Issue 4125 - [emscripten] Convert filter classes to C++

compiled/ElemHideBase.cpp

+#include "ElemHideBase.h"
+#include "ElemHideFilter.h"
+#include "ElemHideException.h"
+#include "StringScanner.h"
+
+ElemHideBase::ElemHideBase(const std::u16string& text,
+    const std::u16string& domains, const std::u16string& selector)
+    : ActiveFilter(text, false), selector(selector)
+{
+  if (!domains.empty())
+    ParseDomains(domains, u',');
+}
+
+Filter::Type ElemHideBase::Parse(const std::u16string& text, size_t* domainsEnd,
+    size_t* selectorStart)
+{
+  StringScanner scanner(text);
+
+  // Domains part
+  loop:
+  while (!scanner.done())
+  {
+    char16_t next = scanner.next();
+    if (next == u'#')
+    {
+      *domainsEnd = scanner.position();
+      break;
+    }
+
+    switch (next)
+    {
+      case u'/':
+      case u'*':
+      case u'|':
+      case u'@':
+      case u'"':
+      case u'!':
+        return Type::UNKNOWN;
+    }
+  }
+
+  bool exception = false;
+  char16_t next = scanner.next();
+  if (next == u'@')
+  {
+    exception = true;
+    next = scanner.next();
+  }
+
+  if (next != u'#')
+    return Type::UNKNOWN;
+
+  // Selector part
+
+  // Selector shouldn't be empty
+  if (scanner.done())
+    return Type::UNKNOWN;
+
+  *selectorStart = scanner.position() + 1;
+  while (!scanner.done())
+  {
+    switch (scanner.next())
+    {
+      case u'{':
+      case u'}':
+        return Type::UNKNOWN;
+    }
+  }
+
+  return exception ? Type::ELEMHIDEEXCEPTION : Type::ELEMHIDE;
+}
+
+ElemHideBase* ElemHideBase::Create(const std::u16string& text)
+{
+  size_t domainsEnd;
+  size_t selectorStart;
+  Type type = Parse(text, &domainsEnd, &selectorStart);
+  if (type == Type::UNKNOWN)
+    return nullptr;
+
+  std::u16string domains(text.substr(0, domainsEnd));
+  std::u16string selector(text.substr(selectorStart));
+  if (type == Type::ELEMHIDEEXCEPTION)
+    return new ElemHideException(text, domains, selector);
+  else
+    return new ElemHideFilter(text, domains, selector);
+}
+
+const std::u16string ElemHideBase::GetSelectorDomain() const
+{
+  std::u16string result;
+  for (auto it = domains.begin(); it != domains.end(); ++it)
+  {
+    if (it->second && !it->first.empty())
+    {
+      if (!result.empty())
+        result.append(u",");
+      result.append(it->first);
+    }
+  }
+  return result;
+}