Add RocList from array

crates/roc_std/src/roc_list.rs

@@ -483,6 +483,12 @@ where
     }
 }
 
+impl<T, const SIZE: usize> From<[T; SIZE]> for RocList<T> {
+    fn from(array: [T; SIZE]) -> Self {
+        Self::from_iter(array)
+    }
+}
+
 impl<'a, T> IntoIterator for &'a RocList<T> {
     type Item = &'a T;
     type IntoIter = core::slice::Iter<'a, T>;

crates/roc_std/tests/test_roc_std.rs

@@ -221,6 +221,24 @@ mod test_roc_std {
         assert_eq!(from_iter, from_slice);
     }
 
+    #[test]
+    fn list_from_array() {
+        let elems: [i64; 5] = [1, 2, 3, 4, 5];
+        let from_slice = RocList::from_slice(&elems);
+        let from_array = RocList::from(elems);
+        assert_eq!(from_array, from_slice);
+        assert_eq!(from_array.capacity(), from_slice.capacity());
+    }
+
+    #[test]
+    fn list_from_array_zero_size() {
+        let elems: [(); 5] = [(), (), (), (), ()];
+        let from_slice = RocList::from_slice(&elems);
+        let from_array = RocList::from(elems);
+        assert_eq!(from_array, from_slice);
+        assert_eq!(from_array.capacity(), from_slice.capacity());
+    }
+
     #[test]
     fn roc_result_to_rust_result() {
         let greeting = "Hello, World!";