def check_float(self, x):
# check roundtrip
Q = float_pack(x, 8)
y = float_unpack(Q, 8)
assert repr(x) == repr(y)
# check that packing agrees with the struct module
struct_pack8 = struct.unpack('<Q', struct.pack('<d', x))[0]
float_pack8 = float_pack(x, 8)
assert struct_pack8 == float_pack8
# check that packing agrees with the struct module
try:
struct_pack4 = struct.unpack('<L', struct.pack('<f', x))[0]
except OverflowError:
struct_pack4 = "overflow"
try:
float_pack4 = float_pack(x, 4)
except OverflowError:
float_pack4 = "overflow"
assert struct_pack4 == float_pack4
# if we didn't overflow, try round-tripping the binary32 value
if float_pack4 != "overflow":
roundtrip = float_pack(float_unpack(float_pack4, 4), 4)
assert float_pack4 == roundtrip
def test_nans(self):
Q = float_pack(float('nan'), 8)
y = float_unpack(Q, 8)
assert repr(y) == 'nan'
L = float_pack(float('nan'), 4)
z = float_unpack(L, 4)
assert repr(z) == 'nan'
def pack_float(packer, repetitions):
space = packer.space
if repetitions > len(packer.args_w) - packer.args_index:
raise space.error(space.w_ArgumentError, "too few arguments")
for i in xrange(packer.args_index, repetitions + packer.args_index):
w_item = packer.args_w[i]
if not (isinstance(w_item, W_FloatObject)
or isinstance(w_item, W_FixnumObject)):
raise space.error(
space.w_TypeError, "can't convert %s into Float" %
space.getclass(w_item).name)
doubleval = space.float_w(w_item)
l = ["\0"] * size
unsigned = float_pack(doubleval, size)
for i in xrange(size):
l[i] = chr((unsigned >> (i * 8)) & 0xff)
if bigendian:
l.reverse()
packer.result.extend(l)
packer.args_index += repetitions
def pack_float(packer, repetitions):
space = packer.space
if repetitions > len(packer.args_w) - packer.args_index:
raise space.error(space.w_ArgumentError, "too few arguments")
for i in xrange(packer.args_index, repetitions + packer.args_index):
w_item = packer.args_w[i]
if not (isinstance(w_item, W_FloatObject) or isinstance(w_item, W_FixnumObject)):
raise space.error(
space.w_TypeError,
"can't convert %s into Float" % space.getclass(w_item).name
)
doubleval = space.float_w(w_item)
l = ["\0"] * size
unsigned = float_pack(doubleval, size)
for i in xrange(size):
l[i] = chr((unsigned >> (i * 8)) & 0xff)
if bigendian:
l.reverse()
packer.result.extend(l)
packer.args_index += repetitions
