Fraction class prototype and test (not to be committed).

runtime/lib/integers.dart

Index: runtime/lib/integers.dart
diff --git a/runtime/lib/integers.dart b/runtime/lib/integers.dart
index 0c5b11985bad5dd6648392883097aec8ee5f26cc..22188f9929c5332f7361a4a00b987b046f634471 100644
--- a/runtime/lib/integers.dart
+++ b/runtime/lib/integers.dart
@@ -92,13 +92,16 @@ abstract class _IntegerImplementation {
     return other._greaterThanFromInteger(this);
   }
   bool operator >=(num other) {
-    return (this == other) ||  (this > other);
+    return (this == other) || (this > other);
   }
   bool operator <=(num other) {
     return (this == other) || (this < other);
   }
   bool _greaterThanFromInteger(int other)
       native "Integer_greaterThanFromInteger";
+  bool _greaterThanFromFraction(fraction other) {
+    return other._numerator > (other._denominator * this);
+  }
   bool operator ==(other) {
     if (other is num) {
       return other._equalToInteger(this);
@@ -106,6 +109,9 @@ abstract class _IntegerImplementation {
     return false;
   }
   bool _equalToInteger(int other) native "Integer_equalToInteger";
+  bool _equalToFraction(fraction other) {
+    return (this * other._denominator) == other._numerator;
+  }
   int abs() {
     return this < 0 ? -this : this;
   }
@@ -200,8 +206,11 @@ abstract class _IntegerImplementation {
 
   int toInt() { return this; }
   double toDouble() { return new _Double.fromInteger(this); }
+  fraction toFraction() { return new _Fraction.fromInteger(this); }
+  fraction toPercent() { return new _Fraction._percent(this*100); }
   _Bigint _toBigint() { return new _Bigint._fromInt(this); }
-  num _toBigintOrDouble() { return _toBigint(); }
+  num _toBigintIfInteger() { return _toBigint(); }
+  num _toDoubleOrFraction() { return new _Fraction.fromInteger(this); }
 
   String toStringAsFixed(int fractionDigits) {
     return this.toDouble().toStringAsFixed(fractionDigits);