minify-html/src/unit/tag.rs

80 lines
3.0 KiB
Rust

use crate::err::{HbErr, HbRes};
use crate::proc::Processor;
use crate::spec::codepoint::{is_alphanumeric, is_whitespace};
use crate::spec::tag::void::VOID_TAGS;
use crate::unit::attr::{AttrType, process_attr};
use crate::unit::content::process_content;
use crate::unit::script::process_script;
use crate::unit::style::process_style;
// Tag names may only use ASCII alphanumerics. However, some people also use `:` and `-`.
// See https://html.spec.whatwg.org/multipage/syntax.html#syntax-tag-name for spec.
fn is_valid_tag_name_char(c: u8) -> bool {
is_alphanumeric(c) || c == b':' || c == b'-'
}
pub fn process_tag<'d, 'p>(proc: &'p mut Processor<'d>) -> HbRes<()> {
// Expect to be currently at an opening tag.
cascade_return!(proc.match_char(b'<').expect().keep())
;
// May not be valid tag name at current position, so require instead of expect.
let name_token = cascade_return!(proc.match_while_pred(is_valid_tag_name_char).require_with_reason("tag name")?.keep().range());
let mut last_attr_type = AttrType::None;
let mut self_closing = false;
loop {
// At the beginning of this loop, the last parsed unit was
// either the tag name or an attribute (including its value, if
// it had one).
let ws_accepted = cascade_return!(proc.match_while_pred(is_whitespace).discard().matched());
if cascade_return!(proc.match_char(b'>').keep().matched()) {
// End of tag.
break;
}
self_closing = cascade_return!(proc.match_seq(b"/>").keep().matched());
if self_closing {
break;
}
// HB_ERR_PARSE_NO_SPACE_BEFORE_ATTR is not suppressible as
// otherwise there would be difficulty in determining what is
// the end of a tag/attribute name/attribute value.
if !ws_accepted {
return Err(HbErr::NoSpaceBeforeAttr);
}
if last_attr_type != AttrType::Quoted {
proc.write(b' ');
}
last_attr_type = process_attr(proc)?;
};
if self_closing || VOID_TAGS.contains(&proc[name_token]) {
return Ok(());
};
// TODO WARNING: Tags must be case sensitive.
match &proc[name_token] {
b"script" => process_script(proc)?,
b"style" => process_style(proc)?,
_ => process_content(proc, Some(name_token))?,
_ => unreachable!(),
};
// Require closing tag for non-void.
cascade_return!(proc.match_seq(b"</").require_with_reason("closing tag")?.keep());
let closing_name = cascade_return!(proc.match_while_pred(is_valid_tag_name_char).require_with_reason("closing tag name")?.keep().slice());
if &proc[name_token] != closing_name {
// TODO Find a way to cleanly provide opening and closing tag
// names (which are views) into error message without leaking
// memory.
return Err(HbErr::UnclosedTag);
};
cascade_return!(proc.match_char(b'>').require_with_reason("closing tag")?.keep());
Ok(())
}