Inconsistency in loading topics

[jayparks]

Currently, there is mismatch in topics loading across search/dsearch/hsearch.

In pyserini/search/__main__.py

topics = get_topics(args.topics)

In pyserini/dsearch/__main__.py and pyserini/hsearch/__main__.py

if os.path.exists(args.topics) and args.topics.endswith('.json'):
        topics = json.load(open(args.topics))
    else:
        topics = get_topics(args.topics)

It would be good to allow loading json topics for search to ensure consistency.

[MXueguang]

Hi @jayparks,
Yes, we have a pending PR which will add this feature back. #405
We will merge it once we finish regression tests.

[MXueguang]

Hi @jayparks.
#405 is merged.
It supports loading from json.