Allow many ':' in attributes

To do this, "try_namespace_name" now looks for nested namespaces.
Because 'try_name' gets called, another Ident must be consumed to
prevent and early return, which means that "::" would not be valid,
but "a:b-c:d" would be fine.

maud/tests/basic_syntax.rs

@@ -181,6 +181,16 @@ fn hyphens_in_attribute_names() {
     );
 }
 
+#[test]
+fn many_colons_in_names() {
+    let result =
+        html! { namespace:other-namespace:this is:some:sentence="false" of:course:it:is {} };
+    assert_eq!(
+        result.into_string(),
+        r#"<namespace:other-namespace:this is:some:sentence="false" of:course:it:is></namespace:other-namespace:this>"#
+    );
+}
+
 #[test]
 fn class_shorthand() {
     let result = html! { p { "Hi, " span.name { "Lyra" } "!" } };

maud_macros/src/parse.rs

@@ -731,11 +731,13 @@ impl Parser {
     /// if necessary.
     fn try_namespaced_name(&mut self) -> Option<TokenStream> {
         let mut result = vec![self.try_name()?];
-        if let Some(TokenTree::Punct(ref punct)) = self.peek() {
+        while let Some(TokenTree::Punct(ref punct)) = self.peek() {
             if punct.as_char() == ':' {
                 self.advance();
                 result.push(TokenStream::from(TokenTree::Punct(punct.clone())));
                 result.push(self.try_name()?);
+            } else {
+                break;
             }
         }
         Some(result.into_iter().collect())