MMM: Fixed hashtag parsing

magnetar_mmm_parser/src/lib.rs

@@ -7,7 +7,7 @@ use nom::character::complete::{
     satisfy, space1, tab,
 };
 use nom::combinator::{eof, fail, map, not, opt, recognize};
-use nom::error::{ErrorKind, ParseError};
+use nom::error::ErrorKind;
 use nom::multi::{many0, many0_count, many1, many1_count, many_till, separated_list1};
 use nom::sequence::tuple;
 use nom::{IResult, Offset, Parser, Slice};
@@ -277,6 +277,14 @@ fn alpha1_unicode(input: Span) -> IResult<Span, Span> {
     recognize(many1_count(satisfy(char::is_alphanumeric)))(input)
 }
 
+#[inline]
+fn space1_unicode(input: Span) -> IResult<Span, Span> {
+    recognize(many1_count(tuple((
+        not(line_ending),
+        satisfy(char::is_whitespace),
+    ))))(input)
+}
+
 #[inline]
 fn alphanumeric1_unicode(input: Span) -> IResult<Span, Span> {
     recognize(many1_count(satisfy(char::is_alphanumeric)))(input)
@@ -1293,7 +1301,12 @@ impl Context {
     }
 
     fn tag_hashtag<'a>(&self, input: Span<'a>) -> IResult<Span<'a>, Token> {
-        // TODO: Skip when preceded by alphanumerics
+        let (input, maybe_preceded) =
+            opt(recognize(tuple((alphanumeric1_unicode, tag("#")))))(input)?;
+
+        if let Some(preceded) = maybe_preceded {
+            return Ok((input, Token::PlainText(preceded.into_fragment().into())));
+        }
 
         let (input, _) = tag("#")(input)?;
 
@@ -1347,8 +1360,8 @@ impl Context {
                 tag("）"),
             ))),
             recognize(tuple((
-                not(space1),
-                not_line_ending,
+                not(space1_unicode),
+                not(line_ending),
                 not(one_of(".,:;!?#?/[]【】()「」（）<>")),
                 anychar,
             ))),
@@ -1699,6 +1712,20 @@ text</center>"#
             ])
         );
 
+        assert_eq!(
+            parse_full("test #hashtag tail"),
+            Token::Sequence(vec![
+                Token::PlainText("test ".into()),
+                Token::Hashtag("hashtag".into()),
+                Token::PlainText(" tail".into())
+            ])
+        );
+
+        assert_eq!(
+            parse_full("not#hashtag tail"),
+            Token::PlainText("not#hashtag tail".into())
+        );
+
         assert_eq!(
             parse_full("<https://example.com>"),
             Token::UrlNoEmbed("https://example.com".into())