// Next implements plan.Plan Next interface.
func (r *ExplainDefaultPlan) Next(ctx context.Context) (row *plan.Row, err error) {
if r.lines == nil {
var buf bytes.Buffer
w := format.IndentFormatter(&buf, "│ ")
r.S.Explain(ctx, w)
r.lines = strings.Split(string(buf.Bytes()), "\n")
}
if r.cursor == len(r.lines)-1 {
return
}
row = &plan.Row{
Data: []interface{}{r.lines[r.cursor]},
}
r.cursor++
return
}
// Do returns explain result lines.
func (r *ExplainDefaultPlan) Do(ctx context.Context, f plan.RowIterFunc) error {
var buf bytes.Buffer
switch x := r.S.(type) {
default:
w := format.IndentFormatter(&buf, "│ ")
x.Explain(ctx, w)
}
a := bytes.Split(buf.Bytes(), []byte{'\n'})
for _, v := range a[:len(a)-1] {
if more, err := f(nil, []interface{}{string(v)}); !more || err != nil {
return err
}
}
return nil
}