[pypy-svn] r15939 - in pypy/dist/pypy/objspace/std: . test

[pedronis at codespeak.net]

Author: pedronis
Date: Wed Aug 10 21:27:15 2005
New Revision: 15939

Modified:
   pypy/dist/pypy/objspace/std/floatobject.py
   pypy/dist/pypy/objspace/std/test/test_floatobject.py
Log:
issue91 in-progress

put the sanity logic for pow in floatobject.py itself

the backend now only needs to appropriate code to raise ValueError|OverflowError for math.* implementations
(ll_math.h for genc)



Modified: pypy/dist/pypy/objspace/std/floatobject.py
==============================================================================
--- pypy/dist/pypy/objspace/std/floatobject.py	(original)
+++ pypy/dist/pypy/objspace/std/floatobject.py	Wed Aug 10 21:27:15 2005
@@ -278,15 +278,33 @@
             "pow() 3rd argument not allowed unless all arguments are integers"))
     x = w_float1.floatval
     y = w_float2.floatval
-    try:
-        z = x ** y
-    except OverflowError:
-        raise FailedToImplement(space.w_OverflowError, space.wrap("float power"))
-    except ValueError, e:
-        raise FailedToImplement(space.w_ValueError, space.wrap(str(e))) # xxx
-    except ZeroDivisionError, e:   
-        raise OperationError(space.w_ZeroDivisionError,
-                             space.wrap("0.0 cannot be raised to a negative power"))        
+    z = 1.0
+    if y == 0.0:
+        z = 1.0
+    elif x == 0.0:
+        if y < 0.0:
+            raise FailedToImplement(space.w_ZeroDivisionError,
+                                    space.wrap("0.0 cannot be raised to a negative power"))
+        z = 0.0
+    else:
+        if x < 0.0:
+            if math.floor(y) != y:
+                raise FailedToImplement(space.w_ValueError,
+                                        space.wrap("negative number "
+                                                   "cannot be raised to a fractional power"))
+            if x == -1.0:
+                # xxx what if y is infinity or a NaN
+                if math.floor(y * 0.5) * 2.0 == y:
+                    return space.wrap(1.0)
+                else:
+                    return space.wrap( -1.0)
+        else:
+                try:
+                    z = math.pow(x,y)
+                except OverflowError:
+                    raise FailedToImplement(space.w_OverflowError, space.wrap("float power"))
+                except ValueError:
+                    raise FailedToImplement(space.w_ValueError, space.wrap("float power")) # xxx
 
     return W_FloatObject(space, z)
 

Modified: pypy/dist/pypy/objspace/std/test/test_floatobject.py
==============================================================================
--- pypy/dist/pypy/objspace/std/test/test_floatobject.py	(original)
+++ pypy/dist/pypy/objspace/std/test/test_floatobject.py	Wed Aug 10 21:27:15 2005
@@ -106,3 +106,23 @@
 
     def test_getnewargs(self):
         assert  0.0 .__getnewargs__() == (0.0,)
+
+
+    def test_pow(self):
+        def pw(x, y):
+            return x ** y
+        def espeq(x, y):
+            return not abs(x-y) > 1e05
+        raises(ZeroDivisionError, pw, 0.0, -1)
+        assert pw(0, 0.5) == 0.0
+        assert espeq(pw(4.0, 0.5), 2.0)
+        assert pw(4.0, 0) == 1.0
+        assert pw(-4.0, 0) == 1.0
+        raises(ValueError, pw, -1.0, 0.5)
+        assert pw(-1.0, 2.0) == 1.0
+        assert pw(-1.0, 3.0) == -1.0
+        assert pw(-1.0, 1e200) == 1.0
+        
+        
+        
+