utree eval (utree& ut) const {
phxpr::shared_ptr<runtime_environment> eptr
= ut.get<runtime_environment*>()->checkout();
if (!eptr) {
BOOST_THROW_EXCEPTION
(invalid_placeholder(n, frame, eptr, arity_type::fixed));
}
while (frame != eptr->level()) {
if (!eptr->outer()) {
BOOST_THROW_EXCEPTION
(invalid_placeholder(n, frame, eptr, arity_type::fixed));
}
eptr = eptr->outer();
}
if (eptr->size() <= n) {
BOOST_THROW_EXCEPTION
(invalid_placeholder(n, frame, eptr, arity_type::fixed));
}
return utree((*eptr)[n]);
}
utree eval (utree& ut) const {
phxpr::shared_ptr<runtime_environment> eptr
= ut.get<runtime_environment*>()->checkout();
if (!eptr) {
BOOST_THROW_EXCEPTION
(invalid_local_assignment(n, frame, eptr, arity_type::fixed));
}
while (frame != eptr->level()) {
if (!eptr->outer()) {
BOOST_THROW_EXCEPTION
(invalid_local_assignment(n, frame, eptr, arity_type::fixed));
}
eptr = eptr->outer();
}
if (eptr->size() <= n) {
BOOST_THROW_EXCEPTION
(invalid_local_assignment(n, frame, eptr, arity_type::fixed));
}
(*eptr)[n] = eptr->invoke(value);
// assignment returns unspecified
return utree();
}
utree eval(scope const& env) const
{
scope const* eptr = &env;
utree const& arg = (*eptr)[n];
if (arg.which() != utree_type::function_type)
return utree(boost::ref(arg));
else
return arg.eval(*eptr);
}
utree eval(scope const& env) const
{
scope const* eptr = &env;
while (level != eptr->level())
eptr = eptr->outer();
utree const& arg = (*eptr)[n];
if (arg.which() != utree_type::function_type)
return utree(boost::ref(arg));
else
return arg.eval(*eptr);
}
utree eval(scope const& env) const
{
scope const* eptr = &env;
utree result;
for (std::size_t i = n; i < eptr->size(); ++i)
{
utree const& arg = (*eptr)[i];
if (arg.which() != utree_type::function_type)
result.push_back(utree(boost::ref(arg)));
else
result.push_back(arg.eval(*eptr));
}
return result;
}
function operator()(T const& val) const
{
return scheme::val(utree(val));
}
utree dispatch(A const&, boost::mpl::false_) const
{
return utree(); // cannot apply to non-integral types
}
utree dispatch(A const&, boost::mpl::false_) const
{
return utree(); // cannot apply to non-arithmetic types
}
static function as_function(T const& val)
{
return scheme::val(utree(val));
}
utree eval(scope const& /*env*/) const
{
return utree(boost::ref(val));
}
utree eval (utree const& subject) const {
if (!predicate(subject))
BOOST_THROW_EXCEPTION(assertion_failed());
return utree();
}
utree dispatch(A&, boost::mpl::false_) const
{
// $$$ Throw exception here? $$$
return utree(); // cannot apply to non-integral types
}
utree operator()(A const& a) const
{
// $$$ Throw exception here? $$$
return utree(); // cannot apply to non booleans
}
