If, in teaching folks about the magrittr pipe operator,
%>%, you’re looking for an in-the-wild example of deeply nested functions, our miner package (for connecting R to Minecraft, developed at the ROpenSci 2017 Unconference) has a good one:
setNames(data.frame( do.call(rbind, sapply( X = sub(",", "|", strsplit(string, '|', fixed = TRUE)[], fixed=TRUE), FUN = strsplit, split = '|', fixed=TRUE, USE.NAMES = FALSE)), stringsAsFactors=FALSE), colnames)
This turns a character string like
"121,hello everyone|4734,R mc_plot()" into a data frame like
## player message ## 1 121 hello everyone ## 2 4734 R mc_plot()
That’s six functions deep:
strsplit %>% sub %>% sapply %>% do.call %>% data.frame %>% setNames.