Struct DetachDetector 

pub struct DetachDetector { /* private fields */ }

Deterministic detach-chord detector.

feed and tick accept caller-supplied timestamps so unit tests can drive every state transition without sleeping. The detector is purely a state machine: it never spawns threads, never reads from a terminal, and never owns a clock of its own.

Contract

The detector’s behaviour is fully specified by the following rules:

1. Strict code+modifier equality. A key matches the chord’s prefix (or detach) slot only when both KeyCode and the full KeyModifiers bitfield are byte-for-byte equal to the configured event. Ctrl+B does not match Ctrl+Shift+B.
2. Prefix swallowing. While idle, observing the prefix transitions the detector to PrefixHeld and returns DetachOutcome::Armed; the prefix is consumed and is not forwarded to the pane until the timeout lapses or a mismatch is seen.
3. Chord completion. While PrefixHeld, observing the detach follow-up returns DetachOutcome::DetachRequested and the detector returns to idle without forwarding anything.
4. Mismatch forwarding. While PrefixHeld, observing any other event (including the prefix again) returns DetachOutcome::Forward(vec![prefix, event]) in that order, and the detector returns to idle.
5. Timeout flushing. A feed or tick call where now.saturating_duration_since(prefix_arrival) >= timeout flushes the held prefix as Forward(vec![prefix]) and returns the detector to idle. For feed, the new event is then processed against the now-idle detector and any extra forwarded events are appended after the flushed prefix.
6. Zero-timeout edge case. A Duration::ZERO timeout means any observation strictly after the prefix is treated as expired (>= is the comparison): the detector flushes the prefix and forwards the new event without ever firing the chord. Hosts that want chord behaviour must configure a non-zero timeout.
7. Equal prefix/detach edge case. If a chord is configured with prefix == detach, the detach branch is checked first while PrefixHeld, so pressing the shared key twice quickly enough returns DetachRequested.
8. Reusability. The detector is fully reusable after every terminal outcome: hosts may keep a single detector across sessions or runs. After DetachRequested, the detector is idle and a subsequent tick returns Forward(vec![]).

Implementations

impl DetachDetector

pub const DEFAULT_TIMEOUT: Duration

Default chord-completion window matching tmux’s interactive feel.

pub const fn new(chord: DetachChord) -> Self

Constructs a detector for the given chord with Self::DEFAULT_TIMEOUT.

pub const fn with_timeout(chord: DetachChord, timeout: Duration) -> Self

Constructs a detector with an explicit timeout window.

pub const fn chord(&self) -> &DetachChord

Returns the chord this detector matches.

pub const fn timeout(&self) -> Duration

Returns the configured chord-completion timeout.

pub const fn is_prefix_armed(&self) -> bool

Returns true while the detector has consumed the prefix and is waiting for the follow-up key.

pub fn reset(&mut self)

Resets the detector back to idle without forwarding anything.

pub fn feed(&mut self, event: KeyEvent, now: Instant) -> DetachOutcome

Feeds an event into the detector and returns the outcome.

now is the timestamp at which the event is observed. Tests pass a deterministic Instant so timeout edges can be exercised precisely. The detector never blocks and never reads Instant::now() internally.

pub fn tick(&mut self, now: Instant) -> DetachOutcome

Advances the detector’s clock without consuming an input event.

Hosts call this when they receive a non-key wakeup (poll loop tick, resize event, etc.) so the detector can release a held prefix once the timeout has lapsed. Returns Forward(vec![prefix]) when the timeout has elapsed; otherwise returns the current state.

Trait Implementations

impl Clone for DetachDetector

fn clone(&self) -> DetachDetector

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for DetachDetector

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

Formats the value using the given formatter.