Simple HTML Parser

HtmlParser

function HtmlParser(){}
function Stack(){
    this.stac = [];
    this.pop = function(){
        return this.stac.pop();
    };
    this.push = function(item){
        this.stac.push(item);
    };
    this.peek = function(){
        if(!this.empty()){
            return this.stac[this.stac.length - 1];
        }
        else{
            return null;
        }
    };
    this.empty = function(){
        return this.stac.length === 0;
    };
}

var result = [];

//Reference:
//http://pickerel.iteye.com/blog/264252
//http://erik.eae.net/simplehtmlparser/simplehtmlparser.js

HtmlParser.prototype = {
    startTagRe: /^<([^>\s\/]+)((\s+[^=>\s]+(\s*=\s*((\"[^\"]*\")|(\'[^\']*\')|[^>\s]+))?)*)\s*\/?\s*>/m,  
    endTagRe:   /^<\/([^>\s]+)[^>]*>/m,  
    attrRe:     /([^=\s]+)(\s*=\s*((\"([^\"]*)\")|(\'([^\']*)\')|[^>\s]+))?/gm,  
    typeRe:     /^<([^>\s\/]+)[>\s]/m,
    parse: function(s){
        var lc,
            lm,
            rc,
            index,
            o,
            content = '',
            i = 0,
            treatAsChars = false
            stack = new Stack();
        while(s.length > 0){
            //Comment
            if(s.substring(0, 4) === '<!--'){
                index = s.indexOf('-->');
                if(index < 0){
                    treatAsChars = true;
                }
                else{
                    s = s.substring(index + 3);
                    treatAsChars = false;
                }
            }
            //End tag
            else if(s.substring(0, 2) === '</'){
                if(this.endTagRe.test(s)){
                    var eTag;
                    lc = RegExp.leftContext;
                    lm = RegExp.lastMatch;
                    rc = RegExp.rightContext;
                    s = rc;
                    eTag = this.parseEndTag(lm);
                    if(stack.peek() !== null && eTag === result[stack.peek()].type){
                        stack.pop();
                    }
                    console.log(stack);
                    if(content !== ''){
                        o.content = content;
                    }

                    treatAsChars = false;
                }
                else{
                    treatAsChars = true;
                }
            }
            //Start tag
            else if(s.substring(0, 1) === '<'){
                if(this.startTagRe.test(s)){
                    lc = RegExp.leftContext;
                    lm = RegExp.lastMatch;
                    rc = RegExp.rightContext;
                    s = rc;                 
                    treatAsChars = false;
                    o = this.parseStartTag(lm);
                    if(content !== '' && stack.peek() !== null){
                        result[stack.peek()].content = content;
                    }
                    result.push(o);
                    stack.push(i);
                    i++;
                }
                else{
                    treatAsChars = true;
                }
            }
            content = '';
            //If the first char is not '<'
            if(treatAsChars){
                index = s.indexOf('<');
                if(index < 0){
                    s = '';
                }
                else{
                    content = s.substring(0, index);
                    s = s.substring(index);                    
                }
            }

            treatAsChars = true;  
        }
    }, 

    parseStartTag: function(sTag){
        var attrs,
            type,
            obj,
            lm, 
            rc;
        this.typeRe.test(sTag);
        lm = RegExp.lastMatch;
        rc = RegExp.rightContext;
        type = lm.substring(1, lm.length - 1);
        obj = {};
        obj.type = type;
        if(rc.length !== 0){
            this.parseAttrs(rc.substring(0, rc.length - 1).trim(), obj);
        }       
        return obj;
    },

    parseEndTag: function(eTag){
        var lm,
            type;
        this.endTagRe.test(eTag);
        lm = RegExp.lastMatch;
        type = lm.substring(2, lm.length - 1).trim();
        return type;
    }, 

    parseAttrs: function(attrs, obj){
        var lm,
            flag,
            attr;
        while(this.attrRe.test(attrs)){
            lm = RegExp.lastMatch;
            attrs = RegExp.rightContext;
            this.parseAttr(lm, obj);
        }
    },

    parseAttr: function(attr, obj){
        var name,
            equalIndex,
            property;
        equalIndex = attr.indexOf('=');
        name = attr.substring(0, equalIndex).trim();
        property = attr.substring(equalIndex + 1).trim();
        obj[name] = property.substring(1, property.length - 1);
    }
};

//Testing
var parser = new HtmlParser(),
    sample = "<div><ul id='myList'><li class='hello'>Hello</li><li customTag='Earth'>World</li></ul></div><a href='http://famo.us'>Click</a>",
    sample2 = "<div>content of div<ul id='myList'><li class='hello'>Hello</li>content of ul<li customTag='Earth'>World</li></ul></div><a href='http://famo.us'>Click</a>",
    samples = [sample, sample2];
for(var i = 0; i < samples.length; i++){
    console.log('Example Input:\n', samples[i]);
    result = [];
    parser.parse(samples[i]);
    for(var j = 0; j < result.length; j++){
        if(j === 0){
            console.log('result:\n[');
        }
        console.log('', result[j]);
        if(j === result.length - 1){
            console.log(']');
        }
    }
}