InternalMethods package:base R Documentation _I_n_t_e_r_n_a_l _G_e_n_e_r_i_c _F_u_n_c_t_i_o_n_s _D_e_s_c_r_i_p_t_i_o_n: Many R-internal functions are _generic_ and allow methods to be written for. _D_e_t_a_i_l_s: The following primitive and internal functions are _generic_, i.e., you can write 'methods' for them: '[', '[[', '$', '[<-', '[[<-', '$<-', 'length', 'length<-', 'dimnames', 'dimnames<-', 'dim', 'dim<-', 'names', 'names<-', 'levels<-', 'c', 'unlist', 'cbind', 'rbind', 'as.character', 'as.complex', 'as.double', 'as.integer', 'as.logical', 'as.raw', 'as.vector', 'is.array', 'is.matrix', 'is.na', 'is.nan', 'is.numeric', 'rep' and 'seq.int' (which dispatches methods for '"seq"'). In addition, 'is.name' is a synonym for 'is.symbol' and dispatches methods for the latter. Note that all of the group generic functions are also internal/primitive and allow methods to be written for them. '.S3PrimitiveGenerics' is a character vector listing the primitives which are internal generic and not group generic. Currently 'as.vector', 'cbind', 'rbind' and 'unlist' are the internal non-primitive functions which are internally generic. For efficiency, internal dispatch only occurs on _objects_, that is those for which 'is.object' returns true. _S_e_e _A_l_s_o: 'methods' for the methods which are available.