break!: emit chars instead of strings

The HTML spec specifies that the tokenizer emits character tokens.
That html5gum always emitted strings instead was probably just done
to make the token consumption more convenient. When it comes to tree
construction character tokens are however actually more convenient
than string tokens since the spec defines that specific character
tokens should be ignored in specific states (and character tokens
let us avoid string manipulation for these conditions).

This should also make the DefaultEmitter more performant for cases
where you don't actually need the strings at all (or only a few)
since it avoids string allocations. Though I haven't benchmarked it.

1 files changed, 4 insertions, 2 deletions

diff --git a/src/token.rs b/src/token.rs
index c599cd5..cb584ff 100644
--- a/src/token.rs
+++ b/src/token.rs
@@ -9,12 +9,14 @@ use crate::offset::Offset;
 /// A type for the tokens emitted by a WHATWG-compliant HTML tokenizer.
 #[derive(Debug, Eq, PartialEq)]
 pub enum Token<O> {
+    /// A literal character, a resolved character reference,
+    /// or part of a resolved character reference (since some
+    /// character references resolve to two `char`s).
+    Char(char),
     /// An HTML start tag.
     StartTag(StartTag<O>),
     /// An HTML end tag.
     EndTag(EndTag<O>),
-    /// A literal string. Character references have been resolved.
-    String(String),
     /// An HTML comment.
     Comment(Comment<O>),
     /// An HTML doctype declaration.