break!: remove Token::Error

An error isn't a token (in general and also according to the spec).
You shouldn't have to filter out errors when you're just interested
in tokens but most importantly having errors in the Token enum is
annoying when implementing tree construction (since the spec conditions
exhaustively cover all Token variants except Token::Error).

1 files changed, 10 insertions, 1 deletions

diff --git a/src/default_emitter.rs b/src/default_emitter.rs
index a4c5a63..e89fa5e 100644
--- a/src/default_emitter.rs
+++ b/src/default_emitter.rs
@@ -17,6 +17,7 @@ pub struct DefaultEmitter<O = NoopOffset> {
     current_attribute: Option<(String, crate::token::AttrInternal<O>)>,
     seen_attributes: BTreeSet<String>,
     emitted_tokens: VecDeque<Token<O>>,
+    errors: VecDeque<(Error, Range<O>)>,
     attr_in_end_tag_span: Option<Range<O>>,
 }
 
@@ -28,11 +29,19 @@ impl<O> Default for DefaultEmitter<O> {
             current_attribute: None,
             seen_attributes: BTreeSet::new(),
             emitted_tokens: VecDeque::new(),
+            errors: VecDeque::new(),
             attr_in_end_tag_span: None,
         }
     }
 }
 
+impl<O> DefaultEmitter<O> {
+    /// Removes all encountered tokenizer errors and returns them as an iterator.
+    pub fn drain_errors(&mut self) -> impl Iterator<Item = (Error, Range<O>)> + '_ {
+        self.errors.drain(0..)
+    }
+}
+
 impl<O> Iterator for DefaultEmitter<O> {
     type Item = Token<O>;
 
@@ -43,7 +52,7 @@ impl<O> Iterator for DefaultEmitter<O> {
 
 impl<O: Offset> Emitter<O> for DefaultEmitter<O> {
     fn report_error(&mut self, error: Error, span: Range<O>) {
-        self.emitted_tokens.push_front(Token::Error { error, span });
+        self.errors.push_back((error, span));
     }
 
     fn emit_eof(&mut self) {