loader and template not found error

[hnakamur]

Currently Environment.set_loader takes a function whose return value type F is Result<Option<String>, Error> + Send + Sync + 'static
(https://docs.rs/minijinja/1.0.7/minijinja/struct.Environment.html#method.set_loader) and F returns None when the template file is not found.

I think it is simpler to F is Result<String, Error> + Send + Sync + 'static and F returns an Error with ErrorKind::TemplateNotFound when the template file is not found.
Could you tell me what do you think?

[mitsuhiko]

I have been thinking a few times to change this, but this is a stable API now and it's not worth breaking the API for. The main benefit is that you get an automatic error message for the common "not found" case and it makes it easier to compose loaders in theory.

[hnakamur]

Alright, understood. Thanks for your explanation.