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 struct LanguageRange(Atom);

impl Separated for LanguageRange
{
	type Delimiter = Comma;
}

impl ToCss for LanguageRange
{
	fn to_css<W: fmt::Write>(&self, dest: &mut W) -> fmt::Result
	{
		let value = &(self.0).0;
		
		let isCssIdentifier = if value.is_empty()
		{
			false
		}
		else
		{
			let mut characters = value.chars();
			
			match characters.next().unwrap()
			{
				'a' ... 'z' | 'A' ... 'Z' | '-' =>
				{
					let mut isCssIdentifier = true;
					for character in characters
					{
						match character
						{
							'a' ... 'z' | 'A' ... 'Z' | '-' | '0' ... '9' => continue,
							_ =>
							{
								isCssIdentifier = false;
								break
							}
						}
					}
					isCssIdentifier
				}
				_ => false
			}
		};
		
		if isCssIdentifier
		{
			serialize_identifier(value, dest)
		}
		else
		{
			serialize_string(value, dest)
		}
	}
}

impl LanguageRange
{
	/// Returns whether the language is matched, as defined by [RFC 4647](https://tools.ietf.org/html/rfc4647#section-3.3.2).
	pub fn matches_language(&self, tag: &str) -> bool
	{
		// step 1
		let mut range_subtags = (self.0).0.split('\x2d');
		let mut tag_subtags = tag.split('\x2d');
		
		// step 2
		// Note: [Level-4 spec](https://drafts.csswg.org/selectors/#lang-pseudo) check for wild card
		if let (Some(range_subtag), Some(tag_subtag)) = (range_subtags.next(), tag_subtags.next())
		{
			if !(range_subtag.eq_ignore_ascii_case(tag_subtag) || range_subtag.eq_ignore_ascii_case("*"))
			{
				return false;
			}
		}
		
		let mut current_tag_subtag = tag_subtags.next();
		
		// step 3
		for range_subtag in range_subtags
		{
			// step 3a
			if range_subtag == "*"
			{
				continue;
			}
			
			match current_tag_subtag.clone()
			{
				Some(tag_subtag) =>
				{
					// step 3c
					if range_subtag.eq_ignore_ascii_case(tag_subtag)
					{
						current_tag_subtag = tag_subtags.next();
						continue;
					}
					
					// step 3d
					if tag_subtag.len() == 1
					{
						return false;
					}
					
					// else step 3e - continue with loop
					current_tag_subtag = tag_subtags.next();
					if current_tag_subtag.is_none()
					{
						return false;
					}
				},
				
				// step 3b
				None =>
				{
					return false;
				}
			}
		}
		
		// step 4
		true
	}
}