Can we get path for functions & regex instead of strings?

[Keats]

Seeing https://blog.rust-lang.org/2019/04/11/Rust-1.34.0.html#custom-attributes-accept-arbitrary-token-streams maybe we can?

The next branch is using attr_literals already

[flappyBug]

As for the link you given, I think it's much better change length and range syntax to below:

// for length from 5 to 10 (10 is excluded)
#[validate(length(5..10))]   

// for length from 5 to 10 (10 is included)
#[validate(length(5..=10))]

// for length equal to 5
#[validate(length(5))]

[Keats]

Yes the issue wasn't clear :(

So right now for regex and functions, we take a path as a string, eg

validator/validator_derive/tests/regex.rs

Line 19 in 4b9fe39

#[validate(regex = "RE2")]

It would be neater if the user could write #[validate(regex = crate::users::USERNAME_REGEX)] for example so their IDE can help.

As for the length validator, that's interesting, I've created #76 to track it

[flappyBug]

I did some investigates on this. Here are what I found.

1. The range notation (e.g. 5..=10) can't parsed as meta. That's to say: If we want to support this syntax, we can't use Attribute::parse_meta or Attribute::interpret_meta to get the structure. I think we need to interpret token streams manually.

2. The syn crate don't support parse path as meta for now. But there is an issue tracking this. But we also could interpret the token streams manually.

3. I just saw that every validator has an optional code and message field. If we want to adapt the range syntax, instead of #[validate(length(5..=10, code="foo", message="bar"))], there is another choice: #[validate(length(5..10), code="foo", message="bar")], e.g. move the message and code to outer scope. What do you think?

[Keats]

1. Probably not worth it then imo, unless someone really wants it
2. Nice, going to be a change for a future version then.
3. That doesn't work I think since you can have multiple validators on a given field and each can have their own code/message