def impl_arg(engine, first, second, third, continuation):
if isinstance(second, term.Var):
error.throw_instantiation_error()
if isinstance(second, term.Atom):
raise error.UnificationFailed()
if not isinstance(second, term.Term):
error.throw_type_error("compound", second)
if isinstance(first, term.Var):
for i in range(len(second.args)):
arg = second.args[i]
oldstate = engine.heap.branch()
try:
third.unify(arg, engine.heap)
first.unify(term.Number(i + 1), engine.heap)
return continuation.call(engine, choice_point=True)
except error.UnificationFailed:
engine.heap.revert(oldstate)
raise error.UnificationFailed()
elif isinstance(first, term.Number):
num = first.num
if num == 0:
raise error.UnificationFailed
if num < 0:
error.throw_domain_error("not_less_than_zero", first)
if num > len(second.args):
raise error.UnificationFailed()
arg = second.args[num - 1]
third.unify(arg, engine.heap)
else:
error.throw_type_error("integer", first)
return continuation.call(engine, choice_point=False)
def impl_arg(engine, first, second, third, continuation):
if isinstance(second, term.Var):
error.throw_instantiation_error()
if isinstance(second, term.Atom):
raise error.UnificationFailed()
if not isinstance(second, term.Term):
error.throw_type_error("compound", second)
if isinstance(first, term.Var):
for i in range(len(second.args)):
arg = second.args[i]
oldstate = engine.heap.branch()
try:
third.unify(arg, engine.heap)
first.unify(term.Number(i + 1), engine.heap)
return continuation.call(engine, choice_point=True)
except error.UnificationFailed:
engine.heap.revert(oldstate)
raise error.UnificationFailed()
elif isinstance(first, term.Number):
num = first.num
if num == 0:
raise error.UnificationFailed
if num < 0:
error.throw_domain_error("not_less_than_zero", first)
if num > len(second.args):
raise error.UnificationFailed()
arg = second.args[num - 1]
third.unify(arg, engine.heap)
else:
error.throw_type_error("integer", first)
return continuation.call(engine, choice_point=False)
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 impl_functor(engine, t, functor, arity):
if helper.is_atomic(t):
functor.unify(t, engine.heap)
arity.unify(term.Number(0), engine.heap)
elif isinstance(t, term.Term):
functor.unify(term.Atom(t.name), engine.heap)
arity.unify(term.Number(len(t.args)), engine.heap)
elif isinstance(t, term.Var):
if isinstance(functor, term.Var):
error.throw_instantiation_error()
a = helper.unwrap_int(arity)
if a < 0:
error.throw_domain_error("not_less_than_zero", arity)
else:
functor = helper.ensure_atomic(functor)
if a == 0:
t.unify(helper.ensure_atomic(functor), engine.heap)
else:
name = helper.unwrap_atom(functor)
t.unify(term.Term(name, [term.Var() for i in range(a)]),
engine.heap)
def impl_functor(engine, t, functor, arity):
if helper.is_atomic(t):
functor.unify(t, engine.heap)
arity.unify(term.Number(0), engine.heap)
elif isinstance(t, term.Term):
functor.unify(term.Atom(t.name), engine.heap)
arity.unify(term.Number(len(t.args)), engine.heap)
elif isinstance(t, term.Var):
if isinstance(functor, term.Var):
error.throw_instantiation_error()
a = helper.unwrap_int(arity)
if a < 0:
error.throw_domain_error("not_less_than_zero", arity)
else:
functor = helper.ensure_atomic(functor)
if a == 0:
t.unify(helper.ensure_atomic(functor), engine.heap)
else:
name = helper.unwrap_atom(functor)
t.unify(
term.Term(name, [term.Var() for i in range(a)]),
engine.heap)
def from_option_list(engine, options):
# XXX add numbervars support
quoted = False
max_depth = 0
ignore_ops = False
number_vars = False
for option in options:
if (not isinstance(option, Term) or len(option.args) != 1):
error.throw_domain_error('write_option', option)
arg = option.args[0]
if option.name == "max_depth":
try:
max_depth = helper.unwrap_int(arg)
except error.CatchableError:
error.throw_domain_error('write_option', option)
elif (not isinstance(arg, Atom) or
(arg.name != "true" and arg.name != "false")):
error.throw_domain_error('write_option', option)
assert 0, "unreachable"
elif option.name == "quoted":
quoted = arg.name == "true"
elif option.name == "ignore_ops":
ignore_ops = arg.name == "true"
return TermFormatter(engine, quoted, max_depth, ignore_ops)
def from_option_list(engine, options):
# XXX add numbervars support
quoted = False
max_depth = 0
ignore_ops = False
number_vars = False
for option in options:
if (not isinstance(option, Term) or len(option.args) != 1):
error.throw_domain_error('write_option', option)
arg = option.args[0]
if option.name == "max_depth":
try:
max_depth = helper.unwrap_int(arg)
except error.CatchableError:
error.throw_domain_error('write_option', option)
elif (not isinstance(arg, Atom)
or (arg.name != "true" and arg.name != "false")):
error.throw_domain_error('write_option', option)
assert 0, "unreachable"
elif option.name == "quoted":
quoted = arg.name == "true"
elif option.name == "ignore_ops":
ignore_ops = arg.name == "true"
return TermFormatter(engine, quoted, max_depth, ignore_ops)
