Enum IndexLock 

pub enum IndexLock<'a> {
    Acquire,
    Held(&'a str),
}

What: How the rewrite of one index file is protected from a Git command that writes the same index. &'a str borrows the token of the migration whose lock is already held. Why: Git replaces an index through index.lock. A rewrite that runs by itself takes that lock, as Git does, before it reads the index and holds it until the new index is in place. The migration already holds the lock of every index while it completes the new checkout, so its rewrite uses the held lock instead of creating one.

In TS you’d write (pseudocode):

type IndexLock = { kind: 'acquire' } | { kind: 'held'; token: string };

Variants

Acquire

Create index.lock for the duration of the rewrite and remove it after.

Held(&'a str)

index.lock holds this token already; leave it in place for its owner to release.

Trait Implementations

impl<'a> Clone for IndexLock<'a>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a> Copy for IndexLock<'a>

impl<'a> Debug for IndexLock<'a>

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

Formats the value using the given formatter.

impl<'a> Eq for IndexLock<'a>

impl<'a> PartialEq for IndexLock<'a>

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

Equality operator ==.

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

Inequality operator !=.

impl<'a> StructuralPartialEq for IndexLock<'a>