How to detect free variable names in R functions [duplicate]

Answer 1

The codetools package has functions for this purpose, eg findGlobals

findGlobals(f, merge=FALSE)[['variables']]
# [1] "x"

if we redefine the function to have a named argument x then no variables are returned.

f2 <- function(x){
  x+1
}
findGlobals(f2, merge=FALSE)[['variables']]
# character(0)