// Write writes a single feature and return the number of bytes written and any error.
// gff.Features are written as a canonical GFF line, seq.Sequences are written as inline
// sequence in GFF format (note that only sequences of feat.Moltype DNA, RNA and Protein
// are supported). gff.Sequences are not handled as they have a zero length. All other
// feat.Feature are written as sequence region metadata lines.
func (w *Writer) Write(f feat.Feature) (n int, err error) {
if f.Start() >= f.End() {
return 0, ErrBadFeature
}
w.header = true
switch f := f.(type) {
case *Feature:
defer func() {
if err != nil {
return
}
_, err = w.w.Write([]byte{'\n'})
if err != nil {
return
}
n++
}()
n, err = fmt.Fprintf(w.w, "%s\t%s\t%s\t%d\t%d\t",
f.SeqName,
f.Source,
f.Feature,
feat.ZeroToOne(f.FeatStart),
f.FeatEnd,
)
if err != nil {
return n, err
}
var _n int
if f.FeatScore != nil && !math.IsNaN(*f.FeatScore) {
if w.Precision < 0 {
_n, err = fmt.Fprintf(w.w, "%v", *f.FeatScore)
} else {
_n, err = fmt.Fprintf(w.w, "%.*f", w.Precision, *f.FeatScore)
}
if err != nil {
return n, err
}
n += _n
} else {
_, err = w.w.Write([]byte{'.'})
if err != nil {
return n, err
}
n++
}
_n, err = fmt.Fprintf(w.w, "\t%s\t%s",
f.FeatStrand,
f.FeatFrame,
)
n += _n
if err != nil {
return n, err
}
if f.FeatAttributes != nil {
_n, err = fmt.Fprintf(w.w, "\t%v", f.FeatAttributes)
if err != nil {
return n, err
}
n += _n
} else if f.Comments != "" {
_, err = w.w.Write([]byte{'\t'})
if err != nil {
return
}
n++
}
if f.Comments != "" {
_n, err = fmt.Fprintf(w.w, "\t%s", f.Comments)
n += _n
}
return n, err
case seq.Sequence:
sw := fasta.NewWriter(w.w, w.Width)
moltype := f.Alphabet().Moltype()
if moltype < feat.DNA || moltype > feat.Protein {
return 0, ErrNotHandled
}
sw.IDPrefix = [...][]byte{
feat.DNA: []byte("##DNA "),
feat.RNA: []byte("##RNA "),
feat.Protein: []byte("##Protein "),
}[moltype]
sw.SeqPrefix = []byte("##")
n, err = sw.Write(f)
if err != nil {
return n, err
}
var _n int
_n, err = w.w.Write([...][]byte{
feat.DNA: []byte("##end-DNA\n"),
feat.RNA: []byte("##end-RNA\n"),
feat.Protein: []byte("##end-Protein\n"),
}[moltype])
return n + _n, err
case Sequence:
return 0, ErrNotHandled
case *Region:
return fmt.Fprintf(w.w, "##sequence-region %s %d %d\n", f.SeqName, feat.ZeroToOne(f.RegionStart), f.RegionEnd)
default:
return fmt.Fprintf(w.w, "##sequence-region %s %d %d\n", f.Name(), feat.ZeroToOne(f.Start()), f.End())
}
}
