use std::borrow::Cow;
use crate::node::element::tag::{Tag, Type};
use crate::node::Attributes;
mod error;
mod reader;
pub use self::error::Error;
#[doc(hidden)]
pub use self::reader::Reader;
pub struct Parser<'l> {
#[allow(dead_code)]
content: Cow<'l, str>,
reader: Reader<'l>,
}
pub enum Event<'l> {
Error(Error),
Tag(&'l str, Type, Attributes),
Text(&'l str),
Comment,
Declaration,
Instruction,
}
pub type Result<T> = ::std::result::Result<T, Error>;
impl<'l> Parser<'l> {
#[inline]
pub fn new<T>(content: T) -> Self
where
T: Into<Cow<'l, str>>,
{
let content = content.into();
let reader = unsafe { ::std::mem::transmute(Reader::new(&*content)) };
Parser { content, reader }
}
}
macro_rules! raise(
($parser:expr, $($argument:tt)*) => (
return Some(Event::Error(Error::new($parser.reader.position(), format!($($argument)*))));
);
);
impl<'l> Iterator for Parser<'l> {
type Item = Event<'l>;
fn next(&mut self) -> Option<Self::Item> {
let content = self.reader.capture(|reader| reader.consume_until_char('<'));
if let Some(content) = content {
return Some(Event::Text(content));
}
if !self.reader.consume_char('<') {
return None;
}
let content = self.reader.capture(|reader| reader.consume_until_char('>'));
if content.is_none() {
raise!(self, "found an empty tag");
}
if !self.reader.consume_char('>') {
raise!(self, "missing a closing angle bracket");
}
let content = content.unwrap();
Some(if content.starts_with("!--") {
Event::Comment
} else if content.starts_with('!') {
Event::Declaration
} else if content.starts_with('?') {
Event::Instruction
} else {
match Tag::parse(&content) {
Ok(Tag(name, kind, attributes)) => Event::Tag(name, kind, attributes),
Err(error) => Event::Error(error),
}
})
}
}
#[cfg(test)]
mod tests {
use crate::parser::{Event, Parser};
#[test]
fn next_tag() {
macro_rules! test(
($content:expr, $value:expr) => ({
let mut parser = Parser::new($content);
match parser.next().unwrap() {
Event::Tag(value, _, _) => assert_eq!(value, $value),
_ => unreachable!(),
}
})
);
test!("<foo>", "foo");
test!("<foo/>", "foo");
test!(" <foo/>", "foo");
}
#[test]
fn next_text() {
macro_rules! test(
($content:expr, $value:expr) => ({
let mut parser = Parser::new($content);
match parser.next().unwrap() {
Event::Text(value) => assert_eq!(value, $value),
_ => unreachable!(),
}
})
);
test!("foo <bar>", "foo");
test!(" foo<bar>", "foo");
test!("foo> <bar>", "foo>");
}
}