def term(tokens):
first = [TType.TTRUE, TType.TFALSE, TType.TVAR, TType.TLPAREN]
follow = [TType.TEOF, TType.TRPAREN, TType.TARROW, TType.TOR, TType.TAND]
e = None
if tokens[0].ttype == TType.TVAR:
e = pred(tokens)
elif tokens[0].ttype == TType.TTRUE:
e = true()
tokens.pop(0)
elif tokens[0].ttype == TType.TFALSE:
e = false()
tokens.pop(0)
elif tokens[0].ttype == TType.TLPAREN:
tokens.pop(0)
e = expr(tokens)
if tokens[0].ttype != TType.TRPAREN:
raise ParseException(tokens[0].pos, [TType.TRPAREN], tokens[0].val)
tokens.pop(0)
elif tokens[0].ttype == TType.TFA or \
tokens[0].ttype == TType.TEX:
e = expr(tokens)
else:
raise ParseException(tokens[0].pos, first, tokens[0].val)
if tokens[0].ttype not in follow:
raise ParseException(tokens[0].pos, follow, tokens[0].val)
return e
def pred(tokens):
follow = [TType.TEOF, TType.TRPAREN, TType.TARROW, TType.TOR, TType.TAND]
e = None
# initial name
name = tokens.pop(0).val
# P(v {, v} )
if tokens[0].ttype == TType.TLPAREN:
tokens.pop(0)
vs = []
if tokens[0].ttype == TType.TVAR:
vs = [tokens.pop(0).val]
# P()
elif tokens[0].ttype == TType.TRPAREN:
pass
else:
raise ParseException(tokens[0].pos, [TType.TVAR], tokens[0].val)
# {, v}
while tokens[0].ttype != TType.TRPAREN:
if tokens[0].ttype == TType.TCOMMA and \
tokens[1].ttype == TType.TVAR:
tokens.pop(0)
vs.append(tokens.pop(0).val)
else:
raise ParseException(tokens[0].pos, [TType.TCOMMA],
tokens[0].val)
tokens.pop(0)
e = Pred(name, vs)
# v
else:
e = Var(name)
if tokens[0].ttype not in follow:
raise ParseException(tokens[0].pos, follow, tokens[0].val)
return e
def expr(tokens):
follow = [TType.TEOF, TType.TRPAREN]
e = None
if tokens[0].ttype == TType.TFA:
if tokens[1].ttype == TType.TVAR:
if tokens[2].ttype == TType.TDOT:
tokens.pop(0)
v = tokens.pop(0).val
tokens.pop(0)
e = Forall(v, expr(tokens))
else:
raise ParseException(tokens[2].pos, [TType.TDOT],
tokens[2].val)
else:
raise ParseException(tokens[1].pos, [TType.TVAR], tokens[1].val)
elif tokens[0].ttype == TType.TEX:
if tokens[1].ttype == TType.TVAR:
if tokens[2].ttype == TType.TDOT:
tokens.pop(0)
v = tokens.pop(0).val
tokens.pop(0)
e = Exists(v, expr(tokens))
else:
raise ParseException(tokens[2].pos, [TType.TDOT],
tokens[2].val)
else:
raise ParseException(tokens[1].pos, [TType.TVAR], tokens[1].val)
else:
e = arrow_expr(tokens)
if tokens[0].ttype not in follow:
raise ParseException(tokens[0].pos, follow, tokens[0].val)
return e
def objectHook(self, dictionary):
"""
Object has method load. If it returns None, then the instance of
the object will be replaced with a dictionary. If load returns value X
that is not none, dictionary will be updated with X.
It is possible to dynamically add dictionaries. If __name__ start with
@, it means that it will be added as dictionary into objectHook. If it
ends with ?, it will be added only if it is not there already.
"""
if "__name__" not in dictionary:
return dictionary
cn = dictionary["__name__"]
if len(cn) > 0 and cn[0] == '@':
if cn[-1] == "?":
cnn = cn[1:-1]
check_if_exists = True
else:
cnn = cn[1:]
check_if_exists = False
del dictionary['__name__']
dictionary['__name__'] = cnn
self.addDictionary(cnn, dictionary, check_if_exists)
return None
if len(cn) > 0 and cn[0] == '#':
res = self.fileRegExp.match(cn)
if not res:
raise ParseException('Unknown function')
res = res.groups()
if len(res) != 1:
raise ParseException('Internal error')
filename = res[0]
if filename in self.files:
filename = self.files[filename]
if len(filename) > 0 and filename[0] == '/':
fn = filename
else:
fn = os.path.join(os.path.dirname(self.filenameStack[-1]),
filename)
return self.load(fn)
if cn in self.objects:
obj = self.objects[cn]()
ret = obj.load(dictionary)
if ret == None:
return obj
return ret
elif cn in self.functions:
ret = self.functions[cn](dictionary)
return ret
elif cn in self.dictionary:
dct = self.dictionary[cn]
if "key" not in dictionary:
raise ParseException("Key not found in dictionary")
ret = dct[dictionary['key']]
return ret
elif cn in self.constants:
return self.constants[cn]
else:
return None
def readClause(tokens):
if tokens[0].ttype != TType.TVAR:
raise ParseException(tokens[0].row, tokens[0].col, [TType.TVAR],
tokens[0].val)
v = tokens.pop(0).val
if tokens[0].ttype == TType.TARROW:
tokens.pop(0)
if tokens[0].ttype != TType.TVAR:
raise ParseException(tokens[0].row, tokens[0].col, [TType.TVAR],
tokens[0].val)
clause = [tokens.pop(0).val]
while tokens[0].ttype != TType.TPERIOD:
if tokens[0].ttype != TType.TCOMMA:
raise ParseException(tokens[0].row, tokens[0].col,
[TType.TVAR], tokens[0].val)
if tokens[1].ttype != TType.TVAR:
raise ParseException(tokens[1].row, tokens[1].col,
[TType.TVAR], tokens[1].val)
clause.append(tokens[1].val)
tokens.pop(0)
tokens.pop(0)
tokens.pop(0)
return (v, clause)
if tokens[0].ttype == TType.TPERIOD:
tokens.pop(0)
return (v, [])
raise ParseException(tokens[0].row, tokens[0].col,
[TType.TARROW, TType.TPERIOD], tokens[0].val)
def and_expr(tokens):
follow = [TType.TEOF, TType.TRPAREN, TType.TARROW, TType.TOR]
lhs = not_expr(tokens)
while tokens[0].ttype == TType.TAND:
tokens.pop(0)
rhs = not_expr(tokens)
lhs = And(lhs, rhs)
if tokens[0].ttype not in follow:
raise ParseException(tokens[0].pos, follow, tokens[0].val)
return lhs
def arrow_expr(tokens):
follow = [TType.TEOF, TType.TRPAREN]
lhs = or_expr(tokens)
if tokens[0].ttype == TType.TARROW:
tokens.pop(0)
rhs = arrow_expr(tokens)
lhs = Arrow(lhs, rhs)
if tokens[0].ttype not in follow:
raise ParseException(tokens[0].pos, follow, tokens[0].val)
return lhs
def not_expr(tokens):
follow = [TType.TEOF, TType.TRPAREN, TType.TARROW, TType.TOR, TType.TAND]
e = None
if tokens[0].ttype == TType.TNOT:
tokens.pop(0)
ne = not_expr(tokens)
e = Not(ne)
else:
e = term(tokens)
if tokens[0].ttype not in follow:
raise ParseException(tokens[0].pos, follow, tokens[0].val)
return e
def load(self, dictionary):
if "__name__" not in dictionary:
raise ParseException("Wrong object type")
if dictionary["__name__"] != self.__class__.__name__:
raise ParseException("Wrong object file")
