Make the change type be generic over any T rather &T (#31)

This makes the interface of this crate more flexible as the utility
methods such as `iter_changes` now also work if a container does not
contain references.

CHANGELOG.md

@@ -2,6 +2,12 @@
 
 All notable changes to similar are documented here.
 
+## Unreleased
+
+* Change the `Change` type and associated methods to work on any `T: Clone` instead
+  of `&T`.  This makes the `iter_changes` method also work on slices of integers
+  or other values.
+
 ## 1.3.0
 
 * Performance improvements for the LCS algorithm.

examples/nonstring.rs

@@ -0,0 +1,13 @@
+use similar::{capture_diff_slices, Algorithm};
+
+fn main() {
+    let old = vec![1, 2, 3];
+    let new = vec![1, 2, 4];
+    let ops = capture_diff_slices(Algorithm::Myers, &old, &new);
+
+    for op in ops {
+        for change in op.iter_changes(&old, &new) {
+            println!("{:?}", change);
+        }
+    }
+}

src/common.rs

@@ -159,3 +159,27 @@ pub fn group_diff_ops(mut ops: Vec<DiffOp>, n: usize) -> Vec<Vec<DiffOp>> {
 
     rv
 }
+
+#[test]
+fn test_non_string_iter_change() {
+    use crate::ChangeTag;
+
+    let old = vec![1, 2, 3];
+    let new = vec![1, 2, 4];
+    let ops = capture_diff_slices(Algorithm::Myers, &old, &new);
+    let changes: Vec<_> = ops
+        .iter()
+        .flat_map(|x| x.iter_changes(&old, &new))
+        .map(|x| (x.tag(), x.value()))
+        .collect();
+
+    assert_eq!(
+        changes,
+        vec![
+            (ChangeTag::Equal, 1),
+            (ChangeTag::Equal, 2),
+            (ChangeTag::Delete, 3),
+            (ChangeTag::Insert, 4),
+        ]
+    );
+}

src/iter.rs

@@ -11,7 +11,7 @@ use std::ops::{Index, Range};
 use crate::{Change, ChangeTag, DiffOp, DiffTag};
 
 /// Iterator for [`DiffOp::iter_changes`].
-pub struct ChangesIter<'lookup, 'data, Old: ?Sized, New: ?Sized, T: ?Sized> {
+pub struct ChangesIter<'lookup, Old: ?Sized, New: ?Sized, T> {
     old: &'lookup Old,
     new: &'lookup New,
     old_range: Range<usize>,
@@ -21,15 +21,13 @@ pub struct ChangesIter<'lookup, 'data, Old: ?Sized, New: ?Sized, T: ?Sized> {
     old_i: usize,
     new_i: usize,
     tag: DiffTag,
-    _marker: PhantomData<&'data T>,
+    _marker: PhantomData<T>,
 }
 
-impl<'lookup, 'data, Old, New, T> ChangesIter<'lookup, 'data, Old, New, T>
+impl<'lookup, Old, New, T> ChangesIter<'lookup, Old, New, T>
 where
-    Old: Index<usize, Output = &'data T> + ?Sized,
+    Old: Index<usize, Output = T> + ?Sized,
-    New: Index<usize, Output = &'data T> + ?Sized,
+    New: Index<usize, Output = T> + ?Sized,
-    T: 'data + ?Sized,
-    'data: 'lookup,
 {
     pub(crate) fn new(old: &'lookup Old, new: &'lookup New, op: DiffOp) -> Self {
         let (tag, old_range, new_range) = op.as_tag_tuple();
@@ -52,20 +50,19 @@ where
     }
 }
 
-impl<'lookup, 'data, Old, New, T> Iterator for ChangesIter<'lookup, 'data, Old, New, T>
+impl<'lookup, Old, New, T> Iterator for ChangesIter<'lookup, Old, New, T>
 where
-    Old: Index<usize, Output = &'data T> + ?Sized,
+    Old: Index<usize, Output = T> + ?Sized,
-    New: Index<usize, Output = &'data T> + ?Sized,
+    New: Index<usize, Output = T> + ?Sized,
-    T: 'data + ?Sized,
+    T: Clone,
-    'data: 'lookup,
 {
-    type Item = Change<'data, T>;
+    type Item = Change<T>;
 
     fn next(&mut self) -> Option<Self::Item> {
         match self.tag {
             DiffTag::Equal => {
                 if self.old_i < self.old_range.end {
-                    let value = self.old[self.old_i];
+                    let value = self.old[self.old_i].clone();
                     self.old_i += 1;
                     self.old_index += 1;
                     self.new_index += 1;
@@ -81,7 +78,7 @@ where
             }
             DiffTag::Delete => {
                 if self.old_i < self.old_range.end {
-                    let value = self.old[self.old_i];
+                    let value = self.old[self.old_i].clone();
                     self.old_i += 1;
                     self.old_index += 1;
                     Some(Change {
@@ -96,7 +93,7 @@ where
             }
             DiffTag::Insert => {
                 if self.new_i < self.new_range.end {
-                    let value = self.new[self.new_i];
+                    let value = self.new[self.new_i].clone();
                     self.new_i += 1;
                     self.new_index += 1;
                     Some(Change {
@@ -111,7 +108,7 @@ where
             }
             DiffTag::Replace => {
                 if self.old_i < self.old_range.end {
-                    let value = self.old[self.old_i];
+                    let value = self.old[self.old_i].clone();
                     self.old_i += 1;
                     self.old_index += 1;
                     Some(Change {
@@ -121,7 +118,7 @@ where
                         value,
                     })
                 } else if self.new_i < self.new_range.end {
-                    let value = self.new[self.new_i];
+                    let value = self.new[self.new_i].clone();
                     self.new_i += 1;
                     self.new_index += 1;
                     Some(Change {
@@ -147,7 +144,7 @@ mod text {
         old: &'slf [&'data T],
         new: &'slf [&'data T],
         ops: &'slf [DiffOp],
-        current_iter: Option<ChangesIter<'slf, 'data, [&'data T], [&'data T], T>>,
+        current_iter: Option<ChangesIter<'slf, [&'data T], [&'data T], &'data T>>,
     }
 
     impl<'slf, 'data, T> AllChangesIter<'slf, 'data, T>
@@ -173,7 +170,7 @@ mod text {
         T: PartialEq + 'data + ?Sized,
         'data: 'slf,
     {
-        type Item = Change<'data, T>;
+        type Item = Change<&'data T>;
 
         fn next(&mut self) -> Option<Self::Item> {
             loop {

src/text/inline.rs

@@ -159,8 +159,8 @@ impl<'s, T: DiffableStr + ?Sized> InlineChange<'s, T> {
     }
 }
 
-impl<'s, T: DiffableStr + ?Sized> From<Change<'s, T>> for InlineChange<'s, T> {
+impl<'s, T: DiffableStr + ?Sized> From<Change<&'s T>> for InlineChange<'s, T> {
-    fn from(change: Change<'s, T>) -> InlineChange<'s, T> {
+    fn from(change: Change<&'s T>) -> InlineChange<'s, T> {
         InlineChange {
             tag: change.tag(),
             old_index: change.old_index(),

src/text/mod.rs

@@ -495,7 +495,7 @@ impl<'old, 'new, 'bufs, T: DiffableStr + ?Sized + 'old + 'new> TextDiff<'old, 'n
     pub fn iter_changes<'x, 'slf>(
         &'slf self,
         op: &DiffOp,
-    ) -> ChangesIter<'slf, 'x, [&'x T], [&'x T], T>
+    ) -> ChangesIter<'slf, [&'x T], [&'x T], &'x T>
     where
         'x: 'slf,
         'old: 'x,
@@ -728,7 +728,7 @@ fn test_get_close_matches() {
 fn test_lifetimes_on_iter() {
     use crate::Change;
 
-    fn diff_lines<'x, T>(old: &'x T, new: &'x T) -> Vec<Change<'x, T::Output>>
+    fn diff_lines<'x, T>(old: &'x T, new: &'x T) -> Vec<Change<&'x T::Output>>
     where
         T: DiffableStrRef + ?Sized,
     {

src/types.rs

@@ -59,15 +59,15 @@ impl fmt::Display for ChangeTag {
 /// This type has additional methods that are only available for types
 /// implementing [`DiffableStr`](crate::text::DiffableStr).
 #[derive(Debug, PartialEq, Eq, Hash, Clone, Copy, Ord, PartialOrd)]
-pub struct Change<'s, T: ?Sized> {
+pub struct Change<T> {
     pub(crate) tag: ChangeTag,
     pub(crate) old_index: Option<usize>,
     pub(crate) new_index: Option<usize>,
-    pub(crate) value: &'s T,
+    pub(crate) value: T,
 }
 
 /// These methods are available for all change types.
-impl<'s, T: ?Sized> Change<'s, T> {
+impl<T: Clone> Change<T> {
     /// Returns the change tag.
     pub fn tag(&self) -> ChangeTag {
         self.tag
@@ -89,8 +89,8 @@ impl<'s, T: ?Sized> Change<'s, T> {
     /// this value is more or less useful.  If you always want to have a utf-8
     /// string it's best to use the [`Change::as_str`] and
     /// [`Change::to_string_lossy`] methods.
-    pub fn value(&self) -> &'s T {
+    pub fn value(&self) -> T {
-        self.value
+        self.value.clone()
     }
 }
 
@@ -270,16 +270,14 @@ impl DiffOp {
     ///     (ChangeTag::Insert, "blah"),
     /// ]);
     /// ```
-    pub fn iter_changes<'x, 'lookup, Old, New, T>(
+    pub fn iter_changes<'lookup, Old, New, T>(
         &self,
         old: &'lookup Old,
         new: &'lookup New,
-    ) -> ChangesIter<'lookup, 'x, Old, New, T>
+    ) -> ChangesIter<'lookup, Old, New, T>
     where
-        Old: Index<usize, Output = &'x T> + ?Sized,
+        Old: Index<usize, Output = T> + ?Sized,
-        New: Index<usize, Output = &'x T> + ?Sized,
+        New: Index<usize, Output = T> + ?Sized,
-        T: 'x + ?Sized,
-        'x: 'lookup,
     {
         ChangesIter::new(old, new, *self)
     }
@@ -436,7 +434,7 @@ mod text_additions {
     /// The text interface can produce changes over [`DiffableStr`] implementing
     /// values.  As those are generic interfaces for different types of strings
     /// utility methods to make working with standard rust strings more enjoyable.
-    impl<'s, T: DiffableStr + ?Sized> Change<'s, T> {
+    impl<'s, T: DiffableStr + ?Sized> Change<&'s T> {
         /// Returns the value as string if it is utf-8.
         pub fn as_str(&self) -> Option<&'s str> {
             T::as_str(self.value)
@@ -457,7 +455,7 @@ mod text_additions {
         }
     }
 
-    impl<'s, T: DiffableStr + ?Sized> fmt::Display for Change<'s, T> {
+    impl<'s, T: DiffableStr + ?Sized> fmt::Display for Change<&'s T> {
         fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
             write!(
                 f,