[breaking] Implement Iterator for owned ParserIterator (#1587)

* Implement Iterator for owned ParserIterator

Also test and fix doctests and examples

---------

Co-authored-by: ambiso <ambiso@invalid>
Co-authored-by: Geoffroy Couprie <contact@geoffroycouprie.com>

examples/iterator.rs

@@ -71,6 +71,7 @@ fn main() {
   );
 
   let res = nom_it
+    .by_ref()
     .map(|(k, v)| (k.to_uppercase(), v))
     .collect::<HashMap<_, _>>();
 

src/combinator/mod.rs

@@ -881,7 +881,7 @@ where
 /// let data = "abc|defg|hijkl|mnopqr|123";
 /// let mut it = iterator(data, terminated(alpha1, tag("|")));
 ///
-/// let parsed = it.map(|v| (v, v.len())).collect::<HashMap<_,_>>();
+/// let parsed = it.by_ref().map(|v| (v, v.len())).collect::<HashMap<_,_>>();
 /// let res: IResult<_,_> = it.finish();
 ///
 /// assert_eq!(parsed, [("abc", 3usize), ("defg", 4), ("hijkl", 5), ("mnopqr", 6)].iter().cloned().collect());
@@ -917,7 +917,7 @@ impl<I: Clone, E, F> ParserIterator<I, E, F> {
   }
 }
 
-impl<'a, Input, Output, Error, F> core::iter::Iterator for &'a mut ParserIterator<Input, Error, F>
+impl<Input, Output, Error, F> core::iter::Iterator for ParserIterator<Input, Error, F>
 where
   F: Parser<Input, Output = Output, Error = Error>,
   Input: Clone,

tests/issues.rs

@@ -271,3 +271,22 @@ fn issue_1617_count_parser_returning_zero_size() {
     .expect("parsing should succeed");
   assert_eq!(result, ("def", vec![(), (), ()]));
 }
+
+#[test]
+fn issue_1586_parser_iterator_impl() {
+  use nom::{
+    character::complete::{digit1, newline},
+    combinator::{iterator, opt},
+    sequence::terminated,
+    IResult,
+  };
+  fn parse_line(i: &str) -> IResult<&str, &str> {
+    terminated(digit1, opt(newline)).parse(i)
+  }
+
+  fn parse_input(i: &str) -> impl Iterator<Item = i32> + '_ {
+    iterator(i, parse_line).map(|x| x.parse::<i32>().unwrap())
+  }
+
+  assert_eq!(parse_input("123\n456").collect::<Vec<_>>(), vec![123, 456]);
+}