def impl_abolish(engine, predicate):
from pypy.lang.prolog.builtin import builtins
name, arity = helper.unwrap_predicate_indicator(predicate)
if arity < 0:
error.throw_domain_error("not_less_than_zero", term.Number(arity))
signature = name + "/" + str(arity)
if signature in builtins:
error.throw_permission_error("modify", "static_procedure", predicate)
if signature in engine.signature2function:
del engine.signature2function[signature]
def impl_abolish(engine, predicate):
from pypy.lang.prolog.builtin import builtins
name, arity = helper.unwrap_predicate_indicator(predicate)
if arity < 0:
error.throw_domain_error("not_less_than_zero", term.Number(arity))
signature = name + "/" + str(arity)
if signature in builtins:
error.throw_permission_error("modify", "static_procedure",
predicate)
if signature in engine.signature2function:
del engine.signature2function[signature]
def add_rule(self, rule, end=True):
from pypy.lang.prolog import builtin
if DEBUG:
debug_print("add_rule", rule)
if isinstance(rule, Term):
if rule.name == ":-":
rule = Rule(rule.args[0], rule.args[1])
else:
rule = Rule(rule, None)
signature = rule.signature
elif isinstance(rule, Atom):
rule = Rule(rule, None)
signature = rule.signature
else:
error.throw_type_error("callable", rule)
assert 0, "unreachable" # make annotator happy
if signature in builtin.builtins:
error.throw_permission_error(
"modify", "static_procedure", rule.head.get_prolog_signature())
function = self._lookup(signature)
function.add_rule(rule, end)
def impl_retract(engine, pattern):
from pypy.lang.prolog.builtin import builtins
if isinstance(pattern, term.Term) and pattern.name == ":-":
head = helper.ensure_callable(pattern.args[0])
body = helper.ensure_callable(pattern.args[1])
else:
head = pattern
body = None
if head.signature in builtins:
assert isinstance(head, term.Callable)
error.throw_permission_error("modify", "static_procedure",
head.get_prolog_signature())
function = engine.signature2function.get(head.signature, None)
if function is None:
raise error.UnificationFailed
#import pdb; pdb.set_trace()
rulechain = function.rulechain
while rulechain:
rule = rulechain.rule
oldstate = engine.heap.branch()
# standardizing apart
try:
deleted_body = rule.clone_and_unify_head(engine.heap, head)
if body is not None:
body.unify(deleted_body, engine.heap)
except error.UnificationFailed:
engine.heap.revert(oldstate)
else:
if function.rulechain is rulechain:
if rulechain.next is None:
del engine.signature2function[head.signature]
else:
function.rulechain = rulechain.next
else:
function.remove(rulechain)
break
rulechain = rulechain.next
else:
raise error.UnificationFailed()
def impl_retract(engine, pattern):
from pypy.lang.prolog.builtin import builtins
if isinstance(pattern, term.Term) and pattern.name == ":-":
head = helper.ensure_callable(pattern.args[0])
body = helper.ensure_callable(pattern.args[1])
else:
head = pattern
body = None
if head.signature in builtins:
assert isinstance(head, term.Callable)
error.throw_permission_error("modify", "static_procedure",
head.get_prolog_signature())
function = engine.signature2function.get(head.signature, None)
if function is None:
raise error.UnificationFailed
#import pdb; pdb.set_trace()
rulechain = function.rulechain
while rulechain:
rule = rulechain.rule
oldstate = engine.heap.branch()
# standardizing apart
try:
deleted_body = rule.clone_and_unify_head(engine.heap, head)
if body is not None:
body.unify(deleted_body, engine.heap)
except error.UnificationFailed:
engine.heap.revert(oldstate)
else:
if function.rulechain is rulechain:
if rulechain.next is None:
del engine.signature2function[head.signature]
else:
function.rulechain = rulechain.next
else:
function.remove(rulechain)
break
rulechain = rulechain.next
else:
raise error.UnificationFailed()
def add_rule(self, rule, end=True):
from pypy.lang.prolog import builtin
if DEBUG:
debug_print("add_rule", rule)
if isinstance(rule, Term):
if rule.name == ":-":
rule = Rule(rule.args[0], rule.args[1])
else:
rule = Rule(rule, None)
signature = rule.signature
elif isinstance(rule, Atom):
rule = Rule(rule, None)
signature = rule.signature
else:
error.throw_type_error("callable", rule)
assert 0, "unreachable" # make annotator happy
if signature in builtin.builtins:
error.throw_permission_error("modify", "static_procedure",
rule.head.get_prolog_signature())
function = self.signature2function.get(signature, None)
if function is not None:
self.signature2function[signature].add_rule(rule, end)
else:
self.signature2function[signature] = Function(rule)