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-rw-r--r--vendor/similar/src/algorithms/hook.rs178
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+/// A trait for reacting to an edit script from the "old" version to
+/// the "new" version.
+pub trait DiffHook: Sized {
+ /// The error produced from the hook methods.
+ type Error;
+
+ /// Called when lines with indices `old_index` (in the old version) and
+ /// `new_index` (in the new version) start an section equal in both
+ /// versions, of length `len`.
+ fn equal(&mut self, old_index: usize, new_index: usize, len: usize) -> Result<(), Self::Error> {
+ let _ = old_index;
+ let _ = new_index;
+ let _ = len;
+ Ok(())
+ }
+
+ /// Called when a section of length `old_len`, starting at `old_index`,
+ /// needs to be deleted from the old version.
+ fn delete(
+ &mut self,
+ old_index: usize,
+ old_len: usize,
+ new_index: usize,
+ ) -> Result<(), Self::Error> {
+ let _ = old_index;
+ let _ = old_len;
+ let _ = new_index;
+ Ok(())
+ }
+
+ /// Called when a section of the new version, of length `new_len`
+ /// and starting at `new_index`, needs to be inserted at position `old_index'.
+ fn insert(
+ &mut self,
+ old_index: usize,
+ new_index: usize,
+ new_len: usize,
+ ) -> Result<(), Self::Error> {
+ let _ = old_index;
+ let _ = new_index;
+ let _ = new_len;
+ Ok(())
+ }
+
+ /// Called when a section of the old version, starting at index
+ /// `old_index` and of length `old_len`, needs to be replaced with a
+ /// section of length `new_len`, starting at `new_index`, of the new
+ /// version.
+ ///
+ /// The default implementations invokes `delete` and `insert`.
+ ///
+ /// You can use the [`Replace`](crate::algorithms::Replace) hook to
+ /// automatically generate these.
+ #[inline(always)]
+ fn replace(
+ &mut self,
+ old_index: usize,
+ old_len: usize,
+ new_index: usize,
+ new_len: usize,
+ ) -> Result<(), Self::Error> {
+ self.delete(old_index, old_len, new_index)?;
+ self.insert(old_index, new_index, new_len)
+ }
+
+ /// Always called at the end of the algorithm.
+ #[inline(always)]
+ fn finish(&mut self) -> Result<(), Self::Error> {
+ Ok(())
+ }
+}
+
+impl<'a, D: DiffHook + 'a> DiffHook for &'a mut D {
+ type Error = D::Error;
+
+ #[inline(always)]
+ fn equal(&mut self, old_index: usize, new_index: usize, len: usize) -> Result<(), Self::Error> {
+ (*self).equal(old_index, new_index, len)
+ }
+
+ #[inline(always)]
+ fn delete(
+ &mut self,
+ old_index: usize,
+ old_len: usize,
+ new_index: usize,
+ ) -> Result<(), Self::Error> {
+ (*self).delete(old_index, old_len, new_index)
+ }
+
+ #[inline(always)]
+ fn insert(
+ &mut self,
+ old_index: usize,
+ new_index: usize,
+ new_len: usize,
+ ) -> Result<(), Self::Error> {
+ (*self).insert(old_index, new_index, new_len)
+ }
+
+ #[inline(always)]
+ fn replace(
+ &mut self,
+ old: usize,
+ old_len: usize,
+ new: usize,
+ new_len: usize,
+ ) -> Result<(), Self::Error> {
+ (*self).replace(old, old_len, new, new_len)
+ }
+
+ #[inline(always)]
+ fn finish(&mut self) -> Result<(), Self::Error> {
+ (*self).finish()
+ }
+}
+
+/// Wrapper [`DiffHook`] that prevents calls to [`DiffHook::finish`].
+///
+/// This hook is useful in situations where diff hooks are composed but you
+/// want to prevent that the finish hook method is called.
+pub struct NoFinishHook<D: DiffHook>(D);
+
+impl<D: DiffHook> NoFinishHook<D> {
+ /// Wraps another hook.
+ pub fn new(d: D) -> NoFinishHook<D> {
+ NoFinishHook(d)
+ }
+
+ /// Extracts the inner hook.
+ pub fn into_inner(self) -> D {
+ self.0
+ }
+}
+
+impl<D: DiffHook> DiffHook for NoFinishHook<D> {
+ type Error = D::Error;
+
+ #[inline(always)]
+ fn equal(&mut self, old_index: usize, new_index: usize, len: usize) -> Result<(), Self::Error> {
+ self.0.equal(old_index, new_index, len)
+ }
+
+ #[inline(always)]
+ fn delete(
+ &mut self,
+ old_index: usize,
+ old_len: usize,
+ new_index: usize,
+ ) -> Result<(), Self::Error> {
+ self.0.delete(old_index, old_len, new_index)
+ }
+
+ #[inline(always)]
+ fn insert(
+ &mut self,
+ old_index: usize,
+ new_index: usize,
+ new_len: usize,
+ ) -> Result<(), Self::Error> {
+ self.0.insert(old_index, new_index, new_len)
+ }
+
+ #[inline(always)]
+ fn replace(
+ &mut self,
+ old_index: usize,
+ old_len: usize,
+ new_index: usize,
+ new_len: usize,
+ ) -> Result<(), Self::Error> {
+ self.0.replace(old_index, old_len, new_index, new_len)
+ }
+
+ fn finish(&mut self) -> Result<(), Self::Error> {
+ Ok(())
+ }
+}