Added some comments.

src/main.rs

@@ -28,17 +28,20 @@ fn main() {
     opts.optopt("S", "seed", "Rainbow seed, 0 = random", "<i>");
     opts.optflag("h", "help", "Show this message");
 
+    // @todo do not panic!
     let matches = match opts.parse(&args[1..]) {
         Ok(m) => { m }
         Err(f) => { panic!(f.to_string()) }
     };
 
+    // print usage?
     if matches.opt_present("h") {
         print_usage(&program, opts);
 
         return;
     }
 
+    // get spread.
     // @todo this is nasty... fix this.
     let spread : f32 = match matches.opt_default("spread", "3.0") {
         Some(s) => {
@@ -51,6 +54,7 @@ fn main() {
         None => 3.0
     };
 
+    // get freq.
     // @todo this is nasty... fix this.
     let freq : f32 = match matches.opt_default("freq", "0.1") {
         Some(s) => {
@@ -63,6 +67,7 @@ fn main() {
         None => 0.1
     };
 
+    // get seed.
     // @todo this is nasty... fix this.
     let mut seed : i32 = match matches.opt_default("seed", "0") {
         Some(s) => {
@@ -77,6 +82,7 @@ fn main() {
 
     let stdin = io::stdin();
 
+    // @todo I want to use chars() instead, but it's unstable right now :(
     for line in stdin.lock().lines() {
         seed += 1;