io.github.dmlloyd.classfile.MethodTransform Maven / Gradle / Ivy
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package io.github.dmlloyd.classfile;
import java.util.function.Consumer;
import java.util.function.Predicate;
import java.util.function.Supplier;
import io.github.dmlloyd.classfile.impl.TransformImpl;
import io.github.dmlloyd.classfile.extras.PreviewFeature;
/**
* A transformation on streams of {@link MethodElement}.
*
* @see ClassFileTransform
*
* @since 22
*/
@PreviewFeature(feature = PreviewFeature.Feature.CLASSFILE_API)
@FunctionalInterface
public non-sealed interface MethodTransform
extends ClassFileTransform {
/**
* A method transform that sends all elements to the builder.
*/
MethodTransform ACCEPT_ALL = new MethodTransform() {
@Override
public void accept(MethodBuilder builder, MethodElement element) {
builder.with(element);
}
};
/**
* Create a stateful method transform from a {@link Supplier}. The supplier
* will be invoked for each transformation.
*
* @param supplier a {@link Supplier} that produces a fresh transform object
* for each traversal
* @return the stateful method transform
*/
static MethodTransform ofStateful(Supplier supplier) {
return new TransformImpl.SupplierMethodTransform(supplier);
}
/**
* Create a method transform that passes each element through to the builder,
* and calls the specified function when transformation is complete.
*
* @param finisher the function to call when transformation is complete
* @return the method transform
*/
static MethodTransform endHandler(Consumer finisher) {
return new MethodTransform() {
@Override
public void accept(MethodBuilder builder, MethodElement element) {
builder.with(element);
}
@Override
public void atEnd(MethodBuilder builder) {
finisher.accept(builder);
}
};
}
/**
* Create a method transform that passes each element through to the builder,
* except for those that the supplied {@link Predicate} is true for.
*
* @param filter the predicate that determines which elements to drop
* @return the method transform
*/
static MethodTransform dropping(Predicate filter) {
return (b, e) -> {
if (!filter.test(e))
b.with(e);
};
}
/**
* Create a method transform that transforms {@link CodeModel} elements
* with the supplied code transform.
*
* @param xform the method transform
* @return the class transform
*/
static MethodTransform transformingCode(CodeTransform xform) {
return new TransformImpl.MethodCodeTransform(xform);
}
/**
* @implSpec
* The default implementation returns this method transform chained with another
* method transform from the argument. Chaining of two transforms requires to
* involve a chained builder serving as a target builder for this transform
* and also as a source of elements for the downstream transform.
*/
@Override
default MethodTransform andThen(MethodTransform t) {
return new TransformImpl.ChainedMethodTransform(this, t);
}
}