--- a/src/lib.rs	Thu Jul 18 17:31:14 2019 +0200
+++ b/src/lib.rs	Thu Jul 18 17:40:44 2019 +0200
@@ -7,6 +7,8 @@
 mod repr;
 mod state;
 
+mod tests;
+
 /// Compiles a parsed regular expression into the internal state graph and matches s against it.
 /// Returns whether the string matched as well as a list of submatches. The first submatch is the
 /// entire matched string. A submatch is a tuple of (start, end), where end is the index of the

--- a/src/matching.rs	Thu Jul 18 17:31:14 2019 +0200
+++ b/src/matching.rs	Thu Jul 18 17:40:44 2019 +0200
@@ -65,6 +65,9 @@
 /// do_match starts the matching process. It tries to match the supplied compiled regex against the
 /// supplied string. If it fails, it skips ahead and tries later in the string (i.e., if the regex
 /// isn't anchored, it will do a full-text match).
+///
+/// The boolean component is true if the match succeeded. The Vec contains tuples of (start,
+/// one-past-end) for each submatch, starting with the implicit whole match.
 pub fn do_match(ws: WrappedState, s: &str) -> (bool, Vec<(usize, usize)>) {
     let mut ms = MatchState::new(s, ws);
     let (mut i, len) = (0, s.len());

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/tests.rs	Thu Jul 18 17:40:44 2019 +0200
@@ -0,0 +1,22 @@
+#![cfg(test)]
+
+//! A general test suite aiming for wide coverage of positive and negative matches.
+
+use crate::{compile, matching, parse};
+
+fn match_re(re: &str, s: &str) -> (bool, Vec<(usize, usize)>) {
+    let parsed = parse::parse(re).unwrap();
+    let ready = compile::start_compile(&parsed);
+    matching::do_match(ready, s)
+}
+
+#[test]
+fn test_simple_repeat() {
+    assert!(match_re("a+", "aaa").0);
+    assert!(match_re("aaa+", "aaa").0);
+    assert!(match_re("aa(a+)", "aaa").0);
+    assert_eq!(vec![(0, 3), (2, 3)], match_re("aa(a+)", "aaa").1);
+    assert_eq!(vec![(0, 3)], match_re("aaa+", "aaabcde").1);
+    assert!(!match_re("a+", "").0);
+    assert!(!match_re("aa+$", "aaabc").0);
+}