def test_undefined_operations(self):
undefined_symbol = special_values.Undefined('name')
self.assertTrue(special_values.is_undefined(undefined_symbol.foo))
self.assertTrue(special_values.is_undefined(undefined_symbol[0]))
self.assertFalse(
special_values.is_undefined(undefined_symbol.__class__))
def test_undefined(self):
undefined_symbol = special_values.Undefined('name')
self.assertEqual(undefined_symbol.symbol_name, 'name')
undefined_symbol2 = special_values.Undefined('name')
self.assertNotEqual(undefined_symbol, undefined_symbol2)
self.assertTrue(special_values.is_undefined(undefined_symbol))
self.assertTrue(special_values.is_undefined(undefined_symbol2))
def _filter_undefined(all_symbols):
"""Returns the names of undefined symbols contained in all_symbols."""
undefined_symbols = [
s.symbol_name
for s in all_symbols
if special_values.is_undefined(s)
]
return undefined_symbols
def _verify_loop_init_vars(values, symbol_names):
"""Ensures that all values in the state are defined when entering a loop."""
for name, value in zip(symbol_names, values):
if value is None:
raise ValueError(
'"{}" may not be None before the loop.'.format(name))
if special_values.is_undefined_return(value):
# Assumption: the loop will only capture the variable which tracks the
# return value if the loop contained a return statement.
# TODO(mdan): This should be checked at the place where return occurs.
raise ValueError(
'return statements are not supported within a TensorFlow loop.'
)
if special_values.is_undefined(value):
raise ValueError(
'"{}" must be defined before the loop.'.format(name))
def protected_func():
"""Calls function and raises an error if undefined symbols are returned."""
results = func()
undefined_symbols = None
if isinstance(results, tuple):
undefined_symbols = _filter_undefined(results)
elif special_values.is_undefined(results):
# Single return value
undefined_symbols = results.symbol_name
if undefined_symbols:
message = ('The following symbols must also be initialized in the %s '
'branch: {}. Alternatively, you may initialize them before '
'the if statement.') % branch_name
message = message.format(undefined_symbols)
raise ValueError(message)
return results