Struct ReadView 

pub struct ReadView {
    pub include_superseded: bool,
    pub include_inactive: bool,
    pub include_out_of_window: bool,
    pub valid_as_of: Option<i64>,
}

0.8.20 Slice 10b (R-20-RV / R-20-NV) — the read view: the single knob that decides which canonical_nodes rows a read verb may see.

Every field is a relaxation: ReadView::default() is the STRICT view and compiles to exactly the predicates the five read verbs carried before this slice (superseded_at IS NULL AND state = 'active'), so the default read path is behaviourally unchanged. Flags compose INDEPENDENTLY — each one drops exactly one conjunct and no other.

The view is applied UNIFORMLY by Engine::read_get, Engine::read_get_many, Engine::read_list, Engine::read_list_filter and Engine::graph_neighbors — and, inside graph_neighbors, at EVERY position of EVERY direction’s recursive CTE (anchor, recursive join, final projection), so a relaxation cannot silently apply on one traversal position and not another.

World-time only

valid_as_of selects along the world-time (validity) axis only. Transaction-time / history_as_of is explicitly OUT OF SCOPE — this type deliberately has no way to ask “what did the database believe at time T”.

Fields

include_superseded: bool

Relax superseded_at IS NULL — include superseded (historical) versions of a row, not just the current one. false (default) keeps the shipped current-version-only behaviour.

On the point-lookup verbs (Engine::read_get / Engine::read_get_many) a logical_id can now match several rows; the slot resolves DETERMINISTICALLY to the highest write_cursor (the most recent version). Use Engine::read_list to enumerate history.

include_inactive: bool

Relax state = 'active' — include rows in a non-active lifecycle state (pending / deleted / purged). false (default) keeps the shipped active-only behaviour.

include_out_of_window: bool

Relax the validity-window predicate ENTIRELY — return rows whatever their [valid_from, valid_until) window, ignoring valid_as_of. false (default) filters to rows valid at the selected instant.

Note this is a NO-OP on any row with an unbounded (NULL/NULL) window, which is every row that predates schema step 22.

valid_as_of: Option<i64>

The instant (INTEGER epoch SECONDS, UTC) at which validity is evaluated. None (default) resolves to now at query time.

This is the :now seam: whichever way it resolves, the instant is compiled as a BOUND PARAMETER, never a datetime('now') SQL literal — which is what makes node validity deterministically testable without clock games. (The shipped EDGE temporal filter still inlines datetime('now'); that path is untouched by this slice.)

Trait Implementations

impl Clone for ReadView

fn clone(&self) -> ReadView

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for ReadView

impl Debug for ReadView

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

Formats the value using the given formatter.

impl Default for ReadView

fn default() -> ReadView

Returns the “default value” for a type.

impl Eq for ReadView

impl PartialEq for ReadView

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for ReadView