Refactor and extend docs

lib/KOReaderSync/ChapterXPathIndexerInternal.h

@@ -0,0 +1,31 @@
+#pragma once
+
+#include <Epub.h>
+#include <expat.h>
+
+#include <memory>
+#include <string>
+
+namespace ChapterXPathIndexerInternal {
+
+std::string toLowerStr(std::string value);
+
+bool isSkippableTag(const std::string& tag);
+bool isWhitespaceOnly(const XML_Char* text, int len);
+
+size_t countVisibleBytes(const XML_Char* text, int len);
+size_t countUtf8Codepoints(const XML_Char* text, int len);
+size_t codepointAtVisibleByte(const XML_Char* text, int len, size_t targetVisibleByte);
+size_t visibleBytesBeforeCodepoint(const XML_Char* text, int len, size_t targetCodepointOffset);
+
+std::string normalizeXPath(const std::string& input);
+std::string removeIndices(const std::string& xpath);
+int pathDepth(const std::string& xpath);
+bool isAncestorPath(const std::string& prefix, const std::string& path);
+
+std::string decompressToTempFile(const std::shared_ptr<Epub>& epub, int spineIndex);
+bool runParse(XML_Parser parser, const std::string& path);
+bool isEntityRef(const XML_Char* text, int len);
+size_t countTotalTextBytes(const std::string& tmpPath);
+
+}  // namespace ChapterXPathIndexerInternal