melrōse musical expression player

package op import ( "bytes" "fmt" "github.com/emicklei/melrose/core" ) type Fraction struct { Target []core.Sequenceable Parameter core.HasValue } func NewFraction(parameter core.HasValue, target []core.Sequenceable) Fraction { return Fraction{ Target: target, Parameter: parameter, } } // Return a new Fraction in which any occurrences of "from" are replaced by "to". func (d Fraction) Replaced(from, to core.Sequenceable) core.Sequenceable { if core.IsIdenticalTo(d, from) { return to } return Fraction{Target: replacedAll(d.Target, from, to), Parameter: d.Parameter} } func (d Fraction) floatParameter() float32 { f := core.Float(d.Parameter) if f > 1.0 { f = 1.0 / f } return f } func (d Fraction) S() core.Sequence { f := d.floatParameter() target := [][]core.Note{} source := Join{Target: d.Target}.S().Notes for _, eachGroup := range source { mappedGroup := []core.Note{} for _, eachNote := range eachGroup { mappedGroup = append(mappedGroup, eachNote.WithFraction(f, eachNote.Dotted)) } target = append(target, mappedGroup) } return core.Sequence{Notes: target} } func (d Fraction) Storex() string { var b bytes.Buffer fmt.Fprintf(&b, "fraction(%s", core.Storex(d.Parameter)) core.AppendStorexList(&b, false, d.Target) fmt.Fprintf(&b, ")") return b.String() } func (d Fraction) ToNote() (core.Note, error) { if len(d.Target) == 0 { return core.Rest4, fmt.Errorf("cannot take note from [%s]", d.Storex()) } one, ok := d.Target[0].(core.NoteConvertable) if !ok { return core.Rest4, fmt.Errorf("cannot take note from [%v]", one) } not, err := one.ToNote() if err != nil { return not, err } return not.WithFraction(d.floatParameter(), not.Dotted), nil }