lightningcss/values/
number.rs

1//! CSS number values.
2
3use super::angle::impl_try_from_angle;
4use super::calc::Calc;
5use crate::error::{ParserError, PrinterError};
6use crate::printer::Printer;
7use crate::traits::private::AddInternal;
8use crate::traits::{Map, Op, Parse, Sign, ToCss, Zero};
9use cssparser::*;
10
11/// A CSS [`<number>`](https://www.w3.org/TR/css-values-4/#numbers) value.
12///
13/// Numbers may be explicit or computed by `calc()`, but are always stored and serialized
14/// as their computed value.
15pub type CSSNumber = f32;
16
17impl<'i> Parse<'i> for CSSNumber {
18  fn parse<'t>(input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i, ParserError<'i>>> {
19    match input.try_parse(Calc::parse) {
20      Ok(Calc::Value(v)) => return Ok(*v),
21      Ok(Calc::Number(n)) => return Ok(n),
22      // Numbers are always compatible, so they will always compute to a value.
23      Ok(_) => return Err(input.new_custom_error(ParserError::InvalidValue)),
24      _ => {}
25    }
26
27    let number = input.expect_number()?;
28    Ok(number)
29  }
30}
31
32impl ToCss for CSSNumber {
33  fn to_css<W>(&self, dest: &mut Printer<W>) -> Result<(), PrinterError>
34  where
35    W: std::fmt::Write,
36  {
37    let number = *self;
38    if number != 0.0 && number.abs() < 1.0 {
39      let mut s = String::new();
40      cssparser::ToCss::to_css(self, &mut s)?;
41      if number < 0.0 {
42        dest.write_char('-')?;
43        dest.write_str(s.trim_start_matches("-0"))
44      } else {
45        dest.write_str(s.trim_start_matches('0'))
46      }
47    } else {
48      cssparser::ToCss::to_css(self, dest)?;
49      Ok(())
50    }
51  }
52}
53
54impl std::convert::Into<Calc<CSSNumber>> for CSSNumber {
55  fn into(self) -> Calc<CSSNumber> {
56    Calc::Value(Box::new(self))
57  }
58}
59
60impl std::convert::From<Calc<CSSNumber>> for CSSNumber {
61  fn from(calc: Calc<CSSNumber>) -> CSSNumber {
62    match calc {
63      Calc::Value(v) => *v,
64      Calc::Number(n) => n,
65      _ => unreachable!(),
66    }
67  }
68}
69
70impl AddInternal for CSSNumber {
71  fn add(self, other: Self) -> Self {
72    self + other
73  }
74}
75
76impl Op for CSSNumber {
77  fn op<F: FnOnce(f32, f32) -> f32>(&self, to: &Self, op: F) -> Self {
78    op(*self, *to)
79  }
80
81  fn op_to<T, F: FnOnce(f32, f32) -> T>(&self, rhs: &Self, op: F) -> T {
82    op(*self, *rhs)
83  }
84}
85
86impl Map for CSSNumber {
87  fn map<F: FnOnce(f32) -> f32>(&self, op: F) -> Self {
88    op(*self)
89  }
90}
91
92impl Sign for CSSNumber {
93  fn sign(&self) -> f32 {
94    if *self == 0.0 {
95      return if f32::is_sign_positive(*self) { 0.0 } else { -0.0 };
96    }
97    self.signum()
98  }
99}
100
101impl Zero for CSSNumber {
102  fn zero() -> Self {
103    0.0
104  }
105
106  fn is_zero(&self) -> bool {
107    *self == 0.0
108  }
109}
110
111impl_try_from_angle!(CSSNumber);
112
113/// A CSS [`<integer>`](https://www.w3.org/TR/css-values-4/#integers) value.
114pub type CSSInteger = i32;
115
116impl<'i> Parse<'i> for CSSInteger {
117  fn parse<'t>(input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i, ParserError<'i>>> {
118    // TODO: calc??
119    let integer = input.expect_integer()?;
120    Ok(integer)
121  }
122}
123
124impl ToCss for CSSInteger {
125  fn to_css<W>(&self, dest: &mut Printer<W>) -> Result<(), PrinterError>
126  where
127    W: std::fmt::Write,
128  {
129    cssparser::ToCss::to_css(self, dest)?;
130    Ok(())
131  }
132}
133
134impl Zero for CSSInteger {
135  fn zero() -> Self {
136    0
137  }
138
139  fn is_zero(&self) -> bool {
140    *self == 0
141  }
142}
lightningcss/values/number.rs

lightningcss/values/
number.rs
