def impl_if(engine, if_clause, then_clause, continuation):
oldstate = engine.heap.branch()
try:
engine.call(if_clause)
except error.UnificationFailed:
engine.heap.revert(oldstate)
raise
return engine.call(helper.ensure_callable(then_clause), continuation,
choice_point=False)
def impl_if(engine, if_clause, then_clause, continuation):
oldstate = engine.heap.branch()
try:
engine.call(if_clause)
except error.UnificationFailed:
engine.heap.revert(oldstate)
raise
return engine.call(helper.ensure_callable(then_clause),
continuation,
choice_point=False)
def __init__(self, head, body):
from pypy.lang.prolog.interpreter import helper
assert isinstance(head, Callable)
self.head = head
if body is not None:
body = helper.ensure_callable(body)
self.body = body
else:
self.body = None
self.signature = self.head.signature
if isinstance(head, Term):
self.unify_hash = [arg.get_unify_hash(None) for arg in head.args]
self._does_contain_cut()
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 __init__(self, head, body):
from pypy.lang.prolog.interpreter import helper
assert isinstance(head, Callable)
self.head = head
if body is not None:
body = helper.ensure_callable(body)
self.body = body
else:
self.body = None
self.signature = self.head.signature
if isinstance(head, Term):
self.unify_hash = [arg.get_unify_hash(None) for arg in head.args]
self._does_contain_cut()
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 _call(self, engine):
next_call = self.next_call.dereference(engine.heap)
next_call = helper.ensure_callable(next_call)
return engine.call(next_call, self.continuation, choice_point=False)
def _call(self, engine):
next_call = self.next_call.dereference(engine.heap)
next_call = helper.ensure_callable(next_call)
return engine.call(next_call, self.continuation, choice_point=False)
