vendor/concolor/src/color/choice.rs

   1 use std::sync::atomic::{AtomicUsize, Ordering};
   2
   3 #[derive(Debug)]
   4 pub(crate) struct AtomicChoice(AtomicUsize);
   5
   6 impl AtomicChoice {
   7     pub(crate) const fn new() -> Self {
   8         Self(AtomicUsize::new(Self::from_choice(
   9             crate::ColorChoice::Auto,
  10         )))
  11     }
  12
  13     pub(crate) fn get(&self) -> crate::ColorChoice {
  14         let choice = self.0.load(Ordering::SeqCst);
  15         Self::to_choice(choice).unwrap()
  16     }
  17
  18     #[cfg(feature = "api_unstable")]
  19     pub(crate) fn set(&self, choice: crate::ColorChoice) {
  20         let choice = Self::from_choice(choice);
  21         self.0.store(choice, Ordering::SeqCst);
  22     }
  23
  24     const fn from_choice(choice: crate::ColorChoice) -> usize {
  25         match choice {
  26             crate::ColorChoice::Auto => 0,
  27             crate::ColorChoice::AlwaysAnsi => 1,
  28             crate::ColorChoice::Always => 2,
  29             crate::ColorChoice::Never => 3,
  30         }
  31     }
  32
  33     const fn to_choice(choice: usize) -> Option<crate::ColorChoice> {
  34         match choice {
  35             0 => Some(crate::ColorChoice::Auto),
  36             1 => Some(crate::ColorChoice::AlwaysAnsi),
  37             2 => Some(crate::ColorChoice::Always),
  38             3 => Some(crate::ColorChoice::Never),
  39             _ => None,
  40         }
  41     }
  42 }
  43
  44 impl Default for AtomicChoice {
  45     fn default() -> Self {
  46         Self::new()
  47     }
  48 }
  49
  50 #[cfg(test)]
  51 mod test {
  52     use super::*;
  53
  54     #[test]
  55     fn choice_serialization() {
  56         let expected = vec![
  57             crate::ColorChoice::Auto,
  58             crate::ColorChoice::AlwaysAnsi,
  59             crate::ColorChoice::Always,
  60             crate::ColorChoice::Never,
  61         ];
  62         let values: Vec<_> = expected
  63             .iter()
  64             .cloned()
  65             .map(AtomicChoice::from_choice)
  66             .collect();
  67         let actual: Vec<_> = values
  68             .iter()
  69             .cloned()
  70             .map(AtomicChoice::to_choice)
  71             .flatten()
  72             .collect();
  73         assert_eq!(expected, actual);
  74     }
  75 }