Performance / internals
data.table and Rcpp C++ kernels, removing the runtime
dependencies on dplyr, magrittr, and
rlang.cpp_weighted_mean,
cpp_rev_cumsum_by_group, cpp_fdtr_wtilde2, and
cpp_feS_delta for the per-row group computations that
previously used dplyr::group_by() +
dplyr::lead() / dplyr::lag().Internals