kripkomat/modelbuilder.py

90 lines
2.3 KiB
Python

MODEL = """
MODULE {name}
VAR
state : {{ {states} }};
ASSIGN
init(state) := {initial};
next(state) :=
case
{transitions}
esac;
DEFINE
{properties}
"""
TRAN = " state = {n} : {{{ms}}};"
PROP = """ -- Property "{prop}"
{alias} := {logic};
"""
PROP_LOGIC = "state = {state}"
LTL_FORM = """LTLSPEC
{ltl};
"""
A_UPPERCASE = ord('a')
ALPHABET_SIZE = 26
def _decompose(number):
"""Generate digits from `number` in base alphabet, least significants
bits first.
Since A is 1 rather than 0 in base alphabet, we are dealing with
`number - 1` at each iteration to be able to extract the proper digits.
"""
while number:
number, remainder = divmod(number - 1, ALPHABET_SIZE)
yield remainder
def base_10_to_alphabet(number):
"""Convert a decimal number to its base alphabet representation"""
return ''.join(
chr(A_UPPERCASE + part)
for part in _decompose(number)
)[::-1]
class ModelBuilder:
def __init__(self, states, initial, transitions, properties, ltls=[], name="main"):
self._name = name
self._states = states
self._initial = initial
self._tran = transitions
self._props = properties
self._ltls = ltls
self._propalias = {}
for no,prop in enumerate(properties.keys()):
self._propalias[prop] = base_10_to_alphabet(no + 1)
def generate(self):
# build model
states_decl = ",".join(self._states)
transitions = []
for n,ms in self._tran.items():
transition = TRAN.format(n=n, ms=",".join(ms))
transitions.append(transition)
properties = []
for prop,states in self._props.items():
alias = self._propalias[prop]
logic = " | ".join([PROP_LOGIC.format(state=x) for x in states])
prop_str = PROP.format(prop=prop, alias=alias, logic=logic)
properties.append(prop_str)
out = MODEL.format(name=self._name,
states=states_decl,
initial=self._initial,
transitions="\n".join(transitions),
properties="\n".join(properties))
# add LTL formulas
for ltl in self._ltls:
out += LTL_FORM.format(ltl=ltl)
return out