characterWalker = function( range , matchWord )
		{
			var walker =
				new CKEDITOR.dom.walker( range );
			walker[ matchWord ? 'guard' : 'evaluator' ] =
				guardDomWalkerNonEmptyTextNode;
			walker.breakOnFalse = true;

			this._ = {
				matchWord : matchWord,
				walker : walker,
				matchBoundary : false
			};
		}
Iterator which walk through the specified range char by char. By
default the walking will not stop at the character boundaries, until
the end of the range is encountered.
@param { CKEDITOR.dom.range } range
@param {Boolean} matchWord Whether the walking will stop at character boundary.