Fix Scale iterator

JuliaMusic · Dec 26, 2023 · acf3a22 · acf3a22
1 parent 641b2fe
commit acf3a22
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Showing 4 changed files with 17 additions and 19 deletions.
diff --git a/src/MusicTheory.jl b/src/MusicTheory.jl
@@ -1,7 +1,6 @@
 module MusicTheory
 
 export Pitch, Note, Accidental, NoteClass,
-    MajorScale, MinorScale,
     𝄫, ♭, ♮, ♯, 𝄪, C, D, E, F, G, A, B, C♮, D♮, E♮, F♮, G♮, A♮, B♮, C♯, D♯, E♯, F♯, G♯, A♯,
     B♯, C♭, D♭, E♭, F♭, G♭, A♭, B♭, C𝄫, D𝄫, E𝄫, F𝄫, G𝄫, A𝄫, B𝄫, C𝄪, D𝄪, E𝄪, F𝄪, G,
     note_names
@@ -12,8 +11,11 @@ export Interval, IntervalType, Major, Minor, Perfect, Augmented, Diminished,
 export Major_2nd, Minor_2nd, Major_3rd, Minor_3rd, Perfect_4th, Perfect_5th,
     Major_6th, Minor_6th, Major_7th, Minor_7th, Octave
 
+export Scale
 export major_scale, natural_minor_scale, melodic_minor_scale, harmonic_minor_scale
 
+
+
 include("notes.jl")
 include("intervals.jl")
 include("scales.jl")

diff --git a/src/intervals.jl b/src/intervals.jl
@@ -92,8 +92,6 @@ end
 
 tone(interval::Interval) = interval.distance
 
-semitone(interval::Interval) = 
-    interval_semitones[interval.distance] + interval_quality_semitones[interval.quality]
 
 function add_interval(n::Note, interval::Interval)
     new_tone = (tone(n) + tone(interval)) % 7

diff --git a/src/notes.jl b/src/notes.jl
@@ -76,16 +76,12 @@ semitone(note::NoteClass) = note_semitones[note]
 
 semitone(note::Note) = semitone(note.noteclass) + semitone(note.accidental)
 
+"Treats C0 as semitone 0"
 semitone(pitch::Pitch) = semitone(pitch.note) + 12 * pitch.octave
 
 NoteClass(pitch::Pitch) = pitch.note.noteclass
 Note(pitch::Pitch) = pitch.note
 
-"Treats C0 as semitone 0"
-function semitone(pitch::Pitch)
-    return semitone(pitch.note) + 12*pitch.octave
-end
-
 
 function find_accidental(which_semitone, noteclass)
     basic_semitone = semitone(noteclass)

diff --git a/src/scales.jl b/src/scales.jl
@@ -1,5 +1,3 @@
-
-
 struct Scale{T<:Union{Note, Pitch}}
     tonic::T
     steps::Dict{Note, Interval}
@@ -17,23 +15,20 @@ struct Scale{T<:Union{Note, Pitch}}
     end
 end
 
-# Scale2(M.C4, major_scale)
-
-Base.iterate(s::Scale{T}) where {T} = s.tonic
 
-function Base.iterate(s::Scale{T}, p::T) where {T}
+function Base.iterate(s::Scale{T}, p::T = s.tonic) where {T <: Union{Note, Pitch}}
     n = Note(p)
 
     !haskey(s.steps, n) && error("Note $n not in scale")
 
-    step = s.steps[n]
-    new_pitch = p + step
+    step = s.steps[n]  # an interval
+    new_p = p + step  # a note or a pitch, according to the type of p
 
-    return p, new_pitch
+    return (p, new_p)
 end
 
 Base.IteratorSize(::Type{Scale{T}}) where {T} = Base.IsInfinite()
-Base.IteratorEltype(::Type{Scale{T}}) where {T} = Base.HasEltype() 
+Base.IteratorEltype(::Type{Scale{T}}) where {T} = Base.HasEltype()
 Base.eltype(::Type{Scale{T}}) where {T} = T
 
 
@@ -76,4 +71,11 @@ end
 
 
 
-# iterate(s)
+# iterate(s)
+
+const M = MusicTheory
+s = Scale(M.C4, major_scale)
+
+# notes = Base.Iterators.take(s, 8) |> collect
+
+iterate(s, C4)