css 0.0.22

// 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.


/// A @font-feature-values block declaration value that keeps one or two values.
#[derive(Clone, Debug, PartialEq)]
pub struct PairValues(pub u32, pub Option<u32>);

impl Parse for PairValues
{
	fn parse<'i, 't>(_context: &ParserContext, input: &mut Parser<'i, 't>) -> Result<PairValues, ParseError<'i, CustomParseError<'i>>>
	{
		let first = match *input.next()?
		{
			Token::Number { int_value: Some(firstValue), .. } if firstValue >= 0 => firstValue as u32,
			ref unexpectedToken => return CustomParseError::unexpectedToken(unexpectedToken),
		};

		match input.next()
		{
			Ok(&Token::Number { int_value: Some(secondValue), .. }) if secondValue >= 0 =>
			{
				Ok(PairValues(first, Some(secondValue as u32)))
			}

			// It can't be anything other than number.
			Ok(unexpectedToken) => CustomParseError::unexpectedToken(unexpectedToken),

			// It can be just one value.
			Err(_) => Ok(PairValues(first, None))
		}
	}
}

impl ToCss for PairValues
{
	fn to_css<W: fmt::Write>(&self, dest: &mut W) -> fmt::Result
	{
		self.0.to_css(dest)?;

		if let Some(second) = self.1
		{
			dest.write_char(' ')?;
			second.to_css(dest)?;
		}
		Ok(())
	}
}