diff options
Diffstat (limited to 'src/format.rs')
| -rw-r--r-- | src/format.rs | 103 |
1 files changed, 94 insertions, 9 deletions
diff --git a/src/format.rs b/src/format.rs index ab0e856f..6a6b908e 100644 --- a/src/format.rs +++ b/src/format.rs @@ -25,7 +25,7 @@ impl<'a> TryFrom<Option<&'a str>> for Placeholder<'a> { } } -#[derive(Debug, PartialEq)] +#[derive(Debug, Copy, Clone, PartialEq)] pub enum Align { Left, Center, @@ -165,21 +165,78 @@ pub fn parse_line_number_format<'a>( format_data } +pub trait CenterRightNumbers { + fn width_for_center_right(&self) -> usize; +} + +impl CenterRightNumbers for &str { + fn width_for_center_right(&self) -> usize { + // Disables the center-right formatting and aligns strings center-left + usize::MAX + } +} + +impl CenterRightNumbers for String { + fn width_for_center_right(&self) -> usize { + self.as_str().width_for_center_right() + } +} + +impl<'a> CenterRightNumbers for &std::borrow::Cow<'a, str> { + fn width_for_center_right(&self) -> usize { + self.as_ref().width_for_center_right() + } +} + +impl CenterRightNumbers for usize { + fn width_for_center_right(&self) -> usize { + // log10 for integers is only in nightly and this is faster than + // casting to f64 and back. + let mut n = *self; + let mut len = 1; + loop { + if n <= 9 { + break len; + } + len += 1; + n /= 10; + } + } +} + // Note that in this case of a string `s`, `precision` means "max width". // See https://doc.rust-lang.org/std/fmt/index.html -pub fn pad(s: &str, width: usize, alignment: &Align, precision: Option<usize>) -> String { - match precision { +pub fn pad<T: std::fmt::Display + CenterRightNumbers>( + s: T, + width: usize, + alignment: Align, + precision: Option<usize>, +) -> String { + let center_left_to_right_align_fix = || { + let q = s.width_for_center_right(); + width > q && (width % 2 != q % 2) + }; + let space = if alignment == Align::Center && center_left_to_right_align_fix() { + " " + } else { + "" + }; + let mut result = match precision { None => match alignment { - Align::Left => format!("{0:<1$}", s, width), - Align::Center => format!("{0:^1$}", s, width), - Align::Right => format!("{0:>1$}", s, width), + Align::Left => format!("{0}{1:<2$}", space, s, width), + Align::Center => format!("{0}{1:^2$}", space, s, width), + Align::Right => format!("{0}{1:>2$}", space, s, width), }, Some(precision) => match alignment { - Align::Left => format!("{0:<1$.2$}", s, width, precision), - Align::Center => format!("{0:^1$.2$}", s, width, precision), - Align::Right => format!("{0:>1$.2$}", s, width, precision), + Align::Left => format!("{0}{1:<2$.3$}", space, s, width, precision), + Align::Center => format!("{0}{1:^2$.3$}", space, s, width, precision), + Align::Right => format!("{0}{1:>2$.3$}", space, s, width, precision), }, + }; + if !space.is_empty() { + result.pop(); } + result } #[cfg(test)] @@ -187,6 +244,34 @@ mod tests { use super::*; #[test] + fn test_width_trait() { + dbg!("asdf".to_string().width_for_center_right()); + dbg!(3_usize.width_for_center_right()); + dbg!(99_999_usize.width_for_center_right()); + dbg!(100_000_usize.width_for_center_right()); + dbg!(100_003_usize.width_for_center_right()); + dbg!(700_003_usize.width_for_center_right()); + dbg!(999_999_usize.width_for_center_right()); + dbg!(1_000_000_usize.width_for_center_right()); + dbg!(1_000_001_usize.width_for_center_right()); + dbg!(9876654321_usize.width_for_center_right()); + } + + #[test] + fn test_pad_center_align() { + for i in (1..1001_usize) + .into_iter() + .filter(|&i| i < 20 || (i > 90 && i < 120) || i > 990) + { + println!( + "string: │{}│ num: │{}│", + pad(i.to_string(), 4, Align::Center, None), + pad(i, 4, Align::Center, None), + ); + } + } + + #[test] fn test_placeholder_regex() { let regex = make_placeholder_regex(&["placeholder"]); assert_eq!( |