net.sourceforge.pmd.lang.java.ast.ASTSwitchExpression Maven / Gradle / Ivy
/**
* BSD-style license; for more info see http://pmd.sourceforge.net/license.html
*/
package net.sourceforge.pmd.lang.java.ast;
import net.sourceforge.pmd.lang.ast.NodeStream;
/**
* A switch expression, as introduced in Java 12. This node only occurs
* in the contexts where an expression is expected. In particular,
* switch constructs occurring in statement position are parsed as a
* {@linkplain ASTSwitchStatement SwitchStatement}, and not a
* {@link ASTSwitchExpression SwitchExpression} within a
* {@link ASTExpressionStatement ExpressionStatement}. That is because
* switch statements are not required to be exhaustive, contrary
* to switch expressions.
*
* Their syntax is identical though, and described on {@link ASTSwitchLike}.
*/
public final class ASTSwitchExpression extends AbstractJavaExpr
implements ASTExpression,
ASTSwitchLike {
ASTSwitchExpression(int id) {
super(id);
}
@Override
protected R acceptVisitor(JavaVisitor visitor, P data) {
return visitor.visit(this, data);
}
/**
* Returns a stream of all expressions which can be the value of this
* switch. Eg in the following, the yield expressions are marked by a
* comment.
* {@code
*
* switch (foo) {
* case 1 -> 1; // <- <1>
* case 2 -> 2; // <- <2>
* default -> {
* int i = foo * 2;
* yield i * foo; // <-
* }
* }
*
* }
*
*/
public NodeStream getYieldExpressions() {
return NodeStream.forkJoin(
getBranches(),
br -> br.descendants(ASTYieldStatement.class)
.filter(it -> it.getYieldTarget() == this)
.map(ASTYieldStatement::getExpr),
br -> br.asStream()
.filterIs(ASTSwitchArrowBranch.class)
.map(ASTSwitchArrowBranch::getRightHandSide)
.filterIs(ASTExpression.class)
);
}
}