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import java.math.BigDecimal;
import java.util.Optional;
import java.util.stream.Stream;
import org.checkerframework.checker.optional.qual.Present;
/**
* Test case for rule #5: "If an Optional chain has a nested Optional chain, or has an intermediate
* result of Optional, it's probably too complex."
*/
@SuppressWarnings("optional.parameter")
public class Marks5 {
// Each method adds first and second, treating empty as zero, returning an Optional of the sum,
// unless BOTH are empty, in which case return an empty Optional.
Optional<BigDecimal> clever(Optional<BigDecimal> first, Optional<BigDecimal> second) {
@SuppressWarnings({"methodref.inference.unimplemented", "methodref.receiver.invalid"})
Optional<BigDecimal> result =
Stream.of(first, second)
.filter(Optional::isPresent)
.map(Optional::get)
.reduce(BigDecimal::add);
return result;
}
Optional<BigDecimal> clever2(Optional<BigDecimal> first, Optional<BigDecimal> second) {
Stream<Optional<BigDecimal>> s = Stream.of(first, second);
@SuppressWarnings("assignment.type.incompatible")
Stream<@Present Optional<BigDecimal>> filtered =
s.<Optional<BigDecimal>>filter(Optional::isPresent);
Stream<BigDecimal> present = filtered.<BigDecimal>map(Optional::get);
Optional<BigDecimal> result = present.reduce(BigDecimal::add);
return result;
}
Optional<BigDecimal> moreClever(Optional<BigDecimal> first, Optional<BigDecimal> second) {
Optional<BigDecimal> result =
first.map(b -> second.map(b::add).orElse(b)).map(Optional::of).orElse(second);
return result;
}
Optional<BigDecimal> clear(Optional<BigDecimal> first, Optional<BigDecimal> second) {
Optional<BigDecimal> result;
if (!first.isPresent() && !second.isPresent()) {
result = Optional.empty();
} else {
result = Optional.of(first.orElse(BigDecimal.ZERO).add(second.orElse(BigDecimal.ZERO)));
}
return result;
}
}
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