--- a/solutions/cw2/lexer.sc	Tue Sep 19 09:54:41 2023 +0100
+++ b/solutions/cw2/lexer.sc	Tue Sep 19 12:56:10 2023 +0100
@@ -375,3 +375,20 @@
 println(size(ders_simp("r".toList, WHILE_REGS)))
 println(size(ID))
 println(size(ders_simp("read".toList, ID)))
+
+
+
+// for automated testing
+
+@main
+def main(file: String) = {
+  // empty - nothing to run
+}
+
+@main
+def test(file: String) = {
+  val contents = os.read(os.pwd / file)
+  tokenise(contents)
+}
+
+