Fool's five

fools_five.R

f <- function(...) {
  function(df) with(df, ...)
}

footate <- function(.data, ...) {
  dots <- list(...)

  for (column in names(dots)) {
    .data[[column]] <- dots[[column]](.data)
  }

  return (.data)
}

foolter <-function(.data, ...) {
  dots <- list(...)


  indexes <-
    Reduce(function(a, b) a & b(.data),
           init = dots[[1]](.data),
           x = dots)

  return (.data[indexes, ])
}


foolter(mtcars, f(cyl >= 6 & am == 1))

library(microbenchmark)

microbenchmark(
  footate(mtcars, foo = f(mpg * cyl)),
  mutate(mtcars, foo = mpg * cyl))

microbenchmark(
  filter(mtcars, cyl >= 6 & am == 1),
  foolter(mtcars, f(cyl >= 6 & am == 1))
)

## mixing local + global state
footate(mtcars, foo = f(mpg * cyl * a_global))

foolter(mtcars, f(cyl >= 6 & am == 1 & a_global))