Only suggest cli/crayon/fansi

[hadley]

(Would also need to do the same in pillar)

These are moderately heavy dependencies so it would be nice to make them optional.

I would be cautiously in favour of creating a new package that we could import that suggested cli/crayon/fansi but if weren't available provided a base fallback (i.e. no colour). If you wanted to go that route, I think the best place to start would be a review of all the cli/crayon/fansi functionality currently used in tibble + pillar.

[krlmlr]

Would that new package print a startup message when the suggested packages are not available? Otherwise we might have a tough time debugging problems caused by the parallel code paths.

[hadley]

The parallel code path would do nothing, so I don't think debugging would be hard.

[krlmlr]

I'm not sure. Example: word wrapping. If fansi is available, we use fansi::strwrap_ctl(), otherwise strwrap(). Would we implement it like this?

fallback_strwrap <- function(...) {
  if (color_available()) {
    fansi::strwrap_ctl(...)
  } else {
    strwrap()
  }
}

Perhaps I don't understand what the new package is supposed to handle.

[hadley]

Right - if we're not using colour we don't need special handling for wrapping strings.

The goal is to provide a single package that we can import whenever we want to use colour, but does not import any packages in turn.

[krlmlr]

Minimize cli imports first (convert to Suggests).

[krlmlr]

Then, cli could be used as proxy/shim package.

[krlmlr]

The wrapper interface should use paste0() instead of paste():

> crayon::blue("a", "b", "c")
[1] "\033[34ma b c\033[39m"

Model after usethis::proj_sitrep() .

[krlmlr]

We can't remove fansi yet, only after really removing trunc_mat().