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.
obj_sum also includes the size of the object if is_s3_vector
is TRUE.
Usage
obj_sum(x)
type_sum(x)
is_vector_s3(x)
Arguments
x
an object to summarise. Generally only methods of atomic vectors
and variants have been implemented.