impl SeparatedByWithTrailing combinator

1 files changed, 74 insertions, 0 deletions

diff --git a/src/lib.rs b/src/lib.rs
index 7c1bbcc..02972af 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -169,6 +169,16 @@ pub trait Parser<I: Input>: Sized {
         }
     }
 
+    fn separated_by_with_trailing<P>(self, delimiter: P) -> impl ParserIter<I, Item = Self::Output>
+    where
+        P: Parser<I>,
+    {
+        SeparatedByWithTrailing {
+            parser: self,
+            delimiter,
+        }
+    }
+
     fn find(self) -> impl ParserIter<I, Item = Self::Output> {
         Find { parser: self }
     }
@@ -274,6 +284,44 @@ where
     }
 }
 
+struct SeparatedByWithTrailing<P1, P2> {
+    parser: P1,
+    delimiter: P2,
+}
+
+impl<I, P1, P2> ParserIter<I> for SeparatedByWithTrailing<P1, P2>
+where
+    I: Input,
+    P1: Parser<I>,
+    P2: Parser<I>,
+{
+    type Item = P1::Output;
+
+    fn next<OM: Mode, EM: Mode>(
+        &self,
+        it: InputIter<I>,
+    ) -> Option<ParserResult<I, Self::Item, OM, EM>> {
+        if it.is_finished() {
+            None
+        } else {
+            let (rest, output) = match self.parser.run::<OM, EM>(it) {
+                Ok((rest, output)) => match self.delimiter.check(rest.clone()) {
+                    Ok(_) => (rest, output),
+                    Err(_) => return Some(Err(EM::bind(|| rest))),
+                },
+                Err(rest) => return Some(Err(rest)),
+            };
+
+            let rest = match self.delimiter.check(rest.clone()) {
+                Ok((rest, _)) => rest,
+                _ => rest,
+            };
+
+            Some(Ok((rest, output)))
+        }
+    }
+}
+
 struct AtLeast<P> {
     parser: P,
     count: usize,
@@ -1047,6 +1095,32 @@ mod test {
     }
 
     #[test]
+    fn test_separated_by_with_trailing() {
+        let input = "1.0.";
+        let it = InputIter::new(input);
+
+        numeric1()
+            .separated_by_with_trailing(tag("."))
+            .at_least(1)
+            .check_finished(it)
+            .unwrap();
+    }
+
+    #[test]
+    fn test_separated_by_with_trailing_without_trailing() {
+        let input = "1.0";
+        let it = InputIter::new(input);
+
+        assert!(
+            numeric1()
+                .separated_by_with_trailing(tag("."))
+                .at_least(1)
+                .check_finished(it)
+                .is_err()
+        );
+    }
+
+    #[test]
     fn test_find() {
         let input = "hello world";
         let it = InputIter::new(input);