fix handout for extra credit

Author: connortsui20

week9/splitlab/src/split_pattern.rs

@@ -1,47 +1,39 @@
 /// A struct that represents split operations on a string.
-///
-/// TODO(student): You will need to change the `SplitPattern` struct to use lifetime parameter(s).
-pub struct SplitPattern<P> {
+pub struct SplitPattern<'a, P> {
     /// The remainder of the string that has not yet been split.
     ///
     /// Before the iterator has yielded any substrings, this is the entire string.
     /// After each call to `next`, this is the part of the string that has not yet been split.
-    ///
-    /// TODO(student): Replace the `'static` lifetime with something else!
-    remainder: Option<&'static str>,
+    remainder: Option<&'a str>,
 
     /// The generic delimiter pattern used to split the haystack string.
     delimiter: P,
 }
 
-impl<P> SplitPattern<P> {
+impl<'a, P> SplitPattern<'a, P> {
     /// Creates a new `Split` instance with the given haystack and delimiter.
-    ///
-    /// TODO(student): Replace the `'static` lifetime with something else!
-    pub fn new(haystack: &'static str, delimiter: P) -> Self {
+    pub fn new(haystack: &'a str, delimiter: P) -> Self {
         Self {
             remainder: Some(haystack),
             delimiter,
         }
     }
 }
 
-impl<P> Iterator for SplitPattern<P>
+impl<'a, P> Iterator for SplitPattern<'a, P>
 where
     P: Pattern,
 {
     /// This iterator yields substrings of the original `haystack` string, split by some delimiter
     /// pattern.
-    ///
-    /// TODO(student): Replace the `'static` lifetime with something else!
-    type Item = &'static str;
+    type Item = &'a str;
 
     /// Returns the next substring of the original `haystack` string, split by some delimiter
     /// pattern.
     ///
     /// Panics if the delimiter is empty (length 0).
     fn next(&mut self) -> Option<Self::Item> {
-        todo!("Implement me (make sure to fix the lifetimes!)")
+        todo!("Implement me!")
     }
 }