问在没有全局范围的情况下将方法添加到R列表中

EN

requireNamespace("flifo")

cards       <- letters[1:5]
deck_loop   <- flifo::fifo()
deck_purrr  <- flifo::fifo()

# Looping works correctly   
for( card in cards ) {
  flifo::push(deck_loop, card)
}
message("Deck size: ", as.integer(flifo::size(deck_loop) / 96), " cards")
# Returns: "Deck size: 5 cards"

# This version of calling purrr::walk() doesn't work.
purrr::walk(cards, function(card) flifo::push(deck_purrr, card))
message("Deck size: ", as.integer(flifo::size(deck_purrr) / 96), " cards")
# Returns: "Deck size: 0 cards"

l3 <- list()
fx3 <- function(a) {
  # l3[[length(l3) + 1L]] <- a # Won't work b/c it's not a global assignment
  l3[[length(l3) + 1L]] <<- a
}
purrr::walk(11:15, function( x ) fx3(x))

deck_rstack  <- rstack::stack$new()
purrr::walk(cards, function(card) deck_rstack$push(card))
message("Deck size: ", deck_rstack$size(), " cards")