Add default handling for refiners
Currently, refiners will fail when applied to any node for which their implementation is not specified. This can be avoided by adding a default case [#f [(λ (n) #f)]]
, but this shouldn't be necessary.
Check for the presence of a #f
case, and if absent, supply the above default implementation.
Maybe also add a #:no-default
parameter to disable the functionality if desired? I don't know why it would ever be beneficial to leave it out, though.