epiphany/crates/epiphany-core/src/event.rs

623 lines
22 KiB
Rust

//! The event taxonomy and the event arena (Chapter 5 §"The Event Arena").
//!
//! Events are the rhythmic atoms of the score. All events of all kinds live in
//! a single flat [`EventArena`] owned by the score; voices, cross-cutting
//! structures, and analysis layers hold [`EventId`]s, not events (Chapter 5
//! §"Design Principles": "Arena storage"). Every event carries its own
//! identifier, its voice membership, and its position, stored on the event so
//! operations can resolve context without traversing parents.
//!
//! ## Storage backend (QUICKSTART decision 2)
//!
//! The arena is a [`slotmap::SlotMap`] of events plus a hash index from
//! [`EventId`] to the slot key. The slotmap gives generation-checked
//! stale-handle detection (matching the spec's identifier-stability
//! requirement) and the index gives the required `O(1)`-amortized lookup by
//! `EventId` (Chapter 5 §"The Event Arena"). Canonical iteration is by
//! ascending `EventId` (Appendix D §"Ordered Iteration").
//!
//! ## Forward-declared engraving types
//!
//! The decoration payloads on events (articulations, dynamics, ornaments, stem
//! configuration, staff positions) are *introduced informally here and fully
//! defined in Chapter 7* (the spec says so explicitly); they belong to Agent E
//! (`epiphany-layout-ir`). This module carries minimal placeholders for them so
//! the event records have their Chapter 5 shape without pre-empting Chapter 7.
use std::collections::HashMap;
use slotmap::{new_key_type, SlotMap};
use crate::ids::{EventId, GraphicObjectId, VoiceId};
use crate::pitch::IdentifiedPitch;
use crate::time::{DurationBounds, EventDuration, EventPosition, MusicalDuration};
// --- Forward-declared engraving placeholders (Chapter 7 / Agent E). ---------
/// A staff line/space position for unpitched events and explicitly-placed
/// rests (Chapter 5). Placeholder: the full vertical model is Chapter 7's.
#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, Default)]
pub struct StaffPosition(pub i16);
/// Reference to an unpitched instrument member (snare, kick, …) for sound
/// mapping (Chapter 5). Placeholder for the audio-engine mapping.
#[derive(Copy, Clone, PartialEq, Eq, Hash, Debug, Default)]
pub struct UnpitchedMemberId(pub u32);
/// An articulation attached to an event. Placeholder (Chapter 7).
#[derive(Clone, PartialEq, Eq, Hash, Debug, Default)]
pub struct ArticulationMark;
/// A single-event dynamic marking. Placeholder (Chapter 7).
#[derive(Clone, PartialEq, Eq, Hash, Debug, Default)]
pub struct DynamicMark;
/// An ornament attached to an event. Placeholder (Chapter 7).
#[derive(Clone, PartialEq, Eq, Hash, Debug, Default)]
pub struct OrnamentMark;
/// Stem configuration (direction, length adjustment, hidden). Placeholder
/// (Chapter 7).
#[derive(Clone, PartialEq, Eq, Hash, Debug, Default)]
pub struct StemConfiguration;
/// Hints constraining an indeterminate event. Placeholder for the full hint
/// model; carries the duration bounds and alternative-event references, which
/// are structural.
#[derive(Clone, PartialEq, Eq, Hash, Debug, Default)]
pub struct IndeterminacyHints {
pub duration_bounds: Option<DurationBounds>,
pub alternatives: Vec<EventId>,
pub textual_instruction: Option<String>,
}
/// Visual representation of a trajectory. Placeholder (Chapter 7).
#[derive(Clone, PartialEq, Eq, Hash, Debug, Default)]
pub struct TrajectoryDisplay;
/// A playback parameter binding for graphic content. Placeholder (audio
/// engine).
#[derive(Clone, PartialEq, Eq, Hash, Debug, Default)]
pub struct PlaybackBinding;
/// Rendering hints for a cue. Placeholder (Chapter 7).
#[derive(Clone, PartialEq, Eq, Hash, Debug, Default)]
pub struct CueRendering;
// --- The event taxonomy (Chapter 5 §"The Event Type"). ----------------------
/// Whether a note is a grace note, and of what kind (Chapter 5).
#[derive(Clone, PartialEq, Eq, Hash, Debug)]
pub enum GraceKind {
Acciaccatura,
Appoggiatura,
Unmeasured,
MeasuredFraction(MusicalDuration),
}
/// A pitched event: one or more identified pitches sounding together
/// (Chapter 5 §"Pitched Events"). A single pitch is a note; multiple pitches
/// are a chord.
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct PitchedEvent {
pub id: EventId,
pub voice: VoiceId,
pub position: EventPosition,
pub duration: EventDuration,
/// One or more identified pitches. Must be non-empty (use [`Rest`] for the
/// no-pitch case); enforced by [`PitchedEvent::is_well_formed`].
pub pitches: Vec<IdentifiedPitch>,
pub articulations: Vec<ArticulationMark>,
pub dynamic: Option<DynamicMark>,
pub ornaments: Vec<OrnamentMark>,
pub stem: StemConfiguration,
pub grace: Option<GraceKind>,
}
impl PitchedEvent {
/// A pitched event must have at least one pitch (Chapter 5: "Empty pitch
/// lists are forbidden").
pub fn is_well_formed(&self) -> bool {
!self.pitches.is_empty()
}
}
/// An unpitched percussion event (Chapter 5 §"Unpitched Events").
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct UnpitchedEvent {
pub id: EventId,
pub voice: VoiceId,
pub position: EventPosition,
pub duration: EventDuration,
pub staff_position: StaffPosition,
pub instrument_member: UnpitchedMemberId,
pub articulations: Vec<ArticulationMark>,
pub dynamic: Option<DynamicMark>,
pub stem: StemConfiguration,
pub grace: Option<GraceKind>,
}
/// A rest: a duration without a sounding event (Chapter 5 §"Rests").
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct Rest {
pub id: EventId,
pub voice: VoiceId,
pub position: EventPosition,
pub duration: EventDuration,
pub vertical_position: Option<StaffPosition>,
pub visible: bool,
}
/// What aspect of an indeterminate event is indeterminate (Chapter 5).
#[derive(Clone, PartialEq, Eq, Hash, Debug)]
pub enum IndeterminacyKind {
Pitch,
Duration,
Choice,
Compound(Vec<IndeterminacyKind>),
}
/// An event whose pitch, duration, or choice is deliberately indeterminate
/// (Chapter 5 §"Indeterminate Events").
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct IndeterminateEvent {
pub id: EventId,
pub voice: VoiceId,
pub position: EventPosition,
pub duration: EventDuration,
pub indeterminacy: IndeterminacyKind,
pub hints: IndeterminacyHints,
}
/// An endpoint of a trajectory: a reference to another event's pitch, or an
/// explicit pitch local to the trajectory (Chapter 5 §"Trajectory Events").
#[derive(Clone, PartialEq, Eq, Debug)]
pub enum TrajectoryEndpoint {
/// A pitch belonging to another event.
EventPitch(crate::ids::PitchId),
/// An explicit identified pitch local to this trajectory; participates in
/// spelling and identity like an embedded pitch.
ExplicitPitch(IdentifiedPitch),
}
/// The shape of a trajectory between its endpoints (Chapter 5).
#[derive(Clone, PartialEq, Eq, Debug)]
pub enum TrajectoryShape {
Linear,
Exponential,
/// Control points (placeholder geometry; full type in Chapter 7).
Curve,
/// A stepwise sequence of identified pitches.
Stepwise(Vec<IdentifiedPitch>),
}
/// A continuous pitch motion: glissando, portamento, or pitch bend
/// (Chapter 5 §"Trajectory Events").
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct TrajectoryEvent {
pub id: EventId,
pub voice: VoiceId,
pub position: EventPosition,
pub duration: EventDuration,
pub start: TrajectoryEndpoint,
pub end: TrajectoryEndpoint,
pub shape: TrajectoryShape,
pub display: TrajectoryDisplay,
}
/// An event whose primary content is graphic (Chapter 5 §"Graphic Events").
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct GraphicEvent {
pub id: EventId,
pub voice: VoiceId,
pub position: EventPosition,
pub duration: EventDuration,
pub graphics: Vec<GraphicObjectId>,
pub playback_bindings: Vec<PlaybackBinding>,
}
/// A small-print rendering of music from another voice/instrument
/// (Chapter 5 §"Cue Events").
#[derive(Clone, PartialEq, Eq, Debug)]
pub struct CueEvent {
pub id: EventId,
pub voice: VoiceId,
pub position: EventPosition,
pub duration: EventDuration,
pub source: Vec<EventId>,
pub rendering: CueRendering,
}
/// A rhythmic event of any kind (Chapter 5 §"The Event Type").
#[derive(Clone, PartialEq, Eq, Debug)]
pub enum Event {
Pitched(PitchedEvent),
Unpitched(UnpitchedEvent),
Rest(Rest),
Indeterminate(IndeterminateEvent),
Trajectory(TrajectoryEvent),
Graphic(GraphicEvent),
Cue(CueEvent),
}
impl Event {
/// The event's identifier.
pub fn id(&self) -> EventId {
match self {
Event::Pitched(e) => e.id,
Event::Unpitched(e) => e.id,
Event::Rest(e) => e.id,
Event::Indeterminate(e) => e.id,
Event::Trajectory(e) => e.id,
Event::Graphic(e) => e.id,
Event::Cue(e) => e.id,
}
}
/// The voice that owns this event.
pub fn voice(&self) -> VoiceId {
match self {
Event::Pitched(e) => e.voice,
Event::Unpitched(e) => e.voice,
Event::Rest(e) => e.voice,
Event::Indeterminate(e) => e.voice,
Event::Trajectory(e) => e.voice,
Event::Graphic(e) => e.voice,
Event::Cue(e) => e.voice,
}
}
/// The event's position within its voice and region.
pub fn position(&self) -> &EventPosition {
match self {
Event::Pitched(e) => &e.position,
Event::Unpitched(e) => &e.position,
Event::Rest(e) => &e.position,
Event::Indeterminate(e) => &e.position,
Event::Trajectory(e) => &e.position,
Event::Graphic(e) => &e.position,
Event::Cue(e) => &e.position,
}
}
/// The event's duration.
pub fn duration(&self) -> &EventDuration {
match self {
Event::Pitched(e) => &e.duration,
Event::Unpitched(e) => &e.duration,
Event::Rest(e) => &e.duration,
Event::Indeterminate(e) => &e.duration,
Event::Trajectory(e) => &e.duration,
Event::Graphic(e) => &e.duration,
Event::Cue(e) => &e.duration,
}
}
/// Sets the voice membership (used by generators and edit operations).
pub fn set_voice(&mut self, voice: VoiceId) {
match self {
Event::Pitched(e) => e.voice = voice,
Event::Unpitched(e) => e.voice = voice,
Event::Rest(e) => e.voice = voice,
Event::Indeterminate(e) => e.voice = voice,
Event::Trajectory(e) => e.voice = voice,
Event::Graphic(e) => e.voice = voice,
Event::Cue(e) => e.voice = voice,
}
}
/// Sets the event's region-local position (used by time-model migration
/// during canonical operation reduction).
pub fn set_position(&mut self, position: EventPosition) {
match self {
Event::Pitched(e) => e.position = position,
Event::Unpitched(e) => e.position = position,
Event::Rest(e) => e.position = position,
Event::Indeterminate(e) => e.position = position,
Event::Trajectory(e) => e.position = position,
Event::Graphic(e) => e.position = position,
Event::Cue(e) => e.position = position,
}
}
/// Appends references to every [`IdentifiedPitch`] this event embeds:
/// chord pitches for [`Event::Pitched`], and explicit/stepwise pitches for
/// [`Event::Trajectory`]. Used by the pitch-uniqueness invariant.
pub fn collect_identified_pitches<'a>(&'a self, out: &mut Vec<&'a IdentifiedPitch>) {
match self {
Event::Pitched(e) => out.extend(e.pitches.iter()),
Event::Trajectory(e) => {
for ep in [&e.start, &e.end] {
if let TrajectoryEndpoint::ExplicitPitch(ip) = ep {
out.push(ip);
}
}
if let TrajectoryShape::Stepwise(ps) = &e.shape {
out.extend(ps.iter());
}
}
_ => {}
}
}
}
new_key_type! {
/// A generation-checked handle into the [`EventArena`]'s slot storage.
/// Stale handles are detected by the slotmap rather than silently aliasing
/// a recycled slot (the identifier-stability discipline of Chapter 5).
pub struct EventKey;
}
/// Why an arena insertion failed.
#[derive(Copy, Clone, PartialEq, Eq, Debug)]
pub enum ArenaError {
/// An event with this identifier already exists. Identifiers are unique
/// within a score (Chapter 5 invariant 11) and never reused.
DuplicateId(EventId),
/// A [`PitchedEvent`] was inserted with no pitches. "A `PitchedEvent` MUST
/// have at least one pitch. Empty pitch lists are forbidden; use `Rest` for
/// the no-pitch case." (Chapter 5 §"Pitched Events".) Enforced at the
/// construction boundary so a malformed pitched event never enters the
/// arena in the first place.
EmptyPitchedEvent(EventId),
}
impl core::fmt::Display for ArenaError {
fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
match self {
ArenaError::DuplicateId(id) => write!(f, "duplicate EventId {id:?} in arena"),
ArenaError::EmptyPitchedEvent(id) => {
write!(f, "pitched event {id:?} has no pitches (Chapter 5)")
}
}
}
}
impl std::error::Error for ArenaError {}
/// The flat arena of all events in a score (Chapter 5 §"The Event Arena").
///
/// Observable contract: `O(1)`-amortized lookup by [`EventId`] and stable
/// handles for the lifetime of the event. Canonical iteration
/// ([`EventArena::iter_canonical`]) is by ascending `EventId`.
#[derive(Clone, Debug, Default)]
pub struct EventArena {
slots: SlotMap<EventKey, Event>,
by_id: HashMap<EventId, EventKey>,
}
impl PartialEq for EventArena {
fn eq(&self, other: &Self) -> bool {
let ids = self.ids_canonical();
ids == other.ids_canonical() && ids.into_iter().all(|id| self.get(id) == other.get(id))
}
}
impl Eq for EventArena {}
impl EventArena {
/// An empty arena.
pub fn new() -> Self {
EventArena {
slots: SlotMap::with_key(),
by_id: HashMap::new(),
}
}
/// Inserts an event, rejecting a duplicate identifier (invariant 11) and a
/// pitched event with no pitches (Chapter 5 §"Pitched Events"). Enforcing
/// the latter here keeps `PitchedEvent::is_well_formed` from being merely
/// advisory: an empty pitched event cannot enter the arena.
pub fn insert(&mut self, event: Event) -> Result<EventKey, ArenaError> {
let id = event.id();
if let Event::Pitched(p) = &event {
if !p.is_well_formed() {
return Err(ArenaError::EmptyPitchedEvent(id));
}
}
if self.by_id.contains_key(&id) {
return Err(ArenaError::DuplicateId(id));
}
let key = self.slots.insert(event);
self.by_id.insert(id, key);
Ok(key)
}
/// `O(1)`-amortized lookup by identifier.
pub fn get(&self, id: EventId) -> Option<&Event> {
self.by_id.get(&id).and_then(|k| self.slots.get(*k))
}
/// Mutable lookup by identifier.
pub fn get_mut(&mut self, id: EventId) -> Option<&mut Event> {
match self.by_id.get(&id) {
Some(k) => self.slots.get_mut(*k),
None => None,
}
}
/// Whether an event with this identifier is live in the arena.
pub fn contains(&self, id: EventId) -> bool {
self.by_id.contains_key(&id)
}
/// Removes an event by identifier (the live-storage side of a tombstone;
/// tombstone *tracking* is `epiphany-ops`, Chapter 6). The identifier is
/// never re-minted, so re-inserting the same id is a caller error.
pub fn remove(&mut self, id: EventId) -> Option<Event> {
let key = self.by_id.remove(&id)?;
self.slots.remove(key)
}
/// Identifiers whose index entry is inconsistent: the `by_id` key no longer
/// resolves, or resolves to an event whose own `id()` differs from the key.
/// This catches post-insertion corruption via [`EventArena::get_mut`] (e.g.
/// mutating an event's id), which the safe [`EventArena::insert`] path
/// cannot produce. Empty for a well-formed arena.
pub fn index_inconsistencies(&self) -> Vec<EventId> {
self.by_id
.iter()
.filter(|(id, key)| self.slots.get(**key).map(|e| e.id()) != Some(**id))
.map(|(id, _)| *id)
.collect()
}
/// Live pitched events that are malformed (no pitches). [`EventArena::insert`]
/// rejects these, but [`EventArena::get_mut`] could clear a chord's pitches
/// after insertion; this re-checks (Chapter 5 §"Pitched Events").
pub fn malformed_pitched_events(&self) -> Vec<EventId> {
self.slots
.values()
.filter_map(|e| match e {
Event::Pitched(p) if !p.is_well_formed() => Some(p.id),
_ => None,
})
.collect()
}
/// Number of live events.
pub fn len(&self) -> usize {
self.slots.len()
}
/// Whether the arena holds no live events.
pub fn is_empty(&self) -> bool {
self.slots.is_empty()
}
/// Iterates live events in unspecified (storage) order. Use
/// [`EventArena::iter_canonical`] where canonical output depends on order.
pub fn iter(&self) -> impl Iterator<Item = &Event> {
self.slots.values()
}
/// Live event identifiers, ascending (Appendix D §"Ordered Iteration":
/// lexicographic on the identifier's canonical byte form, which for these
/// identifiers is numeric order).
pub fn ids_canonical(&self) -> Vec<EventId> {
let mut ids: Vec<EventId> = self.by_id.keys().copied().collect();
ids.sort();
ids
}
/// Iterates live events in canonical [`EventId`] order.
pub fn iter_canonical(&self) -> impl Iterator<Item = &Event> + '_ {
self.ids_canonical()
.into_iter()
.map(move |id| self.get(id).expect("indexed id resolves"))
}
}
#[cfg(test)]
mod tests {
use super::*;
use crate::ids::ReplicaId;
use crate::pitch::{
AcousticPitch, AcousticRealization, CmnNominal, Pitch, PitchSpaceId, PitchSpacePosition,
ScalePosition, TuningReference,
};
use crate::time::{MusicalPosition, RationalTime};
fn rest(id: EventId, voice: VoiceId, beat: i64) -> Event {
Event::Rest(Rest {
id,
voice,
position: EventPosition::Musical(MusicalPosition(RationalTime::new(beat, 4).unwrap())),
duration: EventDuration::Musical(MusicalDuration(RationalTime::new(1, 4).unwrap())),
vertical_position: None,
visible: true,
})
}
#[test]
fn arena_lookup_and_duplicate_rejection() {
let mut arena = EventArena::new();
let r = ReplicaId(1);
let v = VoiceId::new(r, 100);
let e0 = EventId::new(r, 0);
let e1 = EventId::new(r, 1);
arena.insert(rest(e0, v, 0)).unwrap();
arena.insert(rest(e1, v, 1)).unwrap();
assert_eq!(arena.len(), 2);
assert!(arena.contains(e0));
assert_eq!(arena.get(e0).unwrap().id(), e0);
// Duplicate id rejected.
assert_eq!(
arena.insert(rest(e0, v, 2)),
Err(ArenaError::DuplicateId(e0))
);
}
#[test]
fn empty_pitched_event_is_rejected_at_insertion() {
let mut arena = EventArena::new();
let r = ReplicaId(1);
let v = VoiceId::new(r, 1);
let eid = EventId::new(r, 0);
let empty = Event::Pitched(PitchedEvent {
id: eid,
voice: v,
position: EventPosition::Musical(MusicalPosition::origin()),
duration: EventDuration::Musical(MusicalDuration::whole()),
pitches: vec![],
articulations: vec![],
dynamic: None,
ornaments: vec![],
stem: StemConfiguration,
grace: None,
});
assert_eq!(arena.insert(empty), Err(ArenaError::EmptyPitchedEvent(eid)));
assert!(arena.is_empty());
}
#[test]
fn canonical_iteration_is_by_ascending_id() {
let mut arena = EventArena::new();
let r = ReplicaId(1);
let v = VoiceId::new(r, 100);
// Insert out of id order.
for c in [5u64, 1, 9, 3] {
arena.insert(rest(EventId::new(r, c), v, c as i64)).unwrap();
}
let ids: Vec<u64> = arena.iter_canonical().map(|e| e.id().counter()).collect();
assert_eq!(ids, vec![1, 3, 5, 9]);
}
#[test]
fn collects_embedded_and_trajectory_pitches() {
let r = ReplicaId(1);
let v = VoiceId::new(r, 1);
let mk_ip = |c: u64| IdentifiedPitch {
id: crate::ids::PitchId::new(r, c),
pitch: Pitch {
scale_position: ScalePosition {
space: PitchSpaceId::new("cmn-12"),
position: PitchSpacePosition::Cmn {
nominal: CmnNominal::C,
alteration: 0,
octave: 4,
},
},
acoustic: AcousticPitch {
tuning: TuningReference::Inherit,
realization: AcousticRealization::Implicit,
},
},
};
let chord = Event::Pitched(PitchedEvent {
id: EventId::new(r, 0),
voice: v,
position: EventPosition::Musical(MusicalPosition::origin()),
duration: EventDuration::Musical(MusicalDuration::whole()),
pitches: vec![mk_ip(10), mk_ip(11)],
articulations: vec![],
dynamic: None,
ornaments: vec![],
stem: StemConfiguration,
grace: None,
});
let mut out = Vec::new();
chord.collect_identified_pitches(&mut out);
assert_eq!(out.len(), 2);
}
}