Number options

[teunbrand]

This PR aims to fix #376.

Briefly, it adds a new function number_options() that globally sets options for formatting numbers.
Subsequently, the label_*() functions use these options by default.

Rendered examples of the documentation:

devtools::load_all("~/packages/scales/")
#> ℹ Loading scales

# Default number formatting
x <- c(0.1, 1, 1000)
label_number()(x)
#> [1] "0.1"     "1.0"     "1 000.0"

# Now again with new options set
number_options(style_positive = "plus", decimal.mark = ",")
label_number()(x)
#> [1] "+0,1"     "+1,0"     "+1 000,0"

# The options are the argument names with a 'scales.'-prefix
options("scales.style_positive")
#> $scales.style_positive
#> [1] "plus"

# Resetting the options to their defaults
number_options()
label_number()(x)
#> [1] "0.1"     "1.0"     "1 000.0"

^{Created on 2024-10-03 with reprex v2.1.1}

[thomasp85]

Just to make sure. The prior behaviour when passing in NULL to all these arguments was to error, right? We are not breaking any expected behaviour here

[teunbrand]

In current scales, using prefix = NULL or suffix = NULL doesn't throw errors, it just doesn't add a prefix/suffix.
The big.mark, decimal.mark, style_positive and style_negative options did not accept NULL.

So I guess technically this PR might break prefix/suffix, but only if people go out of their way to write more verbose code than necessary.

If this is a problem, we can always make the argument a specific getOption() instead of internally resolving the defaults.

[thomasp85]

I think this is probably fine