code: func Create(file string) *IndexWriter {
  	return &IndexWriter{
  		trigram:   sparse.NewSet(1 << 24),
  		nameData:  bufCreate(""),
  		nameIndex: bufCreate(""),
  		postIndex: bufCreate(""),
  		main:      bufCreate(file),
  		post:      make([]postEntry, 0, npost),
  		inbuf:     make([]byte, 16384),
  	}
  }
docs: // Create returns a new IndexWriter that will write the index to file.