BM25 equal to float32(0) when I using types.SearchReq.Logic for searching

[2guotou]

• GIT HASH: 6ed3775
• Go version: go1.13 linux/amd64

Description

1. Using types.FrequenciesIndex OR types.LocsIndex For Indexer
2. Using Custom Scorer
3. Not Using "Logic", doc.BM25 >= float32(0);
4. Using "Logic", The doc.BM25 == float32(0);