Percent encode set that encodes $ as %24?

[golddranks]

I'm using rust-url to percent encode the username and password in my postgresql://username:password@domain/dbname style URL. However, my password contains a special character $, and no one of the percent encoding sets provided by this crate seems to encode that.

$ is considered a "Reserved Character" ( https://tools.ietf.org/html/rfc3986#section-2.2 ), so I think it should be reasonable to encode it when it isn't used as a delimiter. I don't know of any current use of it as a delimiter in URLs, but the libpq that parses the URL complains about it, and accepts the password only as fully encoded.

Maybe there could be a STRICT_ENCODE_SET that would encode each of the reserved characters:

  reserved    = gen-delims / sub-delims

  gen-delims  = ":" / "/" / "?" / "#" / "[" / "]" / "@"

  sub-delims  = "!" / "$" / "&" / "'" / "(" / ")"
              / "*" / "+" / "," / ";" / "="

[SimonSapin]

Your crate can define its own encode set: https://docs.rs/url/1.5.0/url/macro.define_encode_set.html