fix: not generates the wrong location for the error (#824) (#825)

* fix: `not` generates the wrong location for the error (#824)

* fix: use `peek_maybe` instead of `peek_inner`

Author: Hedgehogo

src/combinator.rs

@@ -2352,12 +2352,8 @@ where
 
         match result {
             Ok(()) => {
-                let found = inp.next_inner();
-                inp.add_alt(
-                    [DefaultExpected::SomethingElse],
-                    found.map(|f| f.into()),
-                    result_span,
-                );
+                let found = inp.peek_maybe();
+                inp.add_alt([DefaultExpected::SomethingElse], found, result_span);
                 Err(())
             }
             Err(()) => Ok(M::bind(|| ())),

src/lib.rs

@@ -4001,6 +4001,21 @@ mod tests {
         );
     }
 
+    #[test]
+    fn labelled_not() {
+        use crate::{DefaultExpected, LabelError};
+
+        let parser = any::<_, extra::Err<Rich<_>>>().not().labelled("label");
+
+        let mut err = LabelError::<&str, _>::expected_found(
+            [DefaultExpected::SomethingElse],
+            Some('b'.into()),
+            SimpleSpan::new((), 0..1),
+        );
+        LabelError::<&str, _>::label_with(&mut err, "label");
+        assert_eq!(parser.parse("b").into_output_errors(), (None, vec![err]));
+    }
+
     #[test]
     fn state_rewind() {
         use crate::{extra::Full, inspector::TruncateState};