rust_music/
chord.rs

1use crate::errors::ChordError;
2use crate::num::u7;
3use crate::Note;
4use crate::Result;
5
6/// Describes a set of notes played simultaneously
7#[derive(Debug, Default, Clone, PartialEq)]
8pub struct Chord {
9    /// `rhythm` is the length in beats that the `Chord` will take
10    /// in a `Phrase`.
11    ///
12    /// It cannot be longer than the longest `Note` of the `Chord`,
13    /// but it can be longer than some of the notes.
14    ///
15    /// It can be shorter than some (or all) of the notes.
16    /// This allows to play notes in the `Phrase` that start
17    /// while the previous `Chord` is still playing.
18    /// This also works with a `Chord` of one `Note`, to enable
19    /// these trailing notes with unique notes as well.
20    rhythm: f64,
21
22    /// The notes of the `Chord`. They can have different rhythm values.
23    /// This allows to stop some of the notes of the Chord before some others.
24    notes: Vec<Note>,
25}
26
27impl Chord {
28    /// Returns a new Chord based on the given rhythm value and notes
29    ///
30    /// # Arguments
31    ///
32    /// * `rhythm`: duration in beats that the `Chord` will take in a phrase.
33    ///   Some notes of the chord can last longer, but the next entry added to the
34    ///   phrase will start after the end of this `rhythm` value.
35    /// * `notes`: list of notes in the `Chord` (len must be 1 or more)
36    ///
37    /// # Errors
38    ///
39    /// * `ChordError::EmptyChord` if notes vec is empty
40    /// * `ChordError::RhythmTooLong` if `rhythm` is longer than the longest note
41    pub fn new(rhythm: f64, notes: Vec<Note>) -> Result<Self> {
42        if notes.is_empty() {
43            return Err(ChordError::EmptyChord.into());
44        }
45        let maxr = notes
46            .iter()
47            .map(Note::rhythm)
48            // .filter_map(|v| if v.is_nan() { None } else { Some(v) })
49            .fold(f64::NEG_INFINITY, f64::max);
50        if maxr < rhythm {
51            return Err(ChordError::RhythmTooLong.into());
52        }
53        Ok(Chord { rhythm, notes })
54    }
55
56    /// Returns a new Chord based on the given rhythm value, note pitches, and dynamic.
57    ///
58    /// # Arguments
59    ///
60    /// * `rhythm`:  duration in beats of the `Chord` and all the notes it contains
61    /// * `pitches`: list of the pitches of the notes of the `Chord`
62    /// * `dynamic`: dynamic that each note in the `Chord` will take
63    pub fn from_pitches(rhythm: f64, dynamic: u7, pitches: &[u7]) -> Result<Self> {
64        let notes: Result<Vec<_>> =
65            Note::new_sequence(rhythm, dynamic, pitches.iter().copied()).collect();
66        Self::new(rhythm, notes?)
67    }
68
69    /// Returns the rhythm value of the `Chord`
70    pub fn rhythm(&self) -> f64 {
71        self.rhythm
72    }
73
74    /// Returns the notes of the `Chord`
75    pub fn notes(&self) -> &[Note] {
76        self.notes.as_slice()
77    }
78}
rust_music/chord.rs

rust_music/
chord.rs
