if (typeof(require) !== 'undefined') { var tree = require('less/tree') }

tree.Element = function Element(combinator, value) {
    this.combinator = combinator instanceof tree.Combinator ?
                      combinator : new(tree.Combinator)(combinator);
    this.value = value.trim();
};
tree.Element.prototype.toCSS = function () {
    return this.combinator.toCSS() + this.value;
};

tree.Combinator = function Combinator(value) {
    if (value === ' ') {
        this.value = ' ';
    } else {
        this.value = value ? value.trim() : "";
    }
};
tree.Combinator.prototype.toCSS = function () {
    switch (this.value) {
        case ''  : return '';
        case ' ' : return ' ';
        case '&' : return '';
        case ':' : return ' :';
        case '::': return '::';
        case '+' : return ' + ';
        case '~' : return ' ~ ';
        case '>' : return ' > ';
    }
};