def add_rule(self, ruleterm, end=True):
module = self.modulewrapper.current_module
rule = self.make_rule(ruleterm, module)
signature = rule.signature
if self.get_builtin(signature):
error.throw_permission_error(
"modify", "static_procedure", rule.head.get_prolog_signature())
function = module.lookup(signature)
function.add_rule(rule, end)
return rule
def add_rule(self, ruleterm, end=True):
module = self.modulewrapper.current_module
rule = self.make_rule(ruleterm, module)
signature = rule.signature
if self.get_builtin(signature):
error.throw_permission_error("modify", "static_procedure",
rule.head.get_prolog_signature())
function = module.lookup(signature) #adding to module.functions
function.add_rule(rule, end) #adding to rulechain
return rule
def unwrap_instream(engine, obj):
if isinstance(obj, term.Var):
error.throw_instantiation_error()
if isinstance(obj, term.Atom):
try:
stream = engine.streamwrapper.aliases[obj.name()]
except KeyError:
pass
else:
if not isinstance(stream, PrologInputStream):
error.throw_permission_error("input", "stream",
term.Atom(stream.alias))
assert isinstance(stream, PrologInputStream)
return stream
error.throw_domain_error("stream", obj)
def unwrap_outstream(engine, obj):
if isinstance(obj, term.Var):
error.throw_instantiation_error()
if isinstance(obj, term.Atom):
try:
stream = engine.streamwrapper.aliases[obj.name()]
except KeyError:
pass
else:
if not isinstance(stream, PrologOutputStream):
error.throw_permission_error("output", "stream",
term.Atom(stream.alias))
assert isinstance(stream, PrologOutputStream)
return stream
error.throw_domain_error("stream", obj)
def impl_abolish(engine, heap, module, predicate):
modname = None
if predicate.signature().eq(prefixsig):
modname, predicate = unpack_modname_and_predicate(predicate)
name, arity = helper.unwrap_predicate_indicator(predicate)
if arity < 0:
error.throw_domain_error("not_less_than_zero", term.Number(arity))
signature = Signature.getsignature(name, arity)
if signature.get_extra("builtin"):
error.throw_permission_error("modify", "static_procedure", predicate)
if modname is not None:
module = engine.modulewrapper.get_module(modname, predicate)
try:
del module.functions[signature]
except KeyError:
pass
def impl_abolish(engine, heap, module, predicate):
modname = None
if predicate.signature().eq(prefixsig):
modname, predicate = unpack_modname_and_predicate(predicate)
name, arity = helper.unwrap_predicate_indicator(predicate)
if arity < 0:
error.throw_domain_error("not_less_than_zero", term.Number(arity))
signature = Signature.getsignature(name, arity)
if signature.get_extra("builtin"):
error.throw_permission_error("modify", "static_procedure",
predicate)
if modname is not None:
module = engine.modulewrapper.get_module(modname, predicate)
try:
del module.functions[signature]
except KeyError:
pass
def impl_retract(engine, heap, module, pattern):
modname = None
if pattern.signature().eq(prefixsig):
modname, pattern = unpack_modname_and_predicate(pattern)
assert isinstance(pattern, term.Callable)
if helper.is_term(pattern) and pattern.signature().eq(implsig):
head = helper.ensure_callable(pattern.argument_at(0))
body = helper.ensure_callable(pattern.argument_at(1))
else:
head = pattern
body = None
assert isinstance(head, term.Callable)
if head.signature().get_extra("builtin"):
error.throw_permission_error("modify", "static_procedure",
head.get_prolog_signature())
if modname is None:
function = module.lookup(head.signature())
else:
function = engine.modulewrapper.get_module(modname,
pattern).lookup(head.signature())
if function.rulechain is None:
raise error.UnificationFailed
rulechain = function.rulechain
oldstate = heap.branch()
while rulechain:
rule = rulechain
# standardizing apart
try:
deleted_body = rule.clone_and_unify_head(heap, head)
if body is not None:
body.unify(deleted_body, heap)
except error.UnificationFailed:
oldstate.revert_upto(heap)
else:
if function.rulechain is rulechain:
function.rulechain = rulechain.next
else:
function.remove(rulechain)
break
rulechain = rulechain.next
else:
raise error.UnificationFailed()
def impl_retract(engine, heap, module, pattern):
modname = None
if pattern.signature().eq(prefixsig):
modname, pattern = unpack_modname_and_predicate(pattern)
assert isinstance(pattern, term.Callable)
if helper.is_term(pattern) and pattern.signature().eq(implsig):
head = helper.ensure_callable(pattern.argument_at(0))
body = helper.ensure_callable(pattern.argument_at(1))
else:
head = pattern
body = None
assert isinstance(head, term.Callable)
if head.signature().get_extra("builtin"):
error.throw_permission_error("modify", "static_procedure",
head.get_prolog_signature())
if modname is None:
function = module.lookup(head.signature())
else:
function = engine.modulewrapper.get_module(modname, pattern).lookup(
head.signature())
if function.rulechain is None:
raise error.UnificationFailed
rulechain = function.rulechain
oldstate = heap.branch()
while rulechain:
rule = rulechain
# standardizing apart
try:
deleted_body = rule.clone_and_unify_head(heap, head)
if body is not None:
body.unify(deleted_body, heap)
except error.UnificationFailed:
oldstate.revert_upto(heap)
else:
if function.rulechain is rulechain:
function.rulechain = rulechain.next
else:
function.remove(rulechain)
break
rulechain = rulechain.next
else:
raise error.UnificationFailed()
