rdom-parser

HTML-ish template parser for rdom-core. The parseFromString equivalent for the rdom family.

Hand-rolled recursive descent. Zero runtime dependencies beyond rdom-core.

Quick start

use rdom_parser::parse;
use rdom_core::Dom;

let (dom, ids): (Dom<()>, _) = parse(r#"
    <div class="hero" id="main">
        <h1>Welcome</h1>
        <p>Hello &amp; <strong>world</strong></p>
    </div>
"#).unwrap();

For building into an existing tree:

use rdom_parser::parse_into;

let mut dom: Dom<()> = Dom::new();
let body = dom.create_element("body");
dom.append_child(dom.root(), body).unwrap();

let children = parse_into(&mut dom, "<h1>Title</h1><p>Body</p>", body)?;

Supported

Start, end, self-closing tags; case-insensitive tag names (normalized to lowercase)
Void elements (<br>, <hr>, <img>, <input>, …) auto-close
Attributes: name="value", name='value', name=value, name (boolean)
class="a b c" populates the classList
Text with entity decoding: &, <, >, ", ',  , &#NNN;, &#xHH;
Comments:  preserved as Comment nodes
Full UTF-8: CJK, emoji, ZWJ sequences, combining marks all preserved correctly

Not supported

<!DOCTYPE> — skip in your source if you have it
CDATA sections, namespace prefixes, processing instructions
<script> / <style> raw-text mode (our DOM has no corresponding tags)
Mismatched tags — errors, not auto-repaired

Error reporting

ParseError carries line + column + byte offset + optional hint:

use rdom_parser::parse;
use rdom_core::Dom;

let err = parse::<()>("<div><span></p></div>").unwrap_err();
assert!(err.msg.contains("mismatched"));
assert!(err.hint.is_some());
println!("{err}"); // "parse error at line 1, col 14: …"

Round-tripping

For a well-behaved subset, parse(x).outer_markup() == x:

let src = "<div><p>Hello &amp; world</p></div>";
let (dom, ids) = parse::<()>(src).unwrap();
assert_eq!(dom.outer_markup(ids[0]), src);

Caveats: attributes serialize in alphabetic order, classes serialize in alphabetic order, text entities only escape & < > (not " or ' outside attributes).

Examples

cargo run -p rdom-parser --example parse_html
cargo run -p rdom-parser --example round_trip

parse_html walks a parsed tree and runs selector queries; round_trip verifies parse ↔ serialize equivalence on a corpus of well-behaved snippets.

For an end-to-end "parse → cascade → paint to terminal" demo, see rdom-tui's parse_and_render example.

Testing

cargo test -p rdom-parser

92 tests covering parsing, entity decoding, nesting, errors, round-tripping, realistic template snippets, and Unicode content.

rdom-parser 0.3.0