Options should only affect side-effects, not computation

[hadley]

• print() + options(digits, width)

• install.packages() + options(repos)

• readr::read_cs(), show_progress() and options(readr.show_progress = FALSE)

• scale_colour_continuous() and getOption("ggplot2.continuous.colour", default = "gradient"))

• crayon/cli

• usethis::use_description_defaults()

Counter examples:

• lubridate::wday(): week_start = getOption("lubridate.week.start", 7)
• stringsAsFactors