"\." -> "invalid char escape"

[Dieterbe]

Describe the bug

A clause like |~ "[0-9]*s\" orgID" works fine. note how I'm escaping like \" to match ". This is as expected
However when I update the clause to this:

|~ "\.[0-9]*s\" orgID"

E.g. I merely add \. to match a literal .
It no longer works. I get the error parse error at line 1, col 98: invalid char escape
this is in Grafana v7.1.0-b8976df5pre (55ac97dccc) Explore mode, querying Loki-ops

[rbudiharso]

A pattern like {container_name="app"} |~ "\s4[00-99]{2}\s" also results in the same error. In this case I want to match HTTP status code like 400 or 401 (its 3 digit with single space around it).

[cyriltovena]

{job="default/prometheus"} |~ "\\s4[00-99]{2}\\s" This works.

@Dieterbe |~ "\\.[0-9]*s\" orgID" this works too.

I've open an issue to improve this see #2061