Issue 6992 - Remove keyword-by-filter map

lib/filterClasses.js

Index: lib/filterClasses.js
===================================================================
--- a/lib/filterClasses.js
+++ b/lib/filterClasses.js
@@ -677,26 +677,17 @@
 exports.RegExpFilter = RegExpFilter;
 
 RegExpFilter.prototype = extend(ActiveFilter, {
   /**
    * Number of filters contained, will always be 1 (required to
    * optimize {@link Matcher}).
    * @type {number}
    */
-  length: 1,
-
-  /**
-   * The filter itself (required to optimize {@link Matcher}).
-   * @type {RegExpFilter}
-   */
-  get 0()
-  {
-    return this;
-  },
+  size: 1,
 
   /**
    * @see ActiveFilter.domainSeparator
    */
   domainSeparator: "|",
 
   /**
    * Expression from which a regular expression should be generated -
@@ -774,16 +765,25 @@
     return (this.contentType & typeMask) != 0 &&
            (this.thirdParty == null || this.thirdParty == thirdParty) &&
            this.isActiveOnDomain(docDomain, sitekey) &&
            this.regexp.test(location);
   }
 });
 
 /**
+ * Yields the filter itself (required to optimize {@link Matcher}).
+ * @yields {RegExpFilter}
+ */
+RegExpFilter.prototype[Symbol.iterator] = function*()
+{
+  yield this;
+};
+
+/**
  * Creates a RegExp filter from its text representation
  * @param {string} text   same as in Filter()
  * @return {Filter}
  */
 RegExpFilter.fromText = function(text)
 {
   let blocking = true;
   let origText = text;