Crate cssparser

Implementation of CSS Syntax Module Level 3 for Rust.

Input

Everything is based on Parser objects, which borrow a &str input. If you have bytes (from a file, the network, or something), see the decode_stylesheet_bytes function.

Conventions for parsing functions

• Take (at least) a input: &mut cssparser::Parser parameter
• Return Result<_, ()>
• When returning Ok(_), the function must have consume exactly the amount of input that represents the parsed value.
• When returning Err(()), any amount of input may have been consumed.

As a consequence, when calling another parsing function, either:

• Any Err(()) return value must be propagated. This happens by definition for tail calls, and can otherwise be done with the try! macro.
• Or the call must be wrapped in a Parser::try call. try takes a closure that takes a Parser and returns a Result, calls it once, and returns itself that same result. If the result is Err, it restores the position inside the input to the one saved before calling the closure.

Examples:

// 'none' | <image>
fn parse_background_image(context: &ParserContext, input: &mut Parser)
                                    -> Result<Option<Image>, ()> {
    if input.try(|input| input.expect_ident_matching("none")).is_ok() {
        Ok(None)
    } else {
        Image::parse(context, input).map(Some)  // tail call
    }
}

// [ <length> | <percentage> ] [ <length> | <percentage> ]?
fn parse_border_spacing(_context: &ParserContext, input: &mut Parser)
                          -> Result<(LengthOrPercentage, LengthOrPercentage), ()> {
    let first = try!(LengthOrPercentage::parse);
    let second = input.try(LengthOrPercentage::parse).unwrap_or(first);
    (first, second)
}

Modules

Delimiter

Delimiters constants.

Macros

match_ignore_ascii_case!

This macro is equivalent to a match expression on an &str value, but matching is case-insensitive in the ASCII range.

Structs

CssStringWriter	A fmt::Write adapter that escapes text for writing as a double-quoted CSS string. Quotes are not included.
DeclarationListParser	Provides an iterator for declaration list parsing.
Delimiters	A set of characters, to be used with the Parser::parse_until* methods.
NumericValue	The numeric value of Number and Dimension tokens.
Parser	A CSS parser that borrows its &str input, yields Tokens, and keeps track of nested blocks and functions.
PercentageValue	The numeric value of Percentage tokens.
RGBA	A color with red, green, blue, and alpha components.
RuleListParser	Provides an iterator for rule list parsing.
SourceLocation	The line and column number for a given position within the input.
SourcePosition	A capture of the internal state of a Parser (including the position within the input), obtained from the Parser::position method.
TokenSerializationType	A category of token. See the needs_separator_when_before method.

Enums

AtRuleType	The return value for AtRuleParser::parse_prelude. Indicates whether the at-rule is expected to have a { /* ... */ } block or end with a ; semicolon.
Color	A value.
Token	One of the pieces the CSS input is broken into.

Traits

AtRuleParser	A trait to provide various parsing of at-rules.
DeclarationParser	A trait to provide various parsing of declaration values.
QualifiedRuleParser	A trait to provide various parsing of qualified rules.
ToCss	Trait for things the can serialize themselves in CSS syntax.

Functions

decode_stylesheet_bytes	Determine the character encoding of a CSS stylesheet and decode it.
parse_color_keyword	Return the named color with the given name.
parse_important	Parse !important.
parse_nth	Parse the An+B notation, as found in the :nth-child() selector. The input is typically the arguments of a function, in which case the caller needs to check if the arguments’ parser is exhausted. Return Ok((A, B)), or Err(()) for a syntax error.
parse_one_declaration	Parse a single declaration, such as an ( /* ... */ ) parenthesis in an @supports prelude.
parse_one_rule	Parse a single rule, such as for CSSOM’s CSSStyleSheet.insertRule.
serialize_identifier	Write a CSS identifier, escaping characters as necessary.
serialize_string	Write a double-quoted CSS string token, escaping content as necessary.