This is the documented behavior since r35262 (2005), from ?format > If x is a list, the result is a character vector obtained by applying > format.default(x, ...) to each element of the list
One consequence is that we can't add "nice" printing methods for list-of-object columns in data.frames: https://github.com/eddelbuettel/rprotobuf/issues/109 library(RProtoBuf) person_desc <- P("tutorial.Person") DF <- data.frame(id = 1:2) DF$person = list(person_desc$new(name = "Me"), person_desc$new(name = "You", email = "y...@u.com")) DF # id person # 1 1 <S4 class ‘Message’ [package “RProtoBuf”] with 2 slots> # 2 2 <S4 class ‘Message’ [package “RProtoBuf”] with 2 slots> ^ from format.default, with option to make it more informative One assumes that at this point, there are back-compatibility concerns since this is the documented behavior. Is there no other option than to make the 'person' column itself an S3 class with an associated format method? ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
