interval interval_relation_plugin::meet(interval const& src1, interval const& src2, bool& isempty) {
isempty = false;
if (is_empty(0, src1) || is_infinite(src2)) {
return src1;
}
if (is_empty(0, src2) || is_infinite(src1)) {
return src2;
}
bool l_open = src1.is_lower_open();
bool r_open = src1.is_upper_open();
ext_numeral low = src1.inf();
ext_numeral high = src1.sup();
if (src2.inf() > low || (src2.inf() == low && !l_open)) {
low = src2.inf();
l_open = src2.is_lower_open();
}
if (src2.sup() < high || (src2.sup() == high && !r_open)) {
high = src2.sup();
r_open = src2.is_upper_open();
}
if (low > high || (low == high && (l_open || r_open))) {
isempty = true;
return interval(dep());
}
else {
return interval(dep(), low, l_open, nullptr, high, r_open, nullptr);
}
}
interval interval_relation_plugin::unite(interval const& src1, interval const& src2) {
bool l_open = src1.is_lower_open();
bool r_open = src1.is_upper_open();
ext_numeral low = src1.inf();
ext_numeral high = src1.sup();
if (src2.inf() < low || (src2.inf() == low && l_open)) {
low = src2.inf();
l_open = src2.is_lower_open();
}
if (src2.sup() > high || (src2.sup() == high && r_open)) {
high = src2.sup();
r_open = src2.is_upper_open();
}
return interval(dep(), low, l_open, nullptr, high, r_open, nullptr);
}
interval interval_relation_plugin::widen(interval const& src1, interval const& src2) {
bool l_open = src1.is_lower_open();
bool r_open = src1.is_upper_open();
ext_numeral low = src1.inf();
ext_numeral high = src1.sup();
if (src2.inf() < low || (low == src2.inf() && l_open && !src2.is_lower_open())) {
low = ext_numeral(false);
l_open = true;
}
if (high < src2.sup() || (src2.sup() == high && !r_open && src2.is_upper_open())) {
high = ext_numeral(true);
r_open = true;
}
return interval(dep(), low, l_open, nullptr, high, r_open, nullptr);
}