99 lines
3.5 KiB
Rust
99 lines
3.5 KiB
Rust
|
use std::sync::OnceLock;
|
|||
|
|
|
|||
|
|
use icu_decimal::DecimalFormatter;
|
|||
|
|
use icu_decimal::input::Decimal;
|
|||
|
|
use icu_decimal::options::DecimalFormatterOptions;
|
|||
|
|
use icu_locale_core::Locale;
|
|||
|
|
|
|||
|
|
fn make_local_formatter() -> Option<DecimalFormatter> {
|
|||
|
|
let loc: Locale = sys_locale::get_locale()?.parse().ok()?;
|
|||
|
|
DecimalFormatter::try_new(loc.into(), DecimalFormatterOptions::default()).ok()
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
fn make_en_us_formatter() -> DecimalFormatter {
|
|||
|
|
#![allow(clippy::expect_used)]
|
|||
|
|
let loc: Locale = "en-US".parse().expect("en-US wasn't a valid locale");
|
|||
|
|
DecimalFormatter::try_new(loc.into(), DecimalFormatterOptions::default())
|
|||
|
|
.expect("en-US wasn't a valid locale")
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
fn formatter() -> &'static DecimalFormatter {
|
|||
|
|
static FORMATTER: OnceLock<DecimalFormatter> = OnceLock::new();
|
|||
|
|
FORMATTER.get_or_init(|| make_local_formatter().unwrap_or_else(make_en_us_formatter))
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// Format a u64 with locale-aware digit separators (e.g. "12345" -> "12,345"
|
|||
|
|
/// for en-US).
|
|||
|
|
pub fn format_with_separators(n: u64) -> String {
|
|||
|
|
formatter().format(&Decimal::from(n)).to_string()
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
fn format_si_suffix_with_formatter(n: u64, formatter: &DecimalFormatter) -> String {
|
|||
|
|
if n < 1000 {
|
|||
|
|
return formatter.format(&Decimal::from(n)).to_string();
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// Format `n / scale` with the requested number of fractional digits.
|
|||
|
|
let format_scaled = |n: u64, scale: u64, frac_digits: u32| -> String {
|
|||
|
|
let value = n as f64 / scale as f64;
|
|||
|
|
let scaled: u64 = (value * 10f64.powi(frac_digits as i32)).round() as u64;
|
|||
|
|
let mut dec = Decimal::from(scaled);
|
|||
|
|
dec.multiply_pow10(-(frac_digits as i16));
|
|||
|
|
formatter.format(&dec).to_string()
|
|||
|
|
};
|
|||
|
|
|
|||
|
|
const UNITS: [(u64, &str); 3] = [(1_000, "K"), (1_000_000, "M"), (1_000_000_000, "G")];
|
|||
|
|
let f = n as f64;
|
|||
|
|
for &(scale, suffix) in &UNITS {
|
|||
|
|
if (100.0 * f / scale as f64).round() < 1000.0 {
|
|||
|
|
return format!("{}{}", format_scaled(n, scale, 2), suffix);
|
|||
|
|
} else if (10.0 * f / scale as f64).round() < 1000.0 {
|
|||
|
|
return format!("{}{}", format_scaled(n, scale, 1), suffix);
|
|||
|
|
} else if (f / scale as f64).round() < 1000.0 {
|
|||
|
|
return format!("{}{}", format_scaled(n, scale, 0), suffix);
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
// Above 1000G, keep whole‑G precision.
|
|||
|
|
format!(
|
|||
|
|
"{}G",
|
|||
|
|
format_with_separators(((n as f64) / 1e9).round() as u64)
|
|||
|
|
)
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/// Format token counts to 3 significant figures, using base-10 SI suffixes.
|
|||
|
|
///
|
|||
|
|
/// Examples (en-US):
|
|||
|
|
/// - 999 -> "999"
|
|||
|
|
/// - 1200 -> "1.20K"
|
|||
|
|
/// - 123456789 -> "123M"
|
|||
|
|
pub fn format_si_suffix(n: u64) -> String {
|
|||
|
|
format_si_suffix_with_formatter(n, formatter())
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
#[cfg(test)]
|
|||
|
|
mod tests {
|
|||
|
|
use super::*;
|
|||
|
|
|
|||
|
|
#[test]
|
|||
|
|
fn kmg() {
|
|||
|
|
let formatter = make_en_us_formatter();
|
|||
|
|
let fmt = |n: u64| format_si_suffix_with_formatter(n, &formatter);
|
|||
|
|
assert_eq!(fmt(0), "0");
|
|||
|
|
assert_eq!(fmt(999), "999");
|
|||
|
|
assert_eq!(fmt(1_000), "1.00K");
|
|||
|
|
assert_eq!(fmt(1_200), "1.20K");
|
|||
|
|
assert_eq!(fmt(10_000), "10.0K");
|
|||
|
|
assert_eq!(fmt(100_000), "100K");
|
|||
|
|
assert_eq!(fmt(999_500), "1.00M");
|
|||
|
|
assert_eq!(fmt(1_000_000), "1.00M");
|
|||
|
|
assert_eq!(fmt(1_234_000), "1.23M");
|
|||
|
|
assert_eq!(fmt(12_345_678), "12.3M");
|
|||
|
|
assert_eq!(fmt(999_950_000), "1.00G");
|
|||
|
|
assert_eq!(fmt(1_000_000_000), "1.00G");
|
|||
|
|
assert_eq!(fmt(1_234_000_000), "1.23G");
|
|||
|
|
// Above 1000G we keep whole‑G precision (no higher unit supported here).
|
|||
|
|
assert_eq!(fmt(1_234_000_000_000), "1,234G");
|
|||
|
|
}
|
|||
|
|
}
|