style(serialize-xml): Add skipValue to NativeXmlReader

commons-serialize-xml/src/main/java/io/gitlab/jfronny/commons/serialize/xml/NativeXmlReader.java

@@ -437,6 +437,62 @@ public class NativeXmlReader implements Closeable {
         }
     }
 
+    public void skipValue() throws IOException {
+        int count = 0;
+        do {
+            int p = peeked;
+            if (p == PEEKED_NONE) {
+                p = doPeek();
+            }
+            switch (p) {
+                case PEEKED_BEGIN_TAG -> {
+                    if (count == 0) {
+                        pathNames[stackSize - 1] = "<skipped>";
+                    }
+                    push(XmlScope.TAG_HEAD);
+                    count++;
+                }
+                case PEEKED_END_TAG, PEEKED_END_TAG_CONCISE -> {
+                    if (count == 0) {
+                        pathNames[stackSize - 1] = null;
+                    }
+                    stackSize--;
+                    count--;
+                }
+                case PEEKED_TEXT -> skipUntil((c, i) -> c == '<');
+                case PEEKED_CDATA -> {
+                    skipUntil((c, i) -> c == ']');
+                    if (pos + 2 < limit || fillBuffer(3)) {
+                        if (buffer[pos] == ']' && buffer[pos + 1] == ']' && buffer[pos + 2] == '>') {
+                            pos += 3;
+                            peeked = PEEKED_NONE;
+                            return;
+                        }
+                    } else {
+                        throw syntaxError("Unterminated CDATA");
+                    }
+                }
+                case PEEKED_ATTRIBUTE_NAME -> {
+                    skipUntil((c, i) -> isName(c, pos + i + 1 < limit ? buffer[pos + i + 1] : '\0') == NameCheck.NONE);
+                    if (count == 0) pathNames[stackSize - 1] = "<skipped>";
+                    peeked = PEEKED_NONE;
+                }
+                case PEEKED_ATTRIBUTE_VALUE -> {
+                    char quote = buffer[pos++];
+                    skipUntil((c, i) -> c == quote);
+                    pos++;
+                    peeked = PEEKED_NONE;
+                }
+                case PEEKED_EOF -> throw new IllegalStateException("Attempt to skip led outside the document");
+                default -> {}
+            }
+            peeked = PEEKED_NONE;
+        } while (count > 0);
+
+        pathIndices[stackSize - 1]++;
+        if (count < 0) throw new IllegalStateException("Attempt to skip led outside its parent");
+    }
+
     private String nextName() throws IOException {
         return readUntil((c, i) -> isName(c, pos + i + 1 < limit ? buffer[pos + i + 1] : '\0') == NameCheck.NONE, false);
     }
@@ -497,6 +553,38 @@ public class NativeXmlReader implements Closeable {
         return result;
     }
 
+    private void skipUntil(EndPredicate character) throws IOException {
+        int i = 0;
+        findEnd:
+        while (true) {
+            for (; pos + i < limit; i++) {
+                char c = buffer[pos + i];
+                if (character.test(c, i)) {
+                    break findEnd;
+                } else if (c == '\n') {
+                    lineNumber++;
+                    lineStart = pos + i + 1;
+                }
+            }
+
+            // Attempt to load the entire name into the buffer at once.
+            if (i < buffer.length) {
+                if (fillBuffer(i + 1)) {
+                    continue;
+                } else {
+                    break;
+                }
+            }
+
+            pos += i;
+            i = 0;
+            if (!fillBuffer(1)) {
+                break;
+            }
+        }
+        pos += i;
+    }
+
     /**
      * Returns the next character in the stream that is neither whitespace nor a part of a comment.
      * When this returns, the returned character is always at {@code buffer[pos-1]}; this means the