hmt-0.14: Haskell Music Theory

Safe HaskellSafe-Inferred

Music.Theory.Duration

Description

Common music notation duration model.

Synopsis

Documentation

data Duration Source

Common music notation durational model

Constructors

Duration 

Fields

division :: Integer

division of whole note

dots :: Integer

number of dots

multiplier :: Rational

tuplet modifier

Instances

duration_meq :: Duration -> Duration -> BoolSource

Are multipliers equal?

duration_compare_meq :: Duration -> Duration -> Maybe OrderingSource

Compare durations with equal multipliers.

order_pair :: Ordering -> (t, t) -> (t, t)Source

sort_pair :: (t -> t -> Ordering) -> (t, t) -> (t, t)Source

Sort a pair of equal type values using given comparison function.

 sort_pair compare ('b','a') == ('a','b')

sort_pair_m :: (t -> t -> Maybe Ordering) -> (t, t) -> Maybe (t, t)Source

no_dots :: (Duration, Duration) -> BoolSource

True if neither duration is dotted.

sum_dur_undotted :: (Integer, Integer) -> Maybe DurationSource

Sum undotted divisions, input is required to be sorted.

sum_dur_dotted :: (Integer, Integer, Integer, Integer) -> Maybe DurationSource

Sum dotted divisions, input is required to be sorted.

 sum_dur_dotted (4,1,4,1) == Just (Duration 2 1 1)
 sum_dur_dotted (4,0,2,1) == Just (Duration 1 0 1)
 sum_dur_dotted (8,1,4,0) == Just (Duration 4 2 1)
 sum_dur_dotted (16,0,4,2) == Just (Duration 2 0 1)

sum_dur :: Duration -> Duration -> Maybe DurationSource

Sum durations. Not all durations can be summed, and the present algorithm is not exhaustive.

 import Music.Theory.Duration.Name
 sum_dur quarter_note eighth_note == Just dotted_quarter_note
 sum_dur dotted_quarter_note eighth_note == Just half_note
 sum_dur quarter_note dotted_eighth_note == Just double_dotted_quarter_note

sum_dur' :: Duration -> Duration -> DurationSource

Erroring variant of sum_dur.

whole_note_division_to_musicxml_type :: Integer -> StringSource

Give MusicXML type for division.

 map whole_note_division_to_musicxml_type [2,4] == ["half","quarter"]

duration_to_musicxml_type :: Duration -> StringSource

Variant of whole_note_division_to_musicxml_type extracting division from Duration.

 duration_to_musicxml_type quarter_note == "quarter"

duration_to_lilypond_type :: Duration -> StringSource

Give Lilypond notation for Duration. Note that the duration multiplier is not written.

 import Music.Theory.Duration.Name
 map duration_to_lilypond_type [half_note,dotted_quarter_note] == ["2","4."]

whole_note_division_to_beam_count :: Integer -> Maybe IntegerSource

Calculate number of beams at notated division.

 whole_note_division_to_beam_count 32 == Just 3

duration_beam_count :: Duration -> IntegerSource

Calculate number of beams at Duration.

 map duration_beam_count [half_note,sixteenth_note] == [0,2]