46 lines
1.1 KiB
Java
46 lines
1.1 KiB
Java
import java.util.Optional;
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class Example {
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public static void main(String[] args) {
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/* should print Hi */
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Optional<String> a = Optional.of("Hi");
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System.out.println(StOptional.reduce(a));
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/* should print null */
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Optional<String> b = Optional.empty();
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System.out.println(StOptional.reduce(b));
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/* should print null */
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Optional<String> c = null;
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System.out.println(StOptional.reduce(c));
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}
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}
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/**
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* Stop Optionals from being used!
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* safely reducing optionals back to their original types.
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*/
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final class StOptional {
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/**
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* Reduce any optional down to it's original type
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*
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* @param o Optional<?> to reduce
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* @return <?> value of optional
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*/
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public static final <T> T reduce(Optional<T> o) {
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return nullish(o) ? null : o.get();
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}
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/**
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* Checks if Optional<?> is null or empty
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*
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* @param o Optional<?>
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* @return boolean true if null or empty, false otherwise
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*/
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public static final boolean nullish(Optional<?> o) {
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if (o == null || o.isEmpty())
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return true;
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return false;
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}
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}
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