package org.checkerframework.checker.index.qual;
import java.lang.annotation.ElementType;
import java.lang.annotation.Target;
/**
* An integer that is either -1 or is a valid index for each of the given sequences.
*
* <p>The <a
* href="https://docs.oracle.com/javase/8/docs/api/java/lang/String.html#indexOf-java.lang.String-">
* <code>String.indexOf(String)</code></a> method is declared as
*
* <pre><code>
* class String {
* {@literal @}IndexOrLow("this") int indexOf(String str) { ... }
* }
* </code></pre>
*
* <p>Writing {@code @IndexOrLow("arr")} is equivalent to writing {@link
* GTENegativeOne @GTENegativeOne} {@link LTLengthOf @LTLengthOf("arr")}, and that is how it is
* treated internally by the checker. Thus, if you write an {@code @IndexOrLow("arr")} annotation,
* you might see warnings about {@code @GTENegativeOne} or {@code @LTLengthOf}.
*
* @see GTENegativeOne
* @see LTLengthOf
* @checker_framework.manual #index-checker Index Checker
*/
@Target({ElementType.TYPE_USE, ElementType.TYPE_PARAMETER})
public @interface IndexOrLow {
/** Sequences that the annotated expression is a valid index for (or it's -1). */
String[] value() default {};
}