[Feature request] Allow forward slash (/) to be optionally escaped in patterns

[comex]

Describe your feature request

Many languages use / to indicate the start and end of a regular expression, and thus require any forward slashes within the pattern to be escaped as \/.

ripgrep does not need to explicitly delimit regexes, and does not treat / as special. But sometimes habit leads me to mistakenly type \/ anyway. This produces an error:

regex parse error:
    \/foo
    ^^
error: unrecognized escape sequence

Fair enough. But given ripgrep's status as an interactive tool, it would be nice if it would just Do What I Mean, perhaps warning about the unnecessary escape but then proceeding, rather than making me go back and edit the command.

I tested various other regular expression APIs and tools that don't use / as a delimiter: Python re, PCRE, GNU grep, and BSD grep on macOS. All of these accepted \/ (with no warning) and treated it as /. (Most of those seemed to allow unnecessary backslash escapes of arbitrary characters; Python allowed it for characters other than letters and numbers. Personally I'd prefer a more conservative approach that only allows it for /.)

[BurntSushi]

This is better tracked here: rust-lang/regex#501

While I suppose ripgrep could allow this independently of what the regex engine does, it would probably be more trouble than it's worth.

[comex]

Aha.