, vec!["a", "b", "c", "d", "e"]);
 }
 
+#[test]
+#[should_panic]
+fn test_str_empty_delimiter() {
+    let _ = Split::new(&String::from("a b c"), &String::from(""));
+}
+
 test_str!(
     test_crust_of_rust_it_works,
     "a b c d e",

week9/splitlab_ref/src/split_pattern.rs

@@ -31,7 +31,7 @@ where
     /// Returns the next substring of the original `haystack` string, split by some delimiter
     /// pattern.
     ///
-    /// Panics if the delimiter is empty (length 0).
+    /// Should panic if the delimiter is empty (length 0).
     fn next(&mut self) -> Option<Self::Item> {
         // If `remainder` is `None`, then there is nothing left to yield, and we should return
         // `None` immediately (with `?`).
@@ -42,7 +42,9 @@ where
             // If there is no delimiter in the remainder, return the entire remainder.
             return self.remainder.take();
         };
-        assert_ne!(start, end, "Delimiter cannot be empty");
+        if start == end {
+            panic!("Delimiter cannot be empty");
+        }
 
         // Compute the next string to yield as well as the new remainder.
         let next_str = &remainder[..start];

week9/splitlab_ref/src/split_str.rs

@@ -14,12 +14,11 @@ pub struct Split<'haystack, 'delimiter> {
 impl<'haystack, 'delimiter> Split<'haystack, 'delimiter> {
     /// Creates a new `Split` instance with the given haystack and delimiter.
     ///
-    /// Panics if the delimiter is empty (length 0).
+    /// Should panic if the delimiter is empty (length 0).
     pub fn new(haystack: &'haystack str, delimiter: &'delimiter str) -> Self {
-        assert!(
-            !delimiter.is_empty(),
-            "Delimiter must not be an empty string"
-        );
+        if delimiter.is_empty() {
+            panic!("Delimiter cannot be empty")
+        }
 
         Self {
             remainder: Some(haystack),
@@ -37,8 +36,6 @@ impl<'haystack> Iterator for Split<'haystack, '_> {
 
     /// Returns the next substring of the original `haystack` string, split by some delimiter.
     ///
-    /// If the delimiter is the empty string, returns the next character (as a string) to avoid
-    /// infinitely looping.
     fn next(&mut self) -> Option<Self::Item> {
         // If `remainder` is `None`, then there is nothing left to yield, and we should return
         // `None` immediately (with `?`).
@@ -51,7 +48,6 @@ impl<'haystack> Iterator for Split<'haystack, '_> {
         };
 
         let (start, end) = (index, index + self.delimiter.len());
-        assert_ne!(start, end, "Delimiter cannot be empty");
 
         // Compute the next string to yield as well as the new remainder.
         let next_str = &remainder[..start];

week9/splitlab_ref/src/tests/pattern.rs

@@ -1,5 +1,11 @@
 use super::*;
 
+#[test]
+#[should_panic]
+fn test_pattern_empty_delimiter() {
+    let _ = SplitPattern::new(&String::from("a b c"), "").collect::<Vec<&str>>();
+}
+
 test_pattern!(
     test_crust_of_rust_until_char_test,
     "hello world",

week9/splitlab_ref/src/tests/str.rs

@@ -15,6 +15,12 @@ fn test_str_compiles() {
     assert_eq!(results, vec!["a", "b", "c", "d", "e"]);
 }
 
+#[test]
+#[should_panic]
+fn test_str_empty_delimiter() {
+    let _ = Split::new(&String::from("a b c"), &String::from(""));
+}
+
 test_str!(
     test_crust_of_rust_it_works,
     "a b c d e",