io.github.dmlloyd.classfile.constantpool.ConstantPool Maven / Gradle / Ivy
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package io.github.dmlloyd.classfile.constantpool;
import java.util.Iterator;
import java.util.NoSuchElementException;
import io.github.dmlloyd.classfile.BootstrapMethodEntry;
import io.github.dmlloyd.classfile.ClassReader;
/**
* Provides read access to the constant pool and bootstrap method table of a
* classfile.
*
* @sealedGraph
* @since 22
*/
public sealed interface ConstantPool extends Iterable
permits ClassReader, ConstantPoolBuilder {
/**
* {@return the entry at the specified index}
*
* @apiNote
* If only a particular type of entry is expected, use {@link #entryByIndex(
* int, Class) entryByIndex(int, Class)}.
*
* @param index the index within the pool of the desired entry
* @throws ConstantPoolException if the index is out of range of the
* constant pool, or is considered unusable
*/
PoolEntry entryByIndex(int index);
/**
* {@return the entry of a given type at the specified index}
*
* @param the entry type
* @param index the index within the pool of the desired entry
* @param cls the entry type
* @throws ConstantPoolException if the index is out of range of the
* constant pool, or the entry is not of the given type
* @since 23
*/
T entryByIndex(int index, Class cls);
/**
* {@return the number of entries in the constant pool}
* {@return the size of the constant pool}
*/
int size();
/**
* {@return an iterator over pool entries}
*/
@Override
default Iterator iterator() {
return new Iterator<>() {
int index = 1;
@Override
public boolean hasNext() {
return index < size();
}
@Override
public PoolEntry next() {
if (!hasNext()) throw new NoSuchElementException();
var e = entryByIndex(index);
index += e.width();
return e;
}
};
}
/**
* {@return the {@link BootstrapMethodEntry} at the specified index within
* the bootstrap method table}
*
* @param index the index within the bootstrap method table of the desired
* entry
* @throws ConstantPoolException if the index is out of range of the
* bootstrap methods
*/
BootstrapMethodEntry bootstrapMethodEntry(int index);
/**
* {@return the number of entries in the bootstrap method table}
*/
int bootstrapMethodCount();
}