Added logger macro

src/util/logger.rs

@@ -1,13 +1,23 @@
-fn l1_log(verbosity: u8, message: &str) {
-    if verbosity > 0 {
-        println!("{}", message);
+// prints output to the stderr if the verbosity is
+// greater than or equal to the logging level of the
+// notification.
+macro_rules! log {
+    // NOTE: this uses a variadic argument system
+    // copied from the std::fmt eprintln! macro
+    // see the appropriate documentation
+    ($l:expr, $v:expr, $($arg:tt)*) => {{
+        if $v >= $l {
+            eprintln!($($arg)*);
         }
+    }};
 }
 
-fn l2_log(verbosity: u8, message: &str) {
-    if verbosity > 1 {
-        println!("{}", message);
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_name() {
+        log!(1, 1, "this is a {}", "test");
     }
 }
-
-//TODO unit test, but these are trivial