Merge branch 'port-numbers'

types/src/number/integer.rs

@@ -3,13 +3,22 @@
  */
 
 use std::any::Any;
+use std::fmt;
 use number::Number;
 use object::{Obj, Object};
 
-pub type Int = i64;
+#[derive(Debug, Eq, PartialEq)]
+pub struct Int(i64);
+
+impl fmt::Display for Int {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
 
 impl Object for Int {
     fn as_any(&self) -> &Any { self }
+    fn as_num(&self) -> Option<&Number> { Some(self) }
 }
 
 impl Number for Int {
@@ -17,7 +26,7 @@ impl Number for Int {
 }
 
 impl PartialEq<Obj> for Int {
-    fn eq(&self, rhs: &Obj) -> bool {
+    fn eq<'a>(&self, rhs: &'a Obj) -> bool {
         match rhs.obj().and_then(Object::as_num) {
             Some(num) => self == num,
             None => false
@@ -25,8 +34,8 @@ impl PartialEq<Obj> for Int {
     }
 }
 
-impl PartialEq<Number> for Int {
-    fn eq(&self, rhs: &Number) -> bool {
+impl<'a> PartialEq<Number + 'a> for Int {
+    fn eq(&self, rhs: &(Number + 'a)) -> bool {
         match rhs.as_int() {
             Some(rhs) => *self == *rhs,
             None => false
@@ -36,32 +45,23 @@ impl PartialEq<Number> for Int {
 
 #[cfg(test)]
 mod tests {
-    use super::Int;
-    use number::*;
-    use value::*;
+    use super::*;
 
     #[test]
     fn equal_integers_are_equal() {
-        assert_eq!(Integer(3), Integer(3));
-        assert_ne!(Integer(12), Integer(9));
-        assert_eq!(Integer(4).as_value(), Integer(4).as_value());
-        assert_ne!(Integer(5).as_value(), Integer(7).as_value());
+        assert_eq!(Int(3), Int(3));
+        assert_ne!(Int(12), Int(9));
+        assert_eq!(Obj::new(Int(3)), Obj::new(Int(3)));
+        assert_ne!(Obj::new(Int(3)), Obj::new(Int(4)));
     }
 
     #[test]
     fn integers_are_integers() {
-        assert!(Integer(4).is_complex());
-        assert!(Integer(4).is_real());
-        assert!(Integer(4).is_rational());
-        assert!(Integer(4).is_integer());
-        assert!(Integer(4).is_number());
-        assert!(!Integer(6).is_char());
-        assert!(!Integer(6).is_bool());
+        assert_eq!(Int(4).as_bool(), None);
     }
 
     #[test]
     fn integers_are_exact() {
-        assert!(Integer(4).is_exact());
-        assert!(!Integer(4).is_inexact());
+        assert!(Int(4).is_exact());
     }
 }

types/src/number/mod.rs

@@ -2,13 +2,17 @@
  * Eryn Wells <eryn@erynwells.me>
  */
 
-/// # Numbers
-///
-/// Scheme numbers are complex, literally.
+//! # Numbers
+//!
+//! Scheme numbers are complex, literally. The model it uses is a hierarchy of types called the
+//! Number Tower. It consists of four types, in order: Integers, Rationals (or Fractionals),
+//! Irrationals (or Reals), and Complex Numbers. Each type going down the tower can be
+//! unequivocally cast to the type below it, but the reverse is not necessarily true. So, an
+//! Integer can be cast as a Rational (by putting its value over 1), but a Rational like 1/2 cannot
+//! be represented as an Integer.
 
 mod integer;
 
-use std::fmt;
 use object::Object;
 
 pub use self::integer::Int;
@@ -16,19 +20,10 @@ pub use self::integer::Int;
 pub trait Number: 
     Object
 {
+    /// Cast this Number to an Int if possible.
     fn as_int(&self) -> Option<&Int> { None }
-}
-
-#[derive(Debug, Eq, PartialEq)]
-pub enum Exact { Yes, No }
-
-impl fmt::Display for Exact {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}", match *self {
-            Exact::Yes => "#e",
-            Exact::No => "#i",
-        })
-    }
+    /// Return `true` if this Number is an exact representation of its value.
+    fn is_exact(&self) -> bool { true }
 }
 
 // TODO: Implement PartialEq myself cause there are some weird nuances to comparing numbers.

types/src/object.rs

@@ -44,11 +44,11 @@ pub trait Object:
 }
 
 impl Obj {
-    pub fn new<T: 'static + Object>(obj: T) -> Obj {
+    pub fn new<T: Object + 'static>(obj: T) -> Obj {
         Obj::Ptr(Box::new(obj))
     }
 
-    pub fn obj<'a>(&'a self) -> Option<&'a Object> {
+    pub fn obj<'s, 'r: 's>(&'s self) -> Option<&'r (Object + 's)> {
         match self {
             Obj::Ptr(obj) => Some(obj.deref()),
             Obj::Null => None
@@ -60,7 +60,7 @@ impl Obj {
         mem::replace(self, Obj::Null)
     }
 
-    pub fn unbox_as<T: 'static + Object>(&self) -> Option<&T> {
+    pub fn unbox_as<T: Object + 'static>(&self) -> Option<&T> {
         match self {
             Obj::Null => None,
             Obj::Ptr(obj) => obj.as_any().downcast_ref::<T>()
@@ -188,8 +188,6 @@ impl PartialEq for Obj {
 
 #[cfg(test)]
 mod tests {
-    use super::Obj;
-
 //    #[test]
 //    fn display_bools() {
 //        assert_eq!(format!("{}", Object::Bool(true)), "#t");