1 files changed, 27 insertions, 0 deletions
diff --git a/src/syntax.rs b/src/syntax.rs
new file mode 100644
index 0000000..abf7309
--- /dev/null
+++ b/src/syntax.rs
@@ -0,0 +1,27 @@
+pub mod ast;
+pub mod parse;
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn parse_valid() {
+        assert!(parse::parse("").is_ok());
+        assert!(parse::parse("a").is_ok());
+        assert!(parse::parse("ab").is_ok());
+        assert!(parse::parse("abc").is_ok());
+        assert!(parse::parse("a|b").is_ok());
+        assert!(parse::parse("a|b*").is_ok());
+        assert!(parse::parse("(a|b)*").is_ok());
+        assert!(parse::parse("(((a|b)))*").is_ok());
+        assert!(parse::parse("a*b*").is_ok());
+    }
+
+    #[test]
+    fn parse_invalid() {
+        assert!(parse::parse("(").is_err());
+        assert!(parse::parse("()))").is_err());
+        assert!(parse::parse("(((())").is_err());
+    }
+}