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348dc88097
OverflowError while x*x succeeds and produces infinity; apparently these inconsistencies cannot be fixed across ``all'' platforms and there's a widespread feeling that therefore ``every'' platform should keep suffering forevermore. Ah well.
110 lines
4.4 KiB
Python
110 lines
4.4 KiB
Python
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import unittest, struct
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from test import test_support
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class FormatFunctionsTestCase(unittest.TestCase):
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def setUp(self):
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self.save_formats = {'double':float.__getformat__('double'),
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'float':float.__getformat__('float')}
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def tearDown(self):
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float.__setformat__('double', self.save_formats['double'])
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float.__setformat__('float', self.save_formats['float'])
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def test_getformat(self):
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self.assert_(float.__getformat__('double') in
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['unknown', 'IEEE, big-endian', 'IEEE, little-endian'])
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self.assert_(float.__getformat__('float') in
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['unknown', 'IEEE, big-endian', 'IEEE, little-endian'])
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self.assertRaises(ValueError, float.__getformat__, 'chicken')
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self.assertRaises(TypeError, float.__getformat__, 1)
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def test_setformat(self):
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for t in 'double', 'float':
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float.__setformat__(t, 'unknown')
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if self.save_formats[t] == 'IEEE, big-endian':
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self.assertRaises(ValueError, float.__setformat__,
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t, 'IEEE, little-endian')
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elif self.save_formats[t] == 'IEEE, little-endian':
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self.assertRaises(ValueError, float.__setformat__,
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t, 'IEEE, big-endian')
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else:
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self.assertRaises(ValueError, float.__setformat__,
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t, 'IEEE, big-endian')
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self.assertRaises(ValueError, float.__setformat__,
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t, 'IEEE, little-endian')
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self.assertRaises(ValueError, float.__setformat__,
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t, 'chicken')
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self.assertRaises(ValueError, float.__setformat__,
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'chicken', 'unknown')
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BE_DOUBLE_INF = '\x7f\xf0\x00\x00\x00\x00\x00\x00'
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LE_DOUBLE_INF = ''.join(reversed(BE_DOUBLE_INF))
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BE_DOUBLE_NAN = '\x7f\xf8\x00\x00\x00\x00\x00\x00'
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LE_DOUBLE_NAN = ''.join(reversed(BE_DOUBLE_NAN))
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BE_FLOAT_INF = '\x7f\x80\x00\x00'
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LE_FLOAT_INF = ''.join(reversed(BE_FLOAT_INF))
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BE_FLOAT_NAN = '\x7f\xc0\x00\x00'
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LE_FLOAT_NAN = ''.join(reversed(BE_FLOAT_NAN))
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# on non-IEEE platforms, attempting to unpack a bit pattern
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# representing an infinity or a NaN should raise an exception.
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class UnknownFormatTestCase(unittest.TestCase):
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def setUp(self):
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self.save_formats = {'double':float.__getformat__('double'),
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'float':float.__getformat__('float')}
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float.__setformat__('double', 'unknown')
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float.__setformat__('float', 'unknown')
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def tearDown(self):
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float.__setformat__('double', self.save_formats['double'])
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float.__setformat__('float', self.save_formats['float'])
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def test_double_specials_dont_unpack(self):
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for fmt, data in [('>d', BE_DOUBLE_INF),
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('>d', BE_DOUBLE_NAN),
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('<d', LE_DOUBLE_INF),
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('<d', LE_DOUBLE_NAN)]:
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self.assertRaises(ValueError, struct.unpack, fmt, data)
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def test_float_specials_dont_unpack(self):
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for fmt, data in [('>f', BE_FLOAT_INF),
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('>f', BE_FLOAT_NAN),
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('<f', LE_FLOAT_INF),
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('<f', LE_FLOAT_NAN)]:
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self.assertRaises(ValueError, struct.unpack, fmt, data)
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# on an IEEE platform, all we guarantee is that bit patterns
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# representing infinities or NaNs do not raise an exception; all else
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# is accident (today).
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class IEEEFormatTestCase(unittest.TestCase):
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if float.__getformat__("double").startswith("IEEE"):
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def test_double_specials_do_unpack(self):
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for fmt, data in [('>d', BE_DOUBLE_INF),
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('>d', BE_DOUBLE_NAN),
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('<d', LE_DOUBLE_INF),
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('<d', LE_DOUBLE_NAN)]:
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struct.unpack(fmt, data)
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if float.__getformat__("float").startswith("IEEE"):
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def test_float_specials_do_unpack(self):
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for fmt, data in [('>f', BE_FLOAT_INF),
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('>f', BE_FLOAT_NAN),
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('<f', LE_FLOAT_INF),
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('<f', LE_FLOAT_NAN)]:
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struct.unpack(fmt, data)
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def test_main():
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test_support.run_unittest(
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FormatFunctionsTestCase,
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UnknownFormatTestCase,
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IEEEFormatTestCase)
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if __name__ == '__main__':
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test_main()
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