Merge pull request #43 from orxfun/fix/#42-backward-iter-from-back-node

bug with backward iterators created from the back node is fixed

Author: orxfun

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "orx-linked-list"
-version = "3.7.0"
+version = "3.8.0"
 edition = "2024"
 authors = ["orxfun <[email protected]>"]
 description = "A linked list implementation with unique features and an extended list of constant time methods providing high performance traversals and mutations."

src/lib.rs

@@ -29,10 +29,10 @@ pub mod pointers;
 mod type_aliases;
 mod variant;
 
+pub use list::List;
 pub use list::ends_traits::*;
 pub use list::iter_traits::*;
 pub use list::slice::{ListSlice, ListSliceMut};
-pub use list::List;
 pub use orx_selfref_col::{MemoryPolicy, NodeIdx, NodeIdxError};
 pub use type_aliases::{
     DoublyIdx, DoublyList, DoublyListLazy, DoublyListSlice, DoublyListSliceLazy,

src/list/iter_traits/doubly_iterable.rs

@@ -1,9 +1,9 @@
 use crate::{
+    Doubly, DoublyIdx,
     iter::{DoublyIter, DoublyIterPtr, DoublyLinkIter},
     list::helper_traits::HasDoublyEnds,
     pointers::DoublyPtr,
     type_aliases::{BACK_IDX, FRONT_IDX, OOB},
-    Doubly, DoublyIdx,
 };
 use core::iter::{Chain, Rev};
 use orx_pinned_vec::PinnedVec;
@@ -283,7 +283,7 @@ where
         M: 'a,
     {
         let b = self.col().try_get_ptr(idx).expect(OOB);
-        let a = self.ends().get(BACK_IDX).cloned();
+        let a = self.ends().get(FRONT_IDX).cloned();
         DoublyIter::new(self.col(), a, Some(b)).rev()
     }
 

tests/iter_from.rs

@@ -1,28 +1,20 @@
 use orx_linked_list::*;
 
-#[test]
-fn iter_from_singly() {
-    let mut list = SinglyList::new();
-    let mut idx42 = None;
-    for i in 0..324 {
-        let idx = list.push_front(i.to_string());
-        if i == 42 {
-            idx42 = Some(idx)
-        }
-    }
-
-    let idx42 = idx42.unwrap();
-
-    let vec: Vec<_> = list.iter().cloned().collect();
-    let index_of_42 = vec
+fn test_singly_iter_from(
+    list: &SinglyList<String>,
+    vec: &[String],
+    value: usize,
+    idx: NodeIdx<Singly<String>>,
+) {
+    let position = vec
         .iter()
         .enumerate()
-        .find(|(_, x)| x == &&42.to_string())
+        .find(|(_, x)| x == &&value.to_string())
         .unwrap()
         .0;
 
-    let vec_slice = &vec[index_of_42..];
-    let mut list_slice = list.iter_from(&idx42);
+    let vec_slice = &vec[position..];
+    let mut list_slice = list.iter_from(&idx);
     #[cfg(feature = "validation")]
     list.validate();
 
@@ -34,37 +26,51 @@ fn iter_from_singly() {
     assert!(list_slice.next().is_none());
 }
 
-#[test]
-fn iter_from_doubly() {
-    let mut list = DoublyList::new();
-    let mut idx42 = None;
-    for i in 0..324 {
-        let idx = match i % 3 == 0 {
-            true => list.push_back(i.to_string()),
-            false => list.push_front(i.to_string()),
-        };
+fn test_doubly_iter_from(
+    list: &DoublyList<String>,
+    vec: &[String],
+    value: usize,
+    idx: NodeIdx<Doubly<String>>,
+) {
+    let position = vec
+        .iter()
+        .enumerate()
+        .find(|(_, x)| x == &&value.to_string())
+        .unwrap()
+        .0;
 
-        if i == 42 {
-            idx42 = Some(idx)
-        }
+    let vec_slice = &vec[position..];
+    let mut list_slice = list.iter_from(&idx);
+    #[cfg(feature = "validation")]
+    list.validate();
+
+    for x in vec_slice {
+        let value = list_slice.next().unwrap();
+        assert_eq!(x, value);
     }
 
-    let idx42 = idx42.unwrap();
+    assert!(list_slice.next().is_none());
+}
 
-    let vec: Vec<_> = list.iter().cloned().collect();
-    let index_of_42 = vec
+fn test_doubly_iter_backward_from(
+    list: &DoublyList<String>,
+    vec: &[String],
+    value: usize,
+    idx: NodeIdx<Doubly<String>>,
+) {
+    let position = vec
         .iter()
         .enumerate()
-        .find(|(_, x)| x == &&42.to_string())
+        .find(|(_, x)| x == &&value.to_string())
         .unwrap()
         .0;
 
-    let vec_slice = &vec[index_of_42..];
-    let mut list_slice = list.iter_from(&idx42);
+    let vec_slice = &vec[0..=position];
+    let mut list_slice = list.iter_backward_from(&idx);
     #[cfg(feature = "validation")]
     list.validate();
 
-    for x in vec_slice {
+    for x in vec_slice.iter().rev() {
         let value = list_slice.next().unwrap();
         assert_eq!(x, value);
     }
@@ -73,39 +79,72 @@ fn iter_from_doubly() {
 }
 
 #[test]
-fn iter_backward_from_doubly() {
+fn iter_from_singly() {
+    let mut list = SinglyList::new();
+    let [mut idx_first, mut idx_last, mut idx42] = [None, None, None];
+    for i in 0..324 {
+        let idx = list.push_front(i.to_string());
+        match i {
+            0 => idx_first = Some(idx),
+            42 => idx42 = Some(idx),
+            323 => idx_last = Some(idx),
+            _ => {}
+        };
+    }
+
+    let vec: Vec<_> = list.iter().cloned().collect();
+
+    test_singly_iter_from(&list, &vec, 0, idx_first.unwrap());
+    test_singly_iter_from(&list, &vec, 323, idx_last.unwrap());
+    test_singly_iter_from(&list, &vec, 42, idx42.unwrap());
+}
+
+#[test]
+fn iter_from_doubly() {
     let mut list = DoublyList::new();
-    let mut idx42 = None;
+    let [mut idx_first, mut idx_last, mut idx42] = [None, None, None];
     for i in 0..324 {
         let idx = match i % 3 == 0 {
             true => list.push_back(i.to_string()),
             false => list.push_front(i.to_string()),
         };
 
-        if i == 42 {
-            idx42 = Some(idx)
-        }
+        match i {
+            0 => idx_first = Some(idx),
+            42 => idx42 = Some(idx),
+            323 => idx_last = Some(idx),
+            _ => {}
+        };
     }
 
-    let idx42 = idx42.unwrap();
-
     let vec: Vec<_> = list.iter().cloned().collect();
-    let index_of_42 = vec
-        .iter()
-        .enumerate()
-        .find(|(_, x)| x == &&42.to_string())
-        .unwrap()
-        .0;
 
-    let vec_slice = &vec[0..=index_of_42];
-    let mut list_slice = list.iter_backward_from(&idx42);
-    #[cfg(feature = "validation")]
-    list.validate();
+    test_doubly_iter_from(&list, &vec, 0, idx_first.unwrap());
+    test_doubly_iter_from(&list, &vec, 323, idx_last.unwrap());
+    test_doubly_iter_from(&list, &vec, 42, idx42.unwrap());
+}
 
-    for x in vec_slice.iter().rev() {
-        let value = list_slice.next().unwrap();
-        assert_eq!(x, value);
+#[test]
+fn iter_backward_from_doubly() {
+    let mut list = DoublyList::new();
+    let [mut idx_first, mut idx_last, mut idx42] = [None, None, None];
+    for i in 0..324 {
+        let idx = match i % 3 == 0 {
+            true => list.push_back(i.to_string()),
+            false => list.push_front(i.to_string()),
+        };
+
+        match i {
+            0 => idx_first = Some(idx),
+            42 => idx42 = Some(idx),
+            323 => idx_last = Some(idx),
+            _ => {}
+        };
     }
 
-    assert!(list_slice.next().is_none());
+    let vec: Vec<_> = list.iter().cloned().collect();
+
+    test_doubly_iter_backward_from(&list, &vec, 0, idx_first.unwrap());
+    test_doubly_iter_backward_from(&list, &vec, 323, idx_last.unwrap());
+    test_doubly_iter_backward_from(&list, &vec, 42, idx42.unwrap());
 }