func NewTermPrefixSearcher(index index.Index, prefix string, field string, boost float64, explain bool) (*TermPrefixSearcher, error) {
// find the terms with this prefix
fieldReader, err := index.FieldReader(field, []byte(prefix), []byte(prefix))
// enumerate all the terms in the range
qsearchers := make([]search.Searcher, 0, 25)
tfd, err := fieldReader.Next()
for err == nil && tfd != nil {
qsearcher, err := NewTermSearcher(index, string(tfd.Term), field, 1.0, explain)
if err != nil {
return nil, err
}
qsearchers = append(qsearchers, qsearcher)
tfd, err = fieldReader.Next()
}
// build disjunction searcher of these ranges
searcher, err := NewDisjunctionSearcher(index, qsearchers, 0, explain)
if err != nil {
return nil, err
}
return &TermPrefixSearcher{
index: index,
prefix: prefix,
field: field,
explain: explain,
searcher: searcher,
}, nil
}
