type_sum() gives a brief summary of object type. Objects that commonly
occur in a data frame should return a string with four or less characters.
For most inputs, the argument is forwarded to
obj_sum() also includes the size of the object if
It should always return a string (a character vector of length one).
size_sum() is called by
obj_sum() to format the size of the object.
It should always return a string (a character vector of length one),
it can be an empty string
"" to omit size information,
this is what the default method does for scalars.
type_sum(x) obj_sum(x) size_sum(x)
an object to summarise. Generally only methods of atomic vectors and variants have been implemented.
When formatting a pillar,
type_sum() will be called on a slice of the column vector.
The formatted type should only depend on the type and not on the data,
to avoid confusion.