[Bug]: Retrieval exception after parsing of underlined term in file content.

[yz00000000]

Is there an existing issue for the same bug?

• I have checked the existing issues.

RAGFlow workspace code commit ID

1160b58

RAGFlow image version

0.15.1

Other environment information

No response

Actual behavior

General、table解析均存在无法搜索 有 ‘_’ 下划线的词语。

Expected behavior

No response

Steps to reproduce

使用https://github.com/infiniflow/ragflow/tree/v0.15.1/docker 中 docker-compose.yml安装ragflow，
按照后，导入存在 ‘_’ 的内容，
General、table解析均存在无法搜索 有 ‘_’ 下划线的词语。

Additional information

No response

[KevinHuSh]

It's designed as keyword search.
Both substring lookup or regex match are not supported yet.
So, abc will retrive nothing either.