| 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; |
| |
| /** |
| * An integer that, for each of the given sequences, is equal to the sequence's length. |
| * |
| * <p>This is treated as an {@link IndexOrHigh} annotation internally. This is an implementation |
| * detail that may change in the future, when this type may be used to implement more precise |
| * refinements. |
| * |
| * <p>The usual use case for the {@code LengthOf} annotation is in the defintions of custom |
| * collections. Consider the signature of java.lang.String#length(): |
| * |
| * <pre> |
| * |
| * {@code public @LengthOf("this") int length()} |
| * </pre> |
| * |
| * @checker_framework.manual #index-checker Index Checker |
| */ |
| @Documented |
| @Retention(RetentionPolicy.RUNTIME) |
| // Has target of METHOD so that it is stored as a declaration annotation and the SameLen Checker can |
| // read it. |
| @Target({ElementType.TYPE_USE, ElementType.TYPE_PARAMETER, ElementType.METHOD}) |
| public @interface LengthOf { |
| /** Sequences that the annotated expression is equal to the length of. */ |
| String[] value(); |
| } |