package org.checkerframework.framework.qual;
import java.lang.annotation.Annotation;
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;
/**
* A conditional postcondition annotation to indicate that a method ensures that certain expressions
* have a certain qualifier once the method has finished, and if the result is as indicated by
* {@code result}. The expressions for which the annotation must hold after the methods execution
* are indicated by {@code expression} and are specified using a string. The qualifier is specified
* by the {@code qualifier} annotation argument.
*
* <p>Here is an example use:
*
* <pre><code>
* {@literal @}EnsuresQualifierIf(result = true, expression = "#1", qualifier = Odd.class)
* boolean isOdd(final int p1, int p2) {
* return p1 % 2 == 1;
* }
* </code></pre>
*
* <p>This annotation is only applicable to methods with a boolean return type.
*
* @author Stefan Heule
* @see EnsuresQualifiersIf
* @checker_framework.manual #java-expressions-as-arguments Syntax of Java expressions
*/
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.METHOD})
@InheritedAnnotation
public @interface EnsuresQualifierIf {
/**
* The Java expressions for which the qualifier holds if the method terminates with return value
* {@link #result()}.
*
* @checker_framework.manual #java-expressions-as-arguments Syntax of Java expressions
*/
String[] expression();
/**
* The qualifier that is guaranteed to hold if the method terminates with return value {@link
* #result()}.
*/
Class<? extends Annotation> qualifier();
/** The return value of the method that needs to hold for the postcondition to hold. */
boolean result();
}