Haskell has no dependent types, whence we can store only one type of value at each node of the data dependency graph. If in addition to Pandoc you want to extract the data in a machine-readable format, then set the alt type parameter of your Provenience actions accordingly and provide Representation instances for all your variable values. Each call to render or renderWith automatically invokes a call to representation.

In order to keep the dependency list of this package small beyond the dependencies of pandoc, we have omitted many useful instances. Add your own instances as you see fit, for example

instance Serializable a => Representation a ByteString where
    representation = toByteString

For spreadsheet-like representations,

• basic values become single cells in a single row,
• foldable structures of basic values become single columns,
• doubly-nested structures of basic values become proper tables.