write_mutated_pkg: replacing lines instead of writing new lines?

[sckott]

Right now write_mutated_pkg makes completely new R files, and writes the mutated fxns into those files. Maybe copy over R files from original location, and use line number/column position to replace lines - so that roxygen tags/constants/etc are retained as those things could affect outcomes

[sckott]

this is complicated. the way R parses functions, it doesn't maintain the same number of lines, e.g.,

remotes::install_github("ropenscilabs/astr")
library(astr)
foo <- function(x = NULL) {
  if (!is.null(x)) x * 10
  return(x)
}
w = ast_decompose(foo)
fun = ast_recompose(w)
cat(fun)
#> function (x = NULL)
#> {
#>     if (!is.null(x))
#>         x * 10
#>     return(x)
#> }

In this example, the if statement is all on one line, which isn't that uncommon. So the recomposed function adds an additional line, with the if statement over 2 lines.

If we wanted to re-insert mutated functions into the original file structure they were pulled from, we'd need to account for these additional lines and push any further lines down.

[sckott]

coming back to later