Add skip_next_empty field for FindCaptures and FindMatches

Author: defuz

regex_macros/tests/tests.rs

@@ -45,6 +45,27 @@ fn empty_regex_nonempty_match() {
     assert_eq!(ms, vec![(0, 0), (1, 1), (2, 2), (3, 3)]);
 }
 
+#[test]
+fn one_zero_length_match() {
+    let re = regex!(r"\d*");
+    let ms = re.find_iter("a1b2").collect::<Vec<_>>();
+    assert_eq!(ms, vec![(0, 0), (1, 2), (3, 4)]);
+}
+
+#[test]
+fn many_zero_length_match() {
+    let re = regex!(r"\d*");
+    let ms = re.find_iter("a1bbb2").collect::<Vec<_>>();
+    assert_eq!(ms, vec![(0, 0), (1, 2), (3, 3), (4, 4), (5, 6)]);
+}
+
+#[test]
+fn many_sequential_zero_length_match() {
+    let re = regex!(r"\d?");
+    let ms = re.find_iter("a12b3c").collect::<Vec<_>>();
+    assert_eq!(ms, vec![(0, 0), (1, 2), (2, 3), (4, 5), (6, 6)]);
+}
+
 #[test]
 fn quoted_bracket_set() {
     let re = regex!(r"([\x{5b}\x{5d}])");

src/re.rs

@@ -350,6 +350,7 @@ impl Regex {
             re: self,
             search: text,
             last_end: 0,
+            skip_next_empty: false
         }
     }
 
@@ -454,6 +455,7 @@ impl Regex {
             re: self,
             search: text,
             last_end: 0,
+            skip_next_empty: false
         }
     }
 
@@ -1058,6 +1060,7 @@ pub struct FindCaptures<'r, 't> {
     re: &'r Regex,
     search: &'t str,
     last_end: usize,
+    skip_next_empty: bool
 }
 
 impl<'r, 't> Iterator for FindCaptures<'r, 't> {
@@ -1079,8 +1082,13 @@ impl<'r, 't> Iterator for FindCaptures<'r, 't> {
         if e == s {
             self.last_end += self.search[self.last_end..].chars()
                                  .next().map(|c| c.len_utf8()).unwrap_or(1);
+            if self.skip_next_empty {
+                self.skip_next_empty = false;
+                return self.next();
+            }
         } else {
             self.last_end = e;
+            self.skip_next_empty = true;
         }
         Some(Captures::new(self.re, self.search, caps))
     }
@@ -1098,6 +1106,7 @@ pub struct FindMatches<'r, 't> {
     re: &'r Regex,
     search: &'t str,
     last_end: usize,
+    skip_next_empty: bool
 }
 
 impl<'r, 't> Iterator for FindMatches<'r, 't> {
@@ -1119,8 +1128,13 @@ impl<'r, 't> Iterator for FindMatches<'r, 't> {
         if e == s {
             self.last_end += self.search[self.last_end..].chars()
                                  .next().map(|c| c.len_utf8()).unwrap_or(1);
+            if self.skip_next_empty {
+                self.skip_next_empty = false;
+                return self.next();
+            }
         } else {
             self.last_end = e;
+            self.skip_next_empty = true;
         }
         Some((s, e))
     }