Add assignment 7

src/assignments/assignment07.rs

@@ -0,0 +1,29 @@
+//! Assignment 7: Mastering advanced types (2/2).
+//!
+//! The primary goal of this assignment is to understand generics, traits, and lifetimes.
+//!
+//! You should fill out the `todo!()` placeholders in such a way that `/scripts/grade-07.sh` works fine.
+//! See `assignment07_grade.rs` and `/scripts/grade-07.sh` for the test script.
+
+struct FindIter<'s, T: Eq> {
+    query: &'s [T],
+    base: &'s [T],
+    curr: usize,
+}
+
+impl<T: Eq> Iterator for FindIter<'_, T> {
+    type Item = usize;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        todo!()
+    }
+}
+
+/// Returns an iterator over substring query indexes in the base.
+pub fn find<'s, T: Eq>(query: &'s [T], base: &'s [T]) -> impl 's + Iterator<Item = usize> {
+    FindIter {
+        query,
+        base,
+        curr: 0,
+    }
+}