Formatters

Formatters describe how to take a Record and convert it into properly formatted string. Currently, there are two types of Formatters.

1. DefaultFormatter: use a simple template string format to map keys in the Record to places in the resulting string. (ie: DefaultFormatter("[{date} | {level} | {name}]: {msg}")

2. JsonFormatter: builds an appropriate formatted Dict from the Record in order to use JSON.json(dict) to produce the resulting string.

You should only need to write a custom Formatter type if you're needing to produce very specific string formats regardless of the Record type being used. For example, we may want a CSVFormatter which always writes logs in a CSV Format.

If you just need to customize the behaviour of an existing Formatter to a specific Record type then you should simply overload the format method for that Formatter.

Example)

function Memento.format(fmt::DefaultFormatter, rec::MyRecord)
    ...
end