1 files changed, 101 insertions, 0 deletions
diff --git a/core/src/main/java/com/google/googlejavaformat/java/java21/Java21InputAstVisitor.java b/core/src/main/java/com/google/googlejavaformat/java/java21/Java21InputAstVisitor.java
new file mode 100644
index 0000000..897d6ff
--- /dev/null
+++ b/core/src/main/java/com/google/googlejavaformat/java/java21/Java21InputAstVisitor.java
@@ -0,0 +1,101 @@
+/*
+ * Copyright 2023 The google-java-format Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License
+ * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package com.google.googlejavaformat.java.java21;
+
+import com.google.googlejavaformat.OpsBuilder;
+import com.google.googlejavaformat.java.java17.Java17InputAstVisitor;
+import com.sun.source.tree.CaseTree;
+import com.sun.source.tree.ConstantCaseLabelTree;
+import com.sun.source.tree.DeconstructionPatternTree;
+import com.sun.source.tree.DefaultCaseLabelTree;
+import com.sun.source.tree.ExpressionTree;
+import com.sun.source.tree.PatternCaseLabelTree;
+import com.sun.source.tree.PatternTree;
+import com.sun.source.tree.StringTemplateTree;
+import javax.lang.model.element.Name;
+
+/**
+ * Extends {@link Java17InputAstVisitor} with support for AST nodes that were added or modified in
+ * Java 21.
+ */
+public class Java21InputAstVisitor extends Java17InputAstVisitor {
+
+  public Java21InputAstVisitor(OpsBuilder builder, int indentMultiplier) {
+    super(builder, indentMultiplier);
+  }
+
+  @Override
+  protected ExpressionTree getGuard(final CaseTree node) {
+    return node.getGuard();
+  }
+
+  @Override
+  public Void visitDefaultCaseLabel(DefaultCaseLabelTree node, Void unused) {
+    token("default");
+    return null;
+  }
+
+  @Override
+  public Void visitPatternCaseLabel(PatternCaseLabelTree node, Void unused) {
+    scan(node.getPattern(), null);
+    return null;
+  }
+
+  @Override
+  public Void visitConstantCaseLabel(ConstantCaseLabelTree node, Void aVoid) {
+    scan(node.getConstantExpression(), null);
+    return null;
+  }
+
+  @Override
+  public Void visitDeconstructionPattern(DeconstructionPatternTree node, Void unused) {
+    sync(node);
+    scan(node.getDeconstructor(), null);
+    builder.open(plusFour);
+    token("(");
+    builder.breakOp();
+    boolean first = true;
+    for (PatternTree pattern : node.getNestedPatterns()) {
+      if (!first) {
+        token(",");
+        builder.breakOp(" ");
+      }
+      first = false;
+      scan(pattern, null);
+    }
+    builder.close();
+    token(")");
+    return null;
+  }
+
+  @SuppressWarnings("preview")
+  @Override
+  public Void visitStringTemplate(StringTemplateTree node, Void aVoid) {
+    sync(node);
+    scan(node.getProcessor(), null);
+    token(".");
+    token(builder.peekToken().get());
+    return null;
+  }
+
+  @Override
+  protected void variableName(Name name) {
+    if (name.isEmpty()) {
+      token("_");
+    } else {
+      visit(name);
+    }
+  }
+}