diff --git a/src/lib.rs b/src/lib.rs
index 0b4ae41..b5dba51 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,3 @@
 pub mod b64;
-pub mod xor;
 pub mod hex;
+pub mod xor;
diff --git a/src/xor.rs b/src/xor.rs
index 9a81d75..65fc6d9 100644
--- a/src/xor.rs
+++ b/src/xor.rs
@@ -1,49 +1,65 @@
-use hex::{AsHexBytes, HexDigest};
+use std::iter::{Iterator, Map, Zip};
 
-#[derive(Debug)]
-pub enum FixedXORError {
-    Bad,
+//#[derive(Debug)]
+//pub enum FixedXORError {
+//    Bad,
+//}
+
+pub type FixedXOR<T, F> = Map<Zip<T, T>, F>;
+
+pub trait FixedXORable<T, F> {
+    fn fixed_xor(self, other: T) -> FixedXOR<T, F>;
 }
 
-pub fn fixed(a: &str, b: &str) -> Result<String, FixedXORError> {
-    let a_decoded = a.hex_bytes().valid();
-    let b_decoded = b.hex_bytes().valid();
-    let xor: Vec<u8> = a_decoded.zip(b_decoded).map(|(x, y)| x ^ y).collect();
-    Ok(xor.hex_digest())
-}
-
-#[cfg(test)]
-mod tests {
-    use hex::AsHexBytes;
-    use std::char;
-    use super::fixed;
-
-    #[test]
-    fn cryptopals() {
-        let a = "1c0111001f010100061a024b53535009181c";
-        let b = "686974207468652062756c6c277320657965";
-        let ex_output = "746865206b696420646f6e277420706c6179";
-        let output = fixed(a, b);
-        assert_eq!(output.unwrap(), ex_output);
-    }
-
-    static ENGLISH_LETTER_FREQ: &'static str = "EARIOTNSLCUDPMHGBFYWKVXZJQ";
-
-    fn letter_freq_score(input: &str) -> f32 {
-        let mut score: f32 = 0.0;
-        score
-    }
-
-    #[test]
-    fn cryptopals13() {
-        let input = "1b37373331363f78151b7f2b783431333d78397828372d363c78373e783a393b3736";
-        for key in 32u32..127 {
-            let possible_output = input.hex_bytes().valid()
-                .map(|c| char::from_u32(c as u32 ^ key))
-                .take_while(|c| c.is_some())
-                .map(|c| c.unwrap())
-                .collect::<String>();
-            println!("{}: {}", key, possible_output);
-        }
+impl<'a, T, F> FixedXORable<T, F> for T 
+    where T: Iterator<Item=u8> + 'a,
+          F: Fn((u8,u8)) -> u8
+{
+    fn fixed_xor(self, other: T) -> FixedXOR<T, F> {
+        fn xor(tup: (u8, u8)) -> u8 { tup.0 ^ tup.1 }
+        self.zip(other).map(xor)
     }
 }
+
+//pub fn fixed(a: &str, b: &str) -> Result<String, FixedXORError> {
+//    let a_decoded = a.hex_bytes().valid();
+//    let b_decoded = b.hex_bytes().valid();
+//    let xor: Vec<u8> = a_decoded.zip(b_decoded).map(|(x, y)| x ^ y).collect();
+//    Ok(xor.hex_digest())
+//}
+//
+//#[cfg(test)]
+//mod tests {
+//    use hex::AsHexBytes;
+//    use std::char;
+//    use super::fixed;
+//
+//    #[test]
+//    fn cryptopals() {
+//        let a = "1c0111001f010100061a024b53535009181c";
+//        let b = "686974207468652062756c6c277320657965";
+//        let ex_output = "746865206b696420646f6e277420706c6179";
+//        let output = fixed(a, b);
+//        assert_eq!(output.unwrap(), ex_output);
+//    }
+//
+//    static ENGLISH_LETTER_FREQ: &'static str = "EARIOTNSLCUDPMHGBFYWKVXZJQ";
+//
+//    fn letter_freq_score(input: &str) -> f32 {
+//        let mut score: f32 = 0.0;
+//        score
+//    }
+//
+//    #[test]
+//    fn cryptopals13() {
+//        let input = "1b37373331363f78151b7f2b783431333d78397828372d363c78373e783a393b3736";
+//        for key in 32u32..127 {
+//            let possible_output = input.hex_bytes().valid()
+//                .map(|c| char::from_u32(c as u32 ^ key))
+//                .take_while(|c| c.is_some())
+//                .map(|c| c.unwrap())
+//                .collect::<String>();
+//            println!("{}: {}", key, possible_output);
+//        }
+//    }
+//}