lionel-

remap <- function(.x, .f, ...) {
  .f <- lowliner:::as_function(.f)

  if (inherits(.f, "fseq")) {
    # Handle magrittr's functional sequences
    f_env <- environment(.f)
    f_env$`_function_list` <- map(f_env$`_function_list`, ~ {
      env <- new.env(parent = environment(.))
      environment(.) <- env
      .

lionel-

set_groups <- function(.d, .cols = NULL) {
  stopifnot(is.data.frame(.d))
  if (is.null(.cols)) {
    return(group_by_(.d, .dots = list()))
  }

  if (is.numeric(.cols)) {
    .cols <- names(.d)[.cols]
  }
  .cols %>% map_call(dplyr::group_by_, .data = .d)

lionel-

  ###  Install monad-aware magrittr

devtools::dev_mode(TRUE)
devtools::install_github("lionel-/magrittr", ref = "monads")


  ###  Monadic Infrastructure

bind <- function(x, fun, ...) {
  UseMethod("bind")

lionel-

library("rlang")


#' @import rlang
`%>%` <- function(x, y) {
  lhs <- rlang:::captureArg(x)
  lhs_value <- eval_bare(lhs$expr, lhs$env)

  

lionel-

depend <- function(..., character.only = FALSE) {
  # Mimic library()'s UI
  if (character.only) {
    packages <- c(...)
  } else {
    packages <- substitute(c(...))[-1]
    if (!all(vapply(packages, is.symbol, logical(1)))) {
      stop("Can't supply expressions if `character.only` is FALSE")
    }

lionel-

# Actually does not work because quosured magrittr pronouns are not
# evaluated in the right environment


library("magrittr")
library("rlang")

# Anticipate renaming of `quo_is_lang()` in rlang
quo_is_call <- quo_is_lang

lionel-

truncate_len <- function(x, n) {
  if (length(x) < n) {
    stop("Can't truncate vector to the given length because it is already shorter")
  }
  x[seq_len(n)]
}
truncate_along <- function(x, y) {
  truncate_len(x, length(y))

lionel-

# Simple DT wrapper
summarise <- function(data, j, by) {
  data <- data.table::as.data.table(data)
  data[
    i = ,
    j = eval(substitute(j)),
    by = eval(substitute(by))
  ]
}

lionel-

# The general idea is to supply a recoding specification through a
# data frame of keys and values. They keys are a generalisation of
# names, they can be any type.


keys <- function(key, value) {
  tibble::tibble(.key = key, .value = value)
}
dribbleys <- function(...) {
  tibble::tribble(~ .key, ~ .value, ...)

lionel-

makeDelayedBinding <- function(sym,
                               expr,
                               eval.env = parent.frame(1),
                               assign.env = parent.frame(1)) {
  expr <- substitute(expr)

  value <- NULL
  forced <- FALSE

  forceDelayed <- function() {