package org.checkerframework.checker.nullness.qual;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
/**
* Indicates that if the method returns a non-null value, then the value expressions are also
* non-null.
*
* <p><b>WARNING:</b> Type-checking for this annotation is <em>not implemented</em> at present.
*
* <p>Here is an example use:
*
* <pre><code>
* {@literal @}AssertNonNullIfNonNull("id")
* {@literal @}Pure
* public @Nullable Long getId() {
* return id;
* }
* </code></pre>
*
* Note the direction of the implication. This annotation says that if the result is non-null, then
* the variable {@code id} is also non-null. The annotation does not say that if {@code id} is
* non-null, then the result is non-null. (There is not currently a way to say the latter, though it
* would also be useful.)
*
* <p>You should <em>not</em> write a formal parameter name or {@code this} as the argument of this
* annotation. In those cases, use the {@link PolyNull} annotation instead.
*
* @see NonNull
* @see PolyNull
* @see org.checkerframework.checker.nullness.NullnessChecker
* @checker_framework.manual #nullness-checker Nullness Checker
*/
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface AssertNonNullIfNonNull {
/**
* Java expression(s) that are non-null after the method returns a non-null vlue.
*
* @checker_framework.manual #java-expressions-as-arguments Syntax of Java expressions
*/
String[] value();
}