old.opt <- options(prompt = ">>", continue = " |")

>>a + b + fun(x + funz(matrix_over[25, 32]) + transform(iris, x = Sepal.Width * 
 |    3)/the_donkey_ate_a_carrot %in% {
 |    paste0(match(letter, LETTERS), c("hello there"))
 |})

[1] ">>a + b + fun(x + funz(matrix_over[25, 32]) + transform(iris, x = Sepal.Width * \n |    3)/the_donkey_ate_a_carrot %in% {\n |    paste0(match(letter, LETTERS), c(\"hello there\"))\n |})\n"

a + b + fun(x + funz(matrix_over[25, 32]) + transform(iris, x = Sepal.Width * 
        3)/the_donkey_ate_a_carrot %in% {
        paste0(match(letter, LETTERS), c("hello there"))
    })

[1] "    a + b + fun(x + funz(matrix_over[25, 32]) + transform(iris, x = Sepal.Width * \n        3)/the_donkey_ate_a_carrot %in% {\n        paste0(match(letter, LETTERS), c(\"hello there\"))\n    })\n"

a + b + fun(x + funz(matrix_over[25, 32]) + transform(iris, x = Sepal.Width * 
        3)/the_donkey_ate_a_carrot %in% {...

[1] "    a + b + fun(x + funz(matrix_over[25, 32]) + transform(iris, x = Sepal.Width * \n        3)/the_donkey_ate_a_carrot %in% {...\n"

vetr:::dep_oneline(quote(1 + 1 + 3), 10)

vetr:::dep_oneline(quote(1 + 1 + 3), "hello")

Internal Error: arg max_chars and keep_at_end must be positive

Warning in vetr:::dep_oneline(quote(1 + 1 + 3), "hello") :
  NAs introduced by coercion
Error in vetr:::dep_oneline(quote(1 + 1 + 3), "hello") : 
  Internal Error: arg max_chars and keep_at_end must be positive