#' Extract Predictor Names from Formula or Terms

#'

#' `all.vars` returns all variables used in a formula. This

#'  function only returns the variables explicitly used on the

#'  right-hand side (i.e., it will not resolve dots unless the

#'  object is terms with a data set specified).

#' @param object A model formula or [stats::terms()]

#'  object.

#' @param ... Arguments to pass to [all.vars()]

#' @return A character vector of names

#' @export

#' @examples

#' form_pred(y ~ x + z)

#' form_pred(terms(y ~ x + z))

#'

#' form_pred(y ~ x + log(z))

#' form_pred(log(y) ~ x + z)

#'

#' form_pred(y1 + y2 ~ x + z)

#' form_pred(log(y1) + y2 ~ x + z)

#'

#' # will fail:

#' # form_pred(y ~ .)

#'

#' form_pred(terms(mpg ~ (.)^2, data = mtcars))

#' form_pred(terms( ~ (.)^2, data = mtcars))

#' @importFrom stats terms

form_pred <- function(object, ...) {

  }

  ## If there is something on the lhs of the formula,

  ## remove it and get vars

  }

}