fix: (Java) Optimize super() code writing.

teletha · Mar 14, 2023 · 3e16baf · 3e16baf
1 parent 4d27de1
commit 3e16baf
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Showing 2 changed files with 43 additions and 2 deletions.
diff --git a/src/main/java/reincarnation/coder/Coder.java b/src/main/java/reincarnation/coder/Coder.java
@@ -17,6 +17,7 @@
 import java.util.Collection;
 import java.util.Deque;
 import java.util.Iterator;
+import java.util.LinkedList;
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
@@ -49,6 +50,9 @@ public abstract class Coder<O extends CodingOption> {
     /** The lazy writers. */
     private final Deque<Ⅲ<Integer, Integer, Runnable>> lazy = new ArrayDeque();
 
+    /** The snapshot state. */
+    private final LinkedList<Integer> snapshots = new LinkedList();
+
     /** The coding options. */
     protected O options = I.make((Class<O>) Model.collectParameters(getClass(), Coder.class)[0]);
 
@@ -205,6 +209,39 @@ protected final void writeLazy(Runnable writer) {
         lazy.addLast(I.pair(builder.length(), indentSize, writer));
     }
 
+    /**
+     * Create a new snapshot point to revert.
+     * 
+     * @param writer
+     */
+    protected final void snapshot(Runnable writer) {
+        // create new snapshot
+        snapshots.addFirst(-builder.length());
+
+        try {
+            writer.run();
+        } finally {
+            int snapshot = snapshots.pollFirst();
+
+            // revert to the latest snapshot
+            if (0 < snapshot) {
+                builder.delete(snapshot, builder.length());
+            }
+        }
+    }
+
+    /**
+     * Revert to the latest snapshot.
+     */
+    protected final void revert() {
+        if (!snapshots.isEmpty()) {
+            int point = snapshots.peekFirst();
+            if (point < 0) {
+                snapshots.set(0, -point);
+            }
+        }
+    }
+
     /**
      * {@inheritDoc}
      */

diff --git a/src/main/java/reincarnation/coder/java/JavaCoder.java b/src/main/java/reincarnation/coder/java/JavaCoder.java
@@ -390,7 +390,9 @@ private Join thrower(Class[] exceptions) {
      */
     @Override
     public void writeStatement(Code<?> code) {
-        line(code, ";", code.comment().map(" // "::concat));
+        snapshot(() -> {
+            line(code, ";", code.comment().map(" //"::concat));
+        });
     }
 
     /**
@@ -651,7 +653,9 @@ public void writeConstructorCall(Constructor constructor, List<? extends Code> p
      */
     @Override
     public void writeSuperConstructorCall(Constructor constructor, List<? extends Code> params) {
-        if (!params.isEmpty()) {
+        if (params.isEmpty()) {
+            revert();
+        } else {
             write("super", buildParameter(constructor, params));
         }
     }