refactor: implement Order and Pattern types: slices returning default values for out of bound indices

track.go

@@ -2,17 +2,17 @@ package sointu
 
 type Track struct {
 	NumVoices int
-	Effect    bool     `yaml:",omitempty"`
-	Order     []int    `yaml:",flow"`
-	Patterns  [][]byte `yaml:",flow"`
+	Effect    bool      `yaml:",omitempty"`
+	Order     Order     `yaml:",flow"`
+	Patterns  []Pattern `yaml:",flow"`
 }
 
 func (t *Track) Copy() Track {
 	order := make([]int, len(t.Order))
 	copy(order, t.Order)
-	patterns := make([][]byte, len(t.Patterns))
+	patterns := make([]Pattern, len(t.Patterns))
 	for i, oldPat := range t.Patterns {
-		newPat := make([]byte, len(oldPat))
+		newPat := make(Pattern, len(oldPat))
 		copy(newPat, oldPat)
 		patterns[i] = newPat
 	}