Argument naming conventions in tidyverse



Are the rules used for naming arguments laid out somewhere ?

dplyr and purrr use dotted arguments (.arg), tidyr doesn't. dplyr names the first argument .data , tidyr uses data, purrr uses .x , but not always and sometimes even uses x.

I know that the tidyverse generally aims for consistency so I'm sure a lot of thoughts went into this, but I don't get it.

Another way to phrase my question: If I want to build functions that integrate well with the tidyverse, how should I name my arguments ?


Please see this thread:


Thanks Martin, it answers all my questions.

I'll summarize it as I understand it:

  • ... + NSE = possible argument conflicts, so it's a good idea to use dotted arguments in this case
  • in other cases don't use them, so they won't be there to conflict with the former, and less typing
  • Not everything is consistent, because of legacy and priorities. dplyr is the oldest tidyverse package so it has the most inconsistencies
  • Corollary is that to be up to date with current tidyverse, better to look at younger functions.

I suppose the following conventions though not exhaustive would be a good start (to add dot or not see previous bullet points):

  • data.frame (wide sense) input :data (don't use tbl or df)
  • if it's an element of a list, vector, or data.frame, it should be named x (y , z) if it takes a second element)
  • a list : l
  • predicate function : p (though some functions use predicate)
  • other function : f
  • list of functions : funs
  • an integer : n
  • an environment : env
  • an id column name (as string) : id
  • for these %operators%: x and y (%>% uses lhs and rhs but not newer ones)
  • type: type