Creates an index builder.

e.g. builder = Tx::Builder.new

Adds one word to the index.

e.g. builder.add("hoge")

Adds multiple words to the index.

e.g. builder.add_all(["hoge", "foo", "bar"])

Builds an index of words added by add and add_all, and save it to a file named file_name. The index can be loaded with Tx::Index.new.

e.g. builder.build("test.index")

Returns error log of index building.

Returns operation log of index building.