def test_recursive_type(self):
variable_length_integer = Choice('variable length integer', [])
variable_length_integer.children = [
Sequence('final byte:', [
Field(None, length=1, constraints=[Equals(0)]),
Field('value:', length=7)],
value=parse('${value:}')),
Sequence('intermediate byte:', [
Field(None, length=1, constraints=[Equals(1)]),
Field('value:', length=7),
Child('next:', variable_length_integer)],
value=parse('(${value:} << 7) + ${next:}'))]
params = ExpressionParameters([variable_length_integer])
range = EntryValueType(variable_length_integer).range(params)
self.assertEqual(None, range.min)
self.assertEqual(None, range.max)
def test_unknown_range(self):
# In this case 'intermediate byte:' has an unknown range, while
# 'final byte:' has a known range. We should attempt to solve
# the smallest range first...
variable_length_integer = Choice('variable length integer', [])
variable_length_integer.children = [
Sequence('final byte:', [
Field(None, length=1, constraints=[Equals(0)]),
Field('value:', length=7)],
value=parse('${value:}')),
Sequence('intermediate byte:', [
Field(None, length=1, constraints=[Equals(1)]),
Field('least significant:', length=7),
Child('most significant:', variable_length_integer)],
value=parse('(${most significant:} * 128) + ${least significant:}'),
constraints=[Minimum(0)])]
self.assertEqual({'${most significant:}':1, '${least significant:}':0},
_solve(variable_length_integer, 1, 128))
self.assertEqual({'${most significant:}':1, '${least significant:}':1},
_solve(variable_length_integer, 1, 129))