Implement Display for Numbers

types/src/number/mod.rs

@@ -6,8 +6,10 @@
 ///
 /// Scheme numbers are complex, literally.
 
+use std::fmt;
+
 pub mod real;
-//mod add;
+mod add;
 mod math;
 
 pub use self::real::Real;
@@ -62,6 +64,15 @@ impl Number {
     pub fn is_exact(&self) -> bool { self.exact }
 }
 
+impl fmt::Display for Number {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.real).and_then(|r| match self.imag {
+            Some(ref imag) => write!(f, "{}i", imag),
+            None => Ok(r),
+        })
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::Number;