Feature - wrap at a specific character

[Moohan]

We were discussing label_wrap in a recent training session and it was mentioned that it would be useful to 'wrap at' a specific character, rather than just at a specific width.

I think label_wrap could be expanded to include this behaviour or a new function added e.g.

label_wrap_at <- function(at = "\\s", replace = TRUE) {
  force(at)

  function(x) {
    gsub(glue::glue("({at})"), ifelse(replace, "\n", "\\1\n"), x)
  }
}

x <- c(
  "this is a long label",
  "this is another long label",
  "this a label this is even longer"
)
demo_discrete(x)
demo_discrete(x, labels = label_wrap_at())
demo_discrete(x, labels = label_wrap_at("a", replace = FALSE))
demo_discrete(x, labels = label_wrap_at("[aeiou]", replace = FALSE))
demo_discrete(x, labels = label_wrap_at("label", replace = FALSE))

Wrapping at a space is the obvious use case, and it also makes sense to replace the space when doing this, other use cases might be to replace 'at' a given character or word in which case it would make less sense to replace the character.

[thomasp85]

I have a hard time envisioning how this can be useful in a general sense, since characters can appear wherever in a label and this create very inconvenient wrapping. As such I don't think it is a good fit for scales