function Combinator(text, line, col){
    
    SyntaxUnit.call(this, text, line, col, Parser.COMBINATOR_TYPE);

    /**
     * The type of modifier.
     * @type String
     * @property type
     */
    this.type = "unknown";
    
    //pretty simple
    if (/^\s+$/.test(text)){
        this.type = "descendant";
    } else if (text == ">"){
        this.type = "child";
    } else if (text == "+"){
        this.type = "adjacent-sibling";
    } else if (text == "~"){
        this.type = "sibling";
    }

}
Represents a selector combinator (whitespace, +, >).
@namespace parserlib.css
@class Combinator
@extends parserlib.util.SyntaxUnit
@constructor
@param {String} text The text representation of the unit. 
@param {int} line The line of text on which the unit resides.
@param {int} col The column of text on which the unit resides.