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

lib/filterClassesNew.js

Index: lib/filterClassesNew.js
===================================================================
new file mode 100644
--- /dev/null
+++ b/lib/filterClassesNew.js
@@ -0,0 +1,61 @@
+"use strict";
+
+let {
+  _Filter_FromText, _Filter_Normalize, _Filter_get_text, _Filter_get_type,
+  _InvalidFilter_get_reason,
+  _ActiveFilter_get_disabled, _ActiveFilter_set_disabled,
+  _ActiveFilter_get_hitCount, _ActiveFilter_set_hitCount,
+  _ActiveFilter_get_lastHit, _ActiveFilter_set_lastHit
+} = require("./compiled");
+
+let {
+  createClass, wrapCall, stringArg, stringResult, defineProperty,
+  defineStringProperty
+} = require("./compiledTools");
+
+let constructors = Object.create(null);
+
+function filterResult(call)
+{
+  return function()
+  {
+    let result = call.apply(this, arguments);
+    let type = _Filter_get_type(result);
+    if (type in constructors)
+      return new (constructors[type])(result);
+    else
+      throw new Error("Unexpected filter type " + type);
+  };
+}
+
+function createFilterClass(superclass, type, typeId)
+{
+  let result = createClass(superclass);
+  if (type)
+    Object.defineProperty(result.prototype, "type", {get: () => type, enumerable: true});
+  if (typeId)
+    constructors[typeId] = result;
+  return result;
+}
+
+exports.Filter = createFilterClass();
+exports.Filter.fromText = wrapCall(filterResult(stringArg(0, _Filter_FromText)));
+exports.Filter.normalize = wrapCall(stringResult(stringArg(0, _Filter_Normalize)));
+defineStringProperty(exports.Filter, "text", _Filter_get_text);
+
+exports.InvalidFilter = createFilterClass(exports.Filter, "invalid", 1);
+defineStringProperty(exports.InvalidFilter, "text", _InvalidFilter_get_reason);
+
+exports.CommentFilter = createFilterClass(exports.Filter, "comment", 2);
+
+exports.ActiveFilter = createFilterClass(exports.Filter);
+defineProperty(exports.ActiveFilter, "disabled", _ActiveFilter_get_disabled, _ActiveFilter_set_disabled);
+defineProperty(exports.ActiveFilter, "hitCount", _ActiveFilter_get_hitCount, _ActiveFilter_set_hitCount);
+defineProperty(exports.ActiveFilter, "lastHit", _ActiveFilter_get_lastHit, _ActiveFilter_set_lastHit);
+
+exports.RegExpFilter = createFilterClass(exports.ActiveFilter, "blocking", 3);
+exports.WhiteListFilter = createFilterClass(exports.RegExpFilter, "whitelist", 4);
+exports.ElemHideBase = createFilterClass(exports.ActiveFilter);
+exports.ElemHideFilter = createFilterClass(exports.ElemHideBase, "elemhide", 5);
+exports.ElemHideException = createFilterClass(exports.ElemHideBase, "elemhideexception", 6);
+exports.CSSPropertyFilter = createFilterClass(exports.ElemHideBase, "cssproperty", 7);