Implement float is_integer method (#112)

* Implement float is_integer method

* float: modified is_integer method

* float: modified return values of is_integer method

Author: DoDaek

py/float.go

@@ -394,6 +394,20 @@ func (a Float) M__ge__(other Object) (Object, error) {
 	return NotImplemented, nil
 }
 
+// Properties
+func init() {
+	FloatType.Dict["is_integer"] = MustNewMethod("is_integer", func(self Object) (Object, error) {
+		if a, ok := convertToFloat(self); ok {
+			f, err := FloatAsFloat64(a)
+			if err != nil {
+				return nil, err
+			}
+			return NewBool(math.Floor(f) == f), nil
+		}
+		return cantConvert(self, "float")
+	}, 0, "is_integer() -> Return True if the float instance is finite with integral value, and False otherwise.")
+}
+
 // Check interface is satisfied
 var _ floatArithmetic = Float(0)
 var _ conversionBetweenTypes = Float(0)

py/tests/float.py

@@ -34,4 +34,8 @@
 assert str(float("1.00")) == "1.0"
 assert str(float("2.010")) == "2.01"
 
+doc="is_integer"
+assert (1.0).is_integer() == True
+assert (2.3).is_integer() == False
+
 doc="finished"