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#![doc(html_root_url = "https://docs.rs/simplecss/0.2.1")]
#![forbid(unsafe_code)]
#![warn(missing_docs)]
use std::fmt;
use log::warn;
mod selector;
mod stream;
pub use selector::*;
use stream::Stream;
#[derive(Clone, Copy, PartialEq, Debug)]
pub enum Error {
UnexpectedEndOfStream,
InvalidIdent(TextPos),
InvalidComment(TextPos),
InvalidValue(TextPos),
#[allow(missing_docs)]
InvalidByte { expected: u8, actual: u8, pos: TextPos },
SelectorMissing,
UnexpectedSelector,
UnexpectedCombinator,
InvalidAttributeSelector,
InvalidLanguagePseudoClass,
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match *self {
Error::UnexpectedEndOfStream => {
write!(f, "unexpected end of stream")
}
Error::InvalidIdent(pos) => {
write!(f, "invalid ident at {}", pos)
}
Error::InvalidComment(pos) => {
write!(f, "invalid comment at {}", pos)
}
Error::InvalidValue(pos) => {
write!(f, "invalid value at {}", pos)
}
Error::InvalidByte { expected, actual, pos } => {
write!(f, "expected '{}' not '{}' at {}",
expected as char, actual as char, pos)
}
Error::SelectorMissing => {
write!(f, "selector missing")
}
Error::UnexpectedSelector => {
write!(f, "unexpected selector")
}
Error::UnexpectedCombinator => {
write!(f, "unexpected combinator")
}
Error::InvalidAttributeSelector => {
write!(f, "invalid or unsupported attribute selector")
}
Error::InvalidLanguagePseudoClass => {
write!(f, "invalid language pseudo-class")
}
}
}
}
impl std::error::Error for Error {}
#[derive(Clone, Copy, PartialEq, Debug)]
#[allow(missing_docs)]
pub struct TextPos {
pub row: u32,
pub col: u32,
}
impl TextPos {
pub fn new(row: u32, col: u32) -> TextPos {
TextPos { row, col }
}
}
impl fmt::Display for TextPos {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
write!(f, "{}:{}", self.row, self.col)
}
}
#[derive(Clone, Copy, PartialEq, Debug)]
#[allow(missing_docs)]
pub struct Declaration<'a> {
pub name: &'a str,
pub value: &'a str,
pub important: bool,
}
#[derive(Clone, Debug)]
pub struct Rule<'a> {
pub selector: Selector<'a>,
pub declarations: Vec<Declaration<'a>>,
}
#[derive(Clone, Debug)]
pub struct StyleSheet<'a> {
pub rules: Vec<Rule<'a>>,
}
impl<'a> StyleSheet<'a> {
pub fn new() -> Self {
StyleSheet { rules: Vec::new() }
}
pub fn parse(text: &'a str) -> Self {
let mut sheet = StyleSheet::new();
sheet.parse_more(text);
sheet
}
pub fn parse_more(&mut self, text: &'a str) {
let mut s = Stream::from(text);
if s.skip_spaces_and_comments().is_err() {
return;
}
while !s.at_end() {
if s.skip_spaces_and_comments().is_err() {
break;
}
let _ = consume_statement(&mut s, &mut self.rules);
}
if !s.at_end() {
warn!("{} bytes were left.", s.slice_tail().len());
}
self.rules.retain(|rule| !rule.declarations.is_empty());
self.rules.sort_by_cached_key(|rule| rule.selector.specificity());
}
}
impl fmt::Display for StyleSheet<'_> {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
for (i, rule) in self.rules.iter().enumerate() {
write!(f, "{} {{ ", rule.selector)?;
for dec in &rule.declarations {
write!(f, "{}:{}", dec.name, dec.value)?;
if dec.important {
write!(f, " !important")?;
}
write!(f, ";")?;
}
write!(f, " }}")?;
if i != self.rules.len() - 1 {
writeln!(f)?;
}
}
Ok(())
}
}
fn consume_statement<'a>(s: &mut Stream<'a>, rules: &mut Vec<Rule<'a>>) -> Result<(), Error> {
if s.curr_byte() == Ok(b'@') {
s.advance(1);
consume_at_rule(s)
} else {
consume_rule_set(s, rules)
}
}
fn consume_at_rule(s: &mut Stream) -> Result<(), Error> {
let ident = s.consume_ident()?;
warn!("The @{} rule is not supported. Skipped.", ident);
s.skip_bytes(|c| c != b';' && c != b'{');
match s.curr_byte()? {
b';' => s.advance(1),
b'{' => consume_block(s),
_ => {}
}
Ok(())
}
fn consume_rule_set<'a>(s: &mut Stream<'a>, rules: &mut Vec<Rule<'a>>) -> Result<(), Error> {
let start_rule_idx = rules.len();
while s.curr_byte()? == b',' || start_rule_idx == rules.len() {
if s.curr_byte()? == b',' {
s.advance(1);
}
let (selector, offset) = crate::selector::parse(s.slice_tail());
s.advance(offset);
s.skip_spaces();
if let Some(selector) = selector {
rules.push(Rule { selector, declarations: Vec::new() });
}
match s.curr_byte()? {
b'{' => break,
b',' => {}
_ => {
s.skip_bytes(|c| c != b'{');
break;
}
}
}
s.try_consume_byte(b'{');
let declarations = consume_declarations(s)?;
for i in start_rule_idx..rules.len() {
rules[i].declarations = declarations.clone();
}
s.try_consume_byte(b'}');
Ok(())
}
fn consume_block(s: &mut Stream) {
s.try_consume_byte(b'{');
consume_until_block_end(s);
}
fn consume_until_block_end(s: &mut Stream) {
let mut braces = 0;
while !s.at_end() {
match s.curr_byte_unchecked() {
b'{' => {
braces += 1;
}
b'}' => {
if braces == 0 {
break;
} else {
braces -= 1;
}
}
_ => {}
}
s.advance(1);
}
s.try_consume_byte(b'}');
}
fn consume_declarations<'a>(s: &mut Stream<'a>) -> Result<Vec<Declaration<'a>>, Error> {
let mut declarations = Vec::new();
while !s.at_end() && s.curr_byte() != Ok(b'}') {
match consume_declaration(s) {
Ok(declaration) => declarations.push(declaration),
Err(_) => {
consume_until_block_end(s);
break;
}
}
}
Ok(declarations)
}
pub struct DeclarationTokenizer<'a> {
stream: Stream<'a>,
}
impl<'a> From<&'a str> for DeclarationTokenizer<'a> {
fn from(text: &'a str) -> Self {
DeclarationTokenizer {
stream: Stream::from(text),
}
}
}
impl<'a> Iterator for DeclarationTokenizer<'a> {
type Item = Declaration<'a>;
fn next(&mut self) -> Option<Self::Item> {
let _ = self.stream.skip_spaces_and_comments();
if self.stream.at_end() {
return None;
}
match consume_declaration(&mut self.stream) {
Ok(v) => Some(v),
Err(_) => {
self.stream.jump_to_end();
None
}
}
}
}
fn consume_declaration<'a>(s: &mut Stream<'a>) -> Result<Declaration<'a>, Error> {
s.skip_spaces_and_comments()?;
if s.curr_byte() == Ok(b'*') {
s.advance(1);
}
let name = s.consume_ident()?;
s.skip_spaces_and_comments()?;
s.consume_byte(b':')?;
s.skip_spaces_and_comments()?;
let start = s.pos();
let mut end = s.pos();
while consume_term(s).is_ok() {
end = s.pos();
s.skip_spaces_and_comments()?;
}
let value = s.slice_range(start, end).trim();
s.skip_spaces_and_comments()?;
let mut important = false;
if s.curr_byte() == Ok(b'!') {
s.advance(1);
s.skip_spaces_and_comments()?;
if s.slice_tail().starts_with("important") {
s.advance(9);
important = true;
}
}
s.skip_spaces_and_comments()?;
while s.curr_byte() == Ok(b';') {
s.advance(1);
s.skip_spaces_and_comments()?;
}
s.skip_spaces_and_comments()?;
if value.is_empty() {
return Err(Error::InvalidValue(s.gen_text_pos_from(start)));
}
Ok(Declaration { name, value, important })
}
fn consume_term(s: &mut Stream) -> Result<(), Error> {
fn consume_digits(s: &mut Stream) {
while let Ok(c) = s.curr_byte() {
match c {
b'0'..=b'9' => s.advance(1),
_ => break,
}
}
}
match s.curr_byte()? {
b'#' => {
s.advance(1);
match s.consume_ident() {
Ok(_) => {}
Err(_) => {
while let Ok(c) = s.curr_byte() {
match c {
b'0'..=b'9' | b'a'..=b'f' | b'A'..=b'F' => s.advance(1),
_ => break,
}
}
}
}
}
b'+' | b'-' | b'0'..=b'9' | b'.' => {
s.advance(1);
consume_digits(s);
if s.curr_byte() == Ok(b'.') {
s.advance(1);
consume_digits(s);
}
if s.curr_byte() == Ok(b'%') {
s.advance(1);
} else {
let _ = s.consume_ident();
}
}
b'\'' | b'"' => {
s.consume_string()?;
}
b',' => {
s.advance(1);
}
_ => {
let _ = s.consume_ident()?;
if s.curr_byte() == Ok(b'(') {
s.skip_bytes(|c| c != b')');
s.consume_byte(b')')?;
}
}
}
Ok(())
}