exports.List = function(discriminator) {
    this.discriminator = discriminator;
    this.contents = [];
}

exports.List.prototype.add = function(child){
    if(child.constructor === Array){

        children = child;
        for(child of children){
            if( this.filter( this.discriminator, child[this.discriminator] ).length === 0 )
                this.contents.push(child);
        }

    }else{
        if( this.filter( this.discriminator, child[this.discriminator] ).length === 0 )
            this.contents.push(child);
    }
}

exports.List.prototype.length = function(){
    return this.contents.length;
}

exports.List.prototype.removeIndex = function(index){
    this.contents.splice(index, 1);
}

exports.List.prototype.removeChild = function(child){

    var index = this.contents.indexOf(child);

    if( index === -1 ){
        return false;
    }

    this.removeIndex(index);

}

exports.List.prototype.concatSublists = function(whereList, discriminator){
    //this is meant to look at the contents, and assuming the contents are all lists, concatenate their values.

    var concatList = new exports.List(discriminator);

    for(item of this.contents){
        var itemList = item[whereList];
        concatList.add(itemList.contents);
    }

    return concatList;
}

exports.List.prototype.filter = function(key, value, onlyOne) {

    var results = [];

    for (index in this.contents) {
        var child = this.contents[index];
        if (child[key] == value) {
            if (onlyOne) {
                return child;
            } else {
                results.push(child);
            }
        }
    }

    if(onlyOne){
        return false;
    }

    return results;
}