css 0.0.22

A crate that uses the cssparser and selectors crates to provide a domain model for CSS Stylesheets. Intended to allow effective minification of CSS and CSS transformations such as autoprefixing and removal by other crates
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// This file is part of css. It is subject to the license terms in the COPYRIGHT file found in the top-level directory of this distribution and at https://raw.githubusercontent.com/lemonrock/css/master/COPYRIGHT. No part of predicator, including this file, may be copied, modified, propagated, or distributed except according to the terms contained in the COPYRIGHT file.
// Copyright © 2017 The developers of css. See the COPYRIGHT file in the top-level directory of this distribution and at https://raw.githubusercontent.com/lemonrock/css/master/COPYRIGHT.


#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct Ratio
{
	width: u32,
	height: u32,
}

impl ToCss for Ratio
{
	fn to_css<W: fmt::Write>(&self, dest: &mut W) -> fmt::Result
	{
		self.width.to_css(dest)?;
		dest.write_str("/")?;
		self.height.to_css(dest)
	}
}

impl Parse for Ratio
{
	fn parse<'i, 't>(_context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<Self, ParseError<'i, CustomParseError<'i>>>
	{
		let width = input.expect_integer()?;
		if width <= 0
		{
			return Err(ParseError::Custom(CustomParseError::RatioNumeratorCanNotBeNegativeOrZero(width)))
		}
		
		input.expect_delim('/')?;
		
		let height = input.expect_integer()?;
		if height <= 0
		{
			return Err(ParseError::Custom(CustomParseError::RatioDivisorCanNotBeNegativeOrZero(width)))
		}
		
		Ok(Self::new(width as u32, height as u32))
	}
}

impl Ratio
{
	/// This method will simplify the ratio, so creating smaller numbers in resultant CSS
	#[inline(always)]
	pub fn new(width: u32, height: u32) -> Self
	{
		debug_assert!(width != 0, "width can not be zero");
		debug_assert!(height != 0, "height can not be zero");
		
		// Euclid's algorithm for finding the greatest common divisor
		#[inline(always)]
		fn greatestCommonDivisorByEuclidsAlgorithm(nominator: u32, denominator: u32) -> u32
		{
			let mut x = nominator;
			let mut y = denominator;
			while y != 0
			{
				let t = y;
				y = x % y;
				x = t;
			}
			x
		}
		let greatestCommonDivisor = greatestCommonDivisorByEuclidsAlgorithm(width, height);
		
		Self
		{
			width: width / greatestCommonDivisor,
			height: height / greatestCommonDivisor,
		}
	}
	
	#[inline(always)]
	pub fn width(&self) -> u32
	{
		self.width
	}
	
	#[inline(always)]
	pub fn height(&self) -> u32
	{
		self.height
	}
	
	#[inline(always)]
	pub fn to_scalar(&self) -> f64
	{
		(self.width as f64) / (self.height as f64)
	}
}