Get the unique set of namespaces specified in an R script

get_namespaces.R

get_namespaces <- function(file, as_imports=FALSE) {
  require(stringi)
  require(dplyr)
  
  nm <- readLines(file) %>% 
    stringi::stri_extract_all(regex='[\\w_.]+::[\\w_.]+') %>% 
    unlist %>% 
    setdiff(NA) %>% 
    sort
  
  if(as_imports) {
    strsplit(nm, '::') %>% 
      do.call(rbind.data.frame, .) %>% 
      setNames(c('ns', 'fun')) %>% 
      group_by(ns) %>% 
      summarise(
        string = sprintf("#' @importFrom %s %s", 
                         cur_group(), paste(fun, collapse=' ')),
        .groups='drop'
      ) %>% 
      pull(string) %>% 
      cat(sep='\n')
  } else {
    nm
  }
}