fix: change Iterator::zip to take IntoIterator instead of Iterator

starkware-libs · Jan 14, 2025 · ee750a4 · ee750a4
1 parent 7364d2b
commit ee750a4
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Showing 2 changed files with 18 additions and 10 deletions.
diff --git a/corelib/src/iter/traits/iterator.cairo b/corelib/src/iter/traits/iterator.cairo
@@ -121,14 +121,25 @@ pub trait Iterator<T> {
     /// assert_eq!(iter.next(), Option::None);
     /// ```
     ///
+    /// Since the argument to `zip()` uses [`IntoIterator`], we can pass
+    /// anything that can be converted into an [`Iterator`], not just an
+    /// [`Iterator`] itself. For example:
+    ///
+    /// ```
+    /// let mut iter = array![1, 2, 3].into_iter().zip(array![4, 5, 6]);
+    ///
+    /// assert_eq!(iter.next(), Option::Some((1, 4)));
+    /// assert_eq!(iter.next(), Option::Some((2, 5)));
+    /// assert_eq!(iter.next(), Option::Some((3, 6)));
+    /// assert_eq!(iter.next(), Option::None);
+    /// ``
+    ///
     /// [`enumerate`]: Iterator::enumerate
     /// [`next`]: Iterator::next
     #[inline]
-    fn zip<U, +Iterator<U> //, +IntoIterator<U>
-    >(
+    fn zip<U, impl UIntoIter: IntoIterator<U>, +Destruct<T>>(
         self: T, other: U,
-    ) -> Zip<T, U> {
-        zipped_iterator(self, other //.into_iter()
-        )
+    ) -> Zip<T, UIntoIter::IntoIter> {
+        zipped_iterator(self, other.into_iter())
     }
 }
diff --git a/corelib/src/test/iter_test.cairo b/corelib/src/test/iter_test.cairo
@@ -10,18 +10,15 @@ fn test_iter_adapter_map() {
 
 #[test]
 fn test_iterator_zip() {
-    let mut iter = array![1, 2, 3].into_iter().zip(array![4, 5, 6].into_iter());
+    let mut iter = array![1, 2, 3].into_iter().zip(array![4, 5, 6]);
 
     assert_eq!(iter.next(), Option::Some((1, 4)));
     assert_eq!(iter.next(), Option::Some((2, 5)));
     assert_eq!(iter.next(), Option::Some((3, 6)));
     assert_eq!(iter.next(), Option::None);
 
     // Nested zips
-    let mut iter = array![1, 2, 3]
-        .into_iter()
-        .zip(array![4, 5, 6].into_iter())
-        .zip(array![7, 8, 9].into_iter());
+    let mut iter = array![1, 2, 3].into_iter().zip(array![4, 5, 6]).zip(array![7, 8, 9]);
 
     assert_eq!(iter.next(), Option::Some(((1, 4), 7)));
     assert_eq!(iter.next(), Option::Some(((2, 5), 8)));