Arpeggios seem to be working

Project.toml

@@ -4,7 +4,11 @@ authors = ["David Sanders <dpsanders@gmail.com> and contributors"]
 version = "1.0.0-DEV"
 
 [deps]
+ColorTypes = "3da002f7-5984-5a60-b8a6-cbb66c0b333f"
+Colors = "5ae59095-9a9b-59fe-a467-6f913c188581"
+GeometryTypes = "4d00f742-c7ba-57c2-abde-4428a4b178cb"
 Luxor = "ae8d54c2-7ccd-5906-9d76-62fc9837b5bc"
+Parameters = "d96e819e-fc66-5662-9728-84c9c7592b0a"
 
 [compat]
 julia = "1"

src/intervals.jl

@@ -9,7 +9,7 @@ struct Interval
     quality::IntervalQuality
 end
 
-interval(distance, quality) = Interval(distance - 1, quality)
+# interval(distance, quality) = Interval(distance - 1, quality)
 
 function interval_name(distance::Int)
     if distance == 0
@@ -43,7 +43,6 @@ interval_quality_semitones = Dict(
 semitone(interval::Interval) =
     interval_semitones[interval.distance] + interval_quality_semitones[interval.quality]
 
-Base.:(<=)(n1::Pitch, n2::Pitch) = semitone(n1) <= semitone(n2)
 
 
 
@@ -64,10 +63,6 @@ function interval(n1::Pitch, n2::Pitch)
     base_interval_semitone = interval_semitones[total_note_distance %7]
     alteration_distance = semitone_distance - base_interval_semitone
 
-
-
-    @show note_distance, total_note_distance, semitone_distance, base_interval_semitone, alteration_distance
-
     if abs(note_distance) + 1 ∈ (1, 4, 5)
         if alteration_distance == 0
             return Interval(total_note_distance, Perfect)
@@ -89,10 +84,10 @@ function interval(n1::Pitch, n2::Pitch)
     end
 end
 
+interval( (n1, n2) ) = interval(n1, n2)
 
 tone(interval::Interval) = interval.distance
 
-
 function add_interval(n::Note, interval::Interval)
     new_tone = (tone(n) + tone(interval)) % 7
 

src/notes.jl

@@ -100,4 +100,6 @@ Note(n::Note) = n
 
 const middle_C = C4
 
-semitone(middle_C) 
+
+Base.isless(n1::Pitch, n2::Pitch) = semitone(n1) < semitone(n2)
+

src/scales.jl

@@ -74,8 +74,96 @@ end
 # iterate(s)
 
 const M = MusicTheory
-s = Scale(M.C4, major_scale)
+# s = Scale(M.C4, major_scale)
 
 # notes = Base.Iterators.take(s, 8) |> collect
 
-iterate(s, C4)
+# iterate(s, C4)
+
+s = Scale(M.C♮4, melodic_minor_scale)
+
+# makes thirds from scale tones:
+notes = Base.Iterators.take(s, 10) |> collect
+
+thirds = zip(notes, notes[3:end]) |> collect
+
+thirds_intervals = interval.(thirds)
+note_intervals = interval.(zip(notes, notes[2:end]))
+
+all = []
+for i in 1:(length(thirds)-1)
+    push!(all, (note_intervals[i], thirds_intervals[i], thirds_intervals[i+1]))
+end
+
+all
+
+1 |> collect
+
+
+
+
+# repeating pattern: how many scale notes to increment for each subsequent note
+
+arpeggio = [2, 2, 3]
+# broken thirds = [2, -1]
+# broken octaves = [7, -6]
+# broken arpeggio = [4, -2, 5] 
+
+# stateful iterator:
+mutable struct Motif
+    scale::Scale
+    pattern::Vector{Int}
+    current::Pitch
+    i
+end
+
+Motif(scale, pattern) = Motif(scale, pattern, first(iterate(scale)), 1)
+
+function Base.iterate(m::Motif)
+    return_value = m.current
+    current, next = iterate(scale)
+
+    for i in 1:m.pattern[m.i] - 1
+        current, next = iterate(scale, next)
+    end
+
+    m.i += 1
+    if m.i > length(m.pattern)
+        m.i = 1
+    end
+
+    m.current = current
+    return return_value, next
+end
+
+function Base.iterate(m::Motif, next)
+
+    return_value = next
+
+    for i in 1:m.pattern[m.i]
+        current, next = iterate(scale, next)
+    end
+
+    m.i += 1
+    if m.i > length(m.pattern)
+        m.i = 1
+    end
+
+    m.current = current
+
+    return return_value, next
+end
+
+
+Base.IteratorSize(::Type{Motif}) = Base.IsInfinite()
+Base.IteratorEltype(::Type{Motif}) = Base.HasEltype()
+Base.eltype(::Type{Motif}) = Pitch
+
+
+scale = Scale(M.C4, major_scale)
+arpeggio = Motif(scale, [2, 2, 3])
+
+# arpeggio
+
+current, next = iterate(arpeggio)
+current, next = iterate(arpeggio, next)