Enum Change 

#[non_exhaustive]
pub enum Change {
    Context,
    Added,
    Removed,
}

What one line of a diff is: added, removed, or neither.

The other half of decision 19d7602d. A diff is a table of lines and the only thing the vocabulary was missing was a way for a line to say which side of the change it is on, so this rides on [Cells] rather than arriving as a Node::Diff carrying git’s data model.

Why three and not two

Context is a line that did not change, and it is most of a diff. Said as Option<Change> with None for context, a renderer could not tell an unchanged line from a line nobody marked, which is the same argument Syntax::Plain makes one type up.

#[non_exhaustive] for Syntax’s reason. A fourth kind – a moved line, a conflict side – is a plausible request and must not be a breaking release.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Context

The line is in both sides and did not change.

Added

The line is only in the new side.

Removed

The line is only in the old side.

Trait Implementations

impl Clone for Change

fn clone(&self) -> Change

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Change

impl Debug for Change

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Change

fn default() -> Change

Returns the “default value” for a type.

impl Eq for Change

impl Hash for Change

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Intent for Change

fn token(self) -> &'static str

The makeover intent token this resolves against.

impl PartialEq for Change

fn eq(&self, other: &Change) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Change