org.checkerframework.checker.index.qual.NegativeIndexFor Maven / Gradle / Ivy
package org.checkerframework.checker.index.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;
import org.checkerframework.framework.qual.JavaExpression;
import org.checkerframework.framework.qual.SubtypeOf;
/**
* The annotated expression is between {@code -1} and {@code -a.length - 1}, inclusive, for each
* sequence {@code a} listed in the annotation.
*
* This type should rarely (if ever) be written by programmers. It is inferred by the
* SearchIndexChecker when the result of a call to one of the JDK's binary search methods (like
* {@code Arrays.binarySearch}) is known to be less than zero. For example, consider the following
* code:
*
*
*
* int index = Arrays.binarySearch(array, target);
* if (index < 0) {
* // index's type here is @NegativeIndexFor("array")
* index = index * -1;
* // now index's type is @IndexFor("array")
* }
*
*
* @checker_framework.manual #index-checker Index Checker
*/
@Documented
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE_USE, ElementType.TYPE_PARAMETER})
@SubtypeOf(SearchIndexFor.class)
public @interface NegativeIndexFor {
/**
* Sequences for which this value is a "negative index"; that is, the expression is in the range
* {@code -1} to {@code -a.length - 1}, inclusive, for each sequence {@code a} given here.
*/
@JavaExpression
public String[] value();
}