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, Clone, Ord, PartialOrd, Eq, PartialEq, Hash)]
pub enum CalculablePropertyValue<U: Unit>
{
	Constant(U),
	
	Percentage(PercentageUnit<U::Number>),
	
	Calc(CalcFunction<U>),
	
	Attr(AttrFunction),
	
	Var(VarFunction),
}

impl<U: Unit> Default for CalculablePropertyValue<U>
{
	#[inline(always)]
	fn default() -> Self
	{
		CalculablePropertyValue::Constant(U::default())
	}
}

impl<U: Unit> ToCss for CalculablePropertyValue<U>
{
	fn to_css<W: fmt::Write>(&self, dest: &mut W) -> fmt::Result
	{
		use self::CalculablePropertyValue::*;
		
		match *self
		{
			Constant(ref constant) => constant.to_css(dest),
			
			Percentage(ref percentage) => percentage.to_css(dest),
			
			Calc(ref function) => function.to_css(dest),
			
			Attr(ref function) => function.to_css(dest),
			
			Var(ref function) => function.to_css(dest),
		}
	}
}

impl<U: Unit> Expression<U> for CalculablePropertyValue<U>
{
	/// Evaluate the CalculablePropertyValue by returning the numeric value of the canonical dimension
	/// Division by zero is handled by returning the maximum possible f32 value
	/// Subtractions for UnsignedCssNumber that are negative are handled by returning 0.0
	#[inline(always)]
	fn evaluate<Conversion: FontRelativeLengthConversion<U::Number> + ViewportPercentageLengthConversion<U::Number> + PercentageConversion<U::Number> + AttributeConversion<U> + CssVariableConversion>(&self, conversion: &Conversion) -> Option<U::Number>
	{
		use self::CalculablePropertyValue::*;
		
		match *self
		{
			Constant(ref constant) => Some(constant.to_CssNumber()),
			
			Percentage(ref percentage) => Some(percentage.to_absolute_value(conversion)),
			
			Calc(ref function) => function.evaluate(conversion),
			
			Attr(ref function) => function.evaluate(conversion),
			
			Var(ref function) => function.evaluate(conversion),
		}
	}
}