Push an element to the back
Examples
s <- as_flexseq(letters[1:3])
s2 <- push_back(s, "d")
s2
#> FingerTree <size=4, named=no>
#> monoids: none
#>
#> [[1]]
#> [1] "a"
#>
#> [[2]]
#> [1] "b"
#>
#> [[3]]
#> [1] "c"
#>
#> [[4]]
#> [1] "d"
#>
n <- as_flexseq(list(two = 2, three = 3))
new_el <- 4
names(new_el) <- "four"
push_back(n, new_el)
#> FingerTree <size=3, named=yes>
#> monoids: none
#>
#> $two
#> [1] 2
#>
#> $three
#> [1] 3
#>
#> $four
#> four
#> 4
#>