Dump a value into YAML

[lquerel]

We already have a tojson filter to output a value in JSON format, but we don’t have a filter for YAML output. Some people have expressed this need.

[unpervertedkid]

@lquerel , can I pick this up?

[lquerel]

@unpervertedkid Yes. Thank you

[unpervertedkid]

@lquerel , for me to understand how to properly go on with this, kindly help point me on the following:

1. An example of usage of the current tojson filter or how I can create a simple example usage to get the gist of the current implementation.
2. I see that there is a filter in weaver_forge/src/filter.rs. Is that the toJson filter we are referring to?

If you have any other pointers in the docs or relevant information to get me started on this would be really appreciated.
Thanks.

[lquerel]

@unpervertedkid You can add the toyaml filter in crates/weaver_forge/src/extensions/util.rs. The signature of the filter should be something like fn to_yaml(value: Value) -> Result<Value, minijinja::Error>. We also have to register this function in the add_filters (same file) with something like env.add_filter("toyaml", to_yaml). In the repo of minijinja there is the implementation of the tojson filter so you can probably adapt the code from there. See https://github.com/mitsuhiko/minijinja/blob/4249fb3f423eb076317db542f08a00a1fcec39c3/minijinja/src/filters.rs#L1059

You also have to add a unit test. Thanks

[unpervertedkid]

@lquerel , is it important to preserve ordering when converting to yaml?