Looking as wasmer usage examples, I noticed that errors returned from a wasm function call not just have a message but also a stacktrace. No one complained yet, but I guess we want to serialize stacktraces into our error feedback.

The place to change would be [within instance.rs#execute_function()](https://github.com/tessi/wasmex/blob/f4894f78b9854c7256f9c7265add5e0187c3a546/native/wasmex/src/i

redbug doesn't seem to like tuple_size/1 in guards. It can be fixed in redbug itself or as a workaround in Rexbug, converting tuple_size(x) == y to is_tuple(x) and size(x) == y.

The former is probably the correct thing to do, the latter is probably much convenient to do right now.

This idea comes from some feedback on the Erlang forum:

Have you considered maybe supporting callbacks and/or notifications as well as Funs? e.g.

{callback, Mod :: atom(), Fun :: atom()}
{notify, Method :: call | cast | info, Pi

• Straightforward now that this is implemented: #30
• YAML lib: https://github.com/KamilLelonek/yaml-elixir
• Current parsers: pardall_markdown/metadata_parser

Proposed Solution

1. Parse YAML to Elixir, getting an Elixir map from the YAML FrontMatter string.
2. Then, feed the resulting e