A simple DOM query library with some added complexity

SexyDollar+.js

/*

  SexyDollar Extended library by Witiko
  
    Function $()
      1st argument: "tagName", "#id", ".className", "tagName.className", "@name", "tagName@name"  
      2nd argument: Array / NodeList / Element parentElement (optional)

*/

var $ = (function(getElementsByClassName, arrayIndexOf, undefined) {
  return function collect(query, element) {
    if(typeof query === "string" && query.indexOf(" ") > -1) {
      func = query.split(" ");
      result = [];
      for(i = 0; i < func.length; i++) {
        if(!tempArray) {
          tempArray = collect(func[i], element);
          if(tempArray.length !== undefined) {
            tempArray = tempArray === null?result:[tempArray];
          }
        }
        else {
          result.length = 0;
          for(j = 0; j < tempArray.length; j++) {
            result.push(collect(func[i], tempArray[j]))
          }
          tempArray.length = 0;
          for(j = 0; j < result.length; j++) {
            if(result[j].length !== undefined) {
              for(var k = 0; k < result[j].length; k++) {
                tempArray.push(result[j][k]);
              }
            } else if(result[j] !== null)
              tempArray.push(result[j]);
          }
          result.length = 0;
        }
        if(!tempArray.length) return tempArray;
        for(j = 0; j < tempArray.length; j++) {
          if((Array.prototype.indexOf?result.indexOf(tempArray[j]):arrayIndexOf(result, tempArray[j])) === -1)
            result.push(tempArray[j]);
        }
        tempArray = result.slice(0);
      }
      return result;
    } else {
      var func = query?(/#|\.|@/.exec(query) || [])[0]:null,
          index = query?query.indexOf(func):-1,
          tempArray, tempString, result = [], i, j;
      if(!query || !query.length) query = "*";
      if(!element) element = document;
      else if(!(element.length || (typeof window.HTMLElement === "object"?element instanceof HTMLElement:typeof element === "object" && (element.nodeType === 1 || element.nodeType ===  9) && typeof element.nodeName === "string" && element.hasChildNodes())))
        return func==="#"?null:result;
      switch(func) {
        case ".": 
          if(index === 0) {
            if(element.length) {
              result = element[0].getElementsByClassName?
                element[0].getElementsByClassName(query.substr(1)):
                getElementsByClassName(query.substr(1), false, element[0]);
              for(i = 1; a < element.length; i++) {
                tempArray = element[i].getElementsByClassName?
                  element[i].getElementsByClassName(query.substr(1)):
                  getElementsByClassName(query.substr(1), false, element[i]);
                for(j = 0; tempArray[j]; j++) {
                  if((Array.prototype.indexOf?result.indexOf(tempArray[j]):arrayIndexOf(result, tempArray[j])) === -1)
                    result.push(tempArray[j]);
                }
              }
              return result;
            } else return element.getElementsByClassName?
              element.getElementsByClassName(query.substr(1)):
              getElementsByClassName(query.substr(1), false, element);
          } else {
            tempString = new RegExp(query.substr(0,index), "i");
            if(element.length) {
              for(i = 0; i < element.length; i++) {
                  tempArray = element[i].getElementsByClassName?
                    element[i].getElementsByClassName(query.substr(index + 1)):
                    getElementsByClassName(query.substr(index + 1), query.substr(0,index), element[i]);
                  for(j = 0; tempArray[j]; j++) {
                    if((!element[i].getElementsByClassName || tempString.test(tempArray[i].tagName)) &&
                      (Array.prototype.indexOf?result.indexOf(tempArray[j]):arrayIndexOf(result, tempArray[j])) === -1)
                        result.push(tempArray[j]);
                  }
              }
              return result;
            } else {
              if(element.getElementsByClassName) {
                tempArray = element.getElementsByClassName(query.substr(index + 1));
                for(i = 0; tempArray[i]; i++) {
                  if(tempString.test(tempArray[i].tagName)) result.push(tempArray[i]);
                }
                return result;
              } else
                return getElementsByClassName(query.substr(index + 1), query.substr(0,index), element);
            }
          }
        case "@":
          if(index === 0) {
            if(element.length) {
              for(i = 0; i < element.length; i++) {
                tempArray = result.concat(element[i].getElementsByName(query.substr(1)));
                for(j = 0; tempArray[j]; j++) {
                  if((Array.prototype.indexOf?result.indexOf(tempArray[j]):arrayIndexOf(result, tempArray[j])) === -1)
                    result.push(tempArray[j]);
                }
              }
              return result;
            } else
              return element.getElementsByName(query.substr(1));
          } else {
            tempString = new RegExp(query.substr(0,index), "i");
            if(element.length) {
              for(i = 0; i < element.length; i++) {
                tempArray = element[i].getElementsByName(query.substr(index + 1));
                for(j = 0; tempArray[j]; j++) {
                  if(tempString.test(tempArray[j].tagName)) result.push(tempArray[j]);
                }
              }
              return result;
            } else {
              tempArray = element.getElementsByName(query.substr(index + 1));
              for(var i = 0; tempArray[i]; i++) {
                if(tempString.test(tempArray[i].tagName)) result.push(tempArray[i]);
              }
              return result;
            }
          }
        case "#":
            if(index !== 0) tempString = new RegExp(query.substr(0,index), "i");
            if(element.length) {
              for(i = 0; i < element.length; i++) {
                tempArray = result.concat((element[i].getElementById?element[i]:document).getElementById(query.substr(index + 1)));
                for(j = 0; tempArray[j]; j++) {
                  if((Array.prototype.indexOf?result.indexOf(tempArray[j]):arrayIndexOf(result, tempArray[j])) === -1 &&
                     (index !== 0?tempString.test(tempArray[j].tagName):true)) {
                    result.push(tempArray[j]);
                  }
                }
              }
              return result;
            } else {
              tempArray = (element.getElementById?element:document).getElementById(query.substr(index + 1));
              return index !== 0?(tempString.test(tempArray.tagName)?tempArray:null):tempArray;
            }
        default:
          if(element.length) {
            for(i = 0; i < element.length; i++) {
              tempArray = element[i].getElementsByTagName(query);
              for(j = 0; tempArray[j]; j++) {
                if((Array.prototype.indexOf?result.indexOf(tempArray[j]):arrayIndexOf(result, tempArray[j])) === -1)
                  result.push(tempArray[j]);
              }
            }
            return result;
          } else
            return element.getElementsByTagName(query);
      }
    }
  }
})(function(className, tag, elm) {
  var testClass = new RegExp("(^|\\s)" + className + "(\\s|$)"),
	    tag = tag || "*",
	    elm = elm || document,
	    elements = (tag === "*" && elm.all)? elm.all : elm.getElementsByTagName(tag),
	    returnElements = [],
	    current,
	    length = elements.length;
	for(var i=0; i<length; i++){
		current = elements[i];
		if(testClass.test(current.className)){
			returnElements.push(current);
		}
	}
	return returnElements;
}, function(n,o){
  for(var j=n.length,i=0;i<j&&n[i]!==o;i++);return j<=i?-1:i
});