Enum Presence 

pub enum Presence {
    Present,
    Vanished,
}

Whether an Entity was found by the Refresh that just ran.

A Vanished row keeps ~: every Known cell goes stale, which is both what the fold already produces and true, since those values are old and nothing will fix them. The condition itself is carried by a Warning rather than a fifth gutter mark, because the gutter summarises provenance rather than presence, and because a mark on a row cannot tell a reader the row is there. While probing is still limited to branch and default_branch, a Vanished Entity’s other, never-yet-probed cells fold as Unknown instead and can outrank that stale mark, so the row may render ? rather than ~ until every phase is probing; that is a transient of incomplete probing, not a second answer. Dismissal needs no undo, since session state never persists and a Repo that returns is rediscovered. Still open: the progressive-fill timing a Vanished row’s redraw should honour.

Variants

Present

Vanished

Trait Implementations

impl Clone for Presence

fn clone(&self) -> Presence

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Presence

impl Debug for Presence

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

Formats the value using the given formatter.

impl Default for Presence

fn default() -> Presence

Returns the “default value” for a type.

impl Eq for Presence

impl PartialEq for Presence

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Presence